Lower Limb Anatomy Lab Session 2022 PDF

Lower Limb Anatomy lab session, edition 2022. by Prof. Jerzy Gielecki MD, PhD and Anna Żurada MD, PhD, Michał Ciucias MSc 1 Regions of lower limb 1.1 Buttock or gluteal region 1. Natal cleft 2. Gluteal fold 1.2 Hip or hip region 1.3 Thigh or thigh region 1. Anterior region of thigh or anterior surfa...

Lower Limb Anatomy lab session, edition 2022. by Prof. Jerzy Gielecki MD, PhD and Anna Żurada MD, PhD, Michał Ciucias MSc 1 Regions of lower limb 1.1 Buttock or gluteal region 1. Natal cleft 2. Gluteal fold 1.2 Hip or hip region 1.3 Thigh or thigh region 1. Anterior region of thigh or anterior surface of thigh 2. Femoral triangle 3. Posterior region of thigh or posterior surface of thigh 1.4 Knee or knee region 1. Anterior region of knee 2. Popliteal region or posterior region of knee 3. Popliteal fossa 1.5 Leg region 1. 2. 3. 4. 5. 6. 7. Anterior region of leg or anterior surface of leg Posterior region of leg or psterior surface of leg Calf or sural region Anterior talocrural region or anterior ankle region Posterior talocrural region or posterior ankle region Lateral retromalleolar region Medial retromalleolar region 1.6 Foot or foot region 1. 2. 3. 4. 5. Heel or heel region Dorsum of foot or dorsal region of foot Sole of foot or plantar region of foot Lateral border of foot or fibular border of foot Medial border of foot or tibial border of foot 1.7 Longitudinal arch of foot 1. Lateral part 2. Medial part 1.8 Transverse arch of foot 1. Tarsus or tarsal region 2. Metatarsus or metatarsal region 1 1.9 Toes or digits of foot 1. 2. 3. 4. 5. 6. 7. Great toe or first toe – I Second toe – II Third toe – III Fourth toe – IV Little toe or fifth toe – V Plantar surfaces of toes Dorsal surfaces of toes Fig. 1.1. Regions of lower limb 2 Bones of the lower limb (free part) 2.1 Femur Femur is a long bone with a shaft, proximal and distal ends. It is the longest, largest and the strongest bone of the human skeleton. 2.1.1 Proximal end The proximal end of the femur presents the: 1. Head of femur which forms about two-thirds of a sphere. It is covered by articular cartilage except a small pit located medially at the central part of the head which is called: 2. Fovea for ligament of head of femur or fovea for round ligament. This fovea is the place of attachment for the ligament of head of femur. 3. Neck of femur which connects the head to the shaft at an obtuse angle of about 130 degrees. 4. Greater trochanter which projects upwardly from the junction of the neck with the shaft. It has: a. Trochanteric fossa on its medial aspect 5. Lesser trochanter which lies in the angle between the neck and the shaft. Trochanters are connected by: 6. Intertrochanteric crest on the posterior surface which has a rounded eminence In the middle part called quadrate tubercle , which does not describe the shape, but the attachment place of the quadratus femoris muscle. 2 7. Intertrochanteric line which is located in the front and it extends from the greater trochanter superiorly to medial lip of linea aspera and serves as an attachment place for the ilio- femoral ligament. Fig. 2.1. Proximal end of the femur, superior view. Fig. 2.2. Proximal end of the femur, posteromedial – A and medial – B view. 3 Fig. 2.3. Proximal end of the femur, posterior – A and lateral – B view. 2.1.2 Shaft of femur The shaft of the femur presents the: 1. Linea aspera which is the rough line or ridge on the posterior side of the shaft. It exhibits the: a. Lateral lip b. Medial lip that provides attachments for muscles and intermuscular septa 2. Pectineal line which runs from the lesser trochanter to the medial lip of the linea aspera and provides an insertion for the pectineus muscle. 3. Gluteal tuberosity on the upper part of the shaft just below the intertrochanteric crest runs from the greater trochanter to the lateral lip of the linea aspera. Occasionally at the superior end of the gluteal tuberosity at the level of the lesser trochanter may be present: a. Third trochanter which is a small process where a part of the gluteus maximus attaches 4. Popliteal surface which is on the lower posterior surface with: 5. Lateral supracondylar line makes up the lateral ridge. 6. Medial supracondylar line makes up the medial ridge. 2.2 Distal end of femur The distal end of the femur has two condyles, the: 1. Medial condyle which contains the: 4 a. Medial epicondyle which is located above medial condyle. b. Adductor tubercle which is a small prominence at the bottom of the medial supracondylar line. 2. Lateral condyle with the: a. Lateral epicondyle which is located above lateral condyle. b. Groove for popliteus which is a groove between the lateral condyle and the lateral epicondyle. 3. Patellar surface which is located anteriorly and it articulates with the patella 4. Intercondylar fossa with its superior border: a. Intercondylar line. Fig. 2.4. Distal end of the femur, inferior view. Clinical comments: Loss of calcium at the acetabular fossa and neck of the femur weakens the bones and make them more prone to damage. Fractures of the neck of the femur occur in older adults when bones be- come osteoporotic. There are variations of this condition but often the clinical signs are external rotation, adduction, and shortening of the leg. Fracture of the shaft of femur is a consequence of highenergy direct trauma. 5 Fig. 2.5. Flow chart of the femur structure. 2.3 Patella Patella or knee-cap is a bone of the lower limb, but some authors suggest that it is the largest sesamoid bone. It articulates with the femur but not with the tibia. The patella has the: 1. 2. 3. 4. Base which is located on the superior part of the patella. Apex which is located on the inferior part of the patella. Anterior surface. Articular surface which is located on the posterior side. 6 Fig. 2.6. Patella, anterior – A and posterior – B view. Clinical comments: Dislocation of the patella occurs most often as a lateral dislocation. 2.4 Tibia Tibia (tibia) is the weight-bearing medial bone of the leg. 2.4.1 Proximal end The proximal end forms the: 1. Medial condyle 2. Lateral condyle with the: a. Fibular articular surface for articulation with the head of the fibula 3. Superior articular surface which is separated by: a. Intercondylar eminence which is located in the midline between medial and lateral part of the superior articular surface and it is limited from both sides by the: i. Medial intercondylar tubercle ii. Lateral intercondylar tubercle b. Anterior intercondylar area which is the part in front of the intercondylar eminence. It is attachment place for the anterior cruciate ligament c. Posterior intercondylar area which is the part behind the intercondylar eminence. It is attachment place for the posterior cruciate ligament. Fig. 2.7. Proximal end of the tibia, superior view. 2.4.2 Shaft of tibia 1. Tibial tuberosity which is located in the front on the upper part of the anterior margin. 2. Anterior border 7 3. Medial border 4. Interosseous border which makes a bony framework for the interosseous mambrane of leg with the inetrosseous border of fibula. Between three borders there are three surfaces on the shaft: 5. Medial surface 6. Lateral surface 7. Posterior surface with the: a. Soleal line on the upper part of the posterior surface of the tibia extending downward from the fibular ar- ticular surface to the medial border. It is attachment place for the soleus muscle. 2.4.3 Distal end 1. Inferior articular surface which articulates with superior articular surface of the talus. 2. Medial malleolus with the: a. Malleolar groove for passing tendons of the tibialis posterior and flexor digitorum longus. 3. Articular facet of medial malleous which belongs to the ankle joint. a. Fibular notch which articulates with the fibula. Fig. 2.8. Tibia, posterior view. 8 Fig. 2.9. Distal end of the tibia, inferior view. Fig. 2.10. Transverse section of the tibia and fibula, superior view. 9 Fig. 2.11. Flowchart of the tibia structure. 2.5 Fibula Fibula (fibula) is a long, thin, lateral bone of the leg with the thickened ends. 2.5.1 Proximal end The proximal end forms the: 1. Head of fibula with the: a. Articular surface of head of fibula b. Apex of head of fibula 2. Neck of fibula. 2.5.2 Shaft of fibula The shaft of fibula forms the: 1. Anterior border 2. Interosseous border which makes with the inetrosseous border of tibia bony framework for the interosseous mambrane of the leg 3. Posterior border And between them the: 4. Lateral surface 5. Medial surface 10 6. Posterior surface a. Medial crest which is located in the 2/3 upper part. 2.5.3 Distal end of fibula The distal end is formed by the: 1. Lateral malleolus with the: a. Articular facet of lateral malleolus is a triangular facet at the medial aspect of the malleolus. It forms the lateral part of the ankle joint. b. Malleolar fossa is a depression on the medial aspect of the posterior portion just behind the articular facet of the lateral malleolus. It is an attach- ment place for the posterior talofibular ligament. c. Malleolar groove is on the posterior aspect of the lateral malleolus, behind and laterally to the malleolar fossa. It forms passage for the fibularis longus and brevis. Fig. 2.12. Flow chart of the fibula structure. 11 Fig. 2.13. Fibula, medial view. 2.6 Bones of foot 2.6.1 Tarsal bones The tarsal bones consist of the following seven bones: talus, calcaneus, navicular, cuboid, and three cuneiforms. 2.6.1.1 Talus Talus (talus) or ankle bone transmits the weight of the body from the tibia to other weight-bearing bones of the foot and is the only one tarsal bone without muscle attachments. It has the: 2.6.1.1.1 Head of talus Head of talus (caput tali) is directed distally with the: 1. Navicular articular surface (facies articularis navicularis) 2. Facet for plantar calcaneonavicular ligament (facies articularis ligamenti calcaneonavicularis plantaris) which is located on the inferomedial side 3. Facet for calcaneonavicular part of bifurcate ligament (facies articularis partis calcaneonavicularis ligamenti bifurcati) which is located on the superolateral side 4. Anterior calcanean articular surface (facies articularis calcanea anterior) 2.6.1.1.2 Neck of talus Neck of talus (collum tali) has the the middle calcanean articular surface (facies articularis calcanea media). 12 Fig. 2.14. Right talus, superior view. Fig. 2.15. Right talus, inferior view. Fig. 2.16. Talus, lateral view 2.6.1.1.3 Groove of talus Groove of talus which is a deep groove between the middle and posterior calcanean articular surfaces for attachment of the talocalcaneal interosseous ligament. 13 2.6.1.1.4 Body of talus Body of talus (corpus tali) is cuboidal and distally surrounded by: 1. Trochlea of talus (trochlea tali) with: a. Superior facet (facies superior) 2. Medial malleolar facet (facies malleolaris medialis) 3. Lateral process (processus lateralis tali) with the: a. Lateral malleolar facet (facies malleolaris lateralis) 4. Posterior calcanean articular surface (facies articularis calcanea posterior) 5. Posterior process (processus posterior tali) with the: a. Groove for tendon of flexor hallucis longus (sulcus tendinis musculi flexoris hallucis longi) which separates the posterior process into the: i. Lateral tubercle (tuberculum laterale) which sometimes becomes a separate bone and it is called os trigonum. It is connected with the talus by connective tissue ii. Medial tubercle (tuberculum mediale). Fig. 2.17. Flowchart of the talus structure. 14 2.6.1.2 Calcaneus Calcaneus (calcaneus) is the largest and the strongest bone of the foot that lies inferior to the talus. It forms the heel and articulates with the talus superiorly and with the cuboid anteriorly. 2.6.1.2.1 Posterior surface Posterior surface of the calcaneus presents the: 1. Calcaneal tuberosity or tuber calcanei (tuber calcanei) which extends to the inferior surface and forms the: a. Lateral process of calcaneal tuberosity (processus lateralis tuberis calcanei) b. Medial process of calcaneal tuberosity (processus medialis tuberis calcanei) 2. Calcaneal tubercle (tuberculum calcanei) is located in the anterior part of the calcaneus at its inferomedial side. It is attachment place for the plantar calcaneocuboid ligament. 2.6.1.2.2 Medial surface On the medial surface are present, the: 1. Sustentaculum tali (sustentaculum tali) with passing below: a. Groove for tendon of flexor hallucis longus (sulcus tendinis musculi flexoris hallucis longi). 2.6.1.2.3 Superior surface 1. Calcaneal groove (sulcus calcanei) for the talocalcaneal interosseous ligament between the talus and the calcaneus. It separates the middle and posterior talar articular surfaces. 2. Anterior talar articular surface (facies articularis talaris anterior). 3. Middle talar articular surface (facies articularis talaris media) which is located on the upper side of the sustentaculum tali. 4. Posterior talar articular surface (facies articularis talaris posterior). 5. Fibular trochlea (trochlea fibularis) and just below it. a. Groove for tendon of fibularis longus (sulcus tendinis musculi fibularis longi) with the tendon of fibularis longus passing below the trochlea and the tendon of the fibularis brevis passing above the trochlea. b. Groove for tendon of fibularis brevis (sulcus tendinis musculi fibularis brevis). 2.6.1.2.4 Anterior surface Anterior part of bone has articular surface for cuboid (facies articularis cuboidea) which is located in the front. 15 Fig. 2.18. Calcaneus, posterior view. Fig. 2.19. Calcaneus, medial view. Fig. 2.20. Calcaneus, inferomedial view. 16 Fig. 2.21. Talus and calcaneus, medial view. Fig. 2.22. Flowchart of the calcaneus structure. 2.6.1.3 Navicular bone Navicular (os naviculare) is a boat-shaped tarsal bone lying between the head of the talus and the three cuneiform bones. It has the tuberosity of navicular bone (tuberositas os- sis navicularis) which is located inferiorly, on the medial side. This is attachment place for the tendon of tibialis posterior. 2.6.1.4 Cuboid bone Cuboid (os cuboideum) is the most laterally placed tarsal bone which connects with the calcaneus, 4th and 5th metatarsal bones, lateral cuneiform and navicular. It has the: 1. Tuberosity of cuboid (tuberositas ossis cuboidei) with the: 17 a. Groove for fibularis longus tendon (sulcus tendinis musculi fibularis longi) on plantar surface. 2. Calcaneal process (processus calcanei). 2.6.1.5 Cuneiform bones Cuneiform bones (ossa cuneiformia) are wedge-shaped bones that are related to the transverse arch. Cuneiform bones articulate with the navicular bone posteriorly and with three metatarsals anteriorly. They are designated as the: 1. Medial cuneiform – the largest one; it joins with the navicular, intermediate cuneiform, 1st, 2nd metatrsal bones 2. Intermediate or middle cuneiform – the smallest one; it connects with the navicular, medial and lateral cuneiform, 2nd metatarsal bone 3. Lateral cuneiform – it connects with the navicular, intermediate cuneiform, cuboid, 2nd, 3rd, 4th metatarsal bones. Fig. 2.23. Bones of the foot, inferior – A and superior – B view. 18 Fig. 2.24. Bones of the foot, medial view. Fig. 2.25. Bones of the foot, lateral view. 2.6.1.6 Matatarsus (metatarsal bones) The metatarsus presents five bones the: 1. Base of metatarsal bone (basis metatarsalis) or proximal end: a. Tuberosity of first metatarsal bone (tuberositas ossis metatarsalis primi) b. Tuberosity of fifth metatarsal bone (tuberositas ossis metatarsalis quinti) 2. Shaft of metatarsal bone (corpus metatarsalis) 3. Head of metatarsal bone (caput metatarsalis) or distal end. Clinical comments: Second, third and fourth metatarsal bones fractures are called stress fractures or match fractures. Fifth metatarsal bone fracture is caused by pulling on the tuberosity by the fibularis brevis muscle tendon. 19 Fig. 2.26. Metatarsal bones (numbered 1 to 5) and proximal phalanges, dorsal view. Sesamoid bone – S. 2.6.1.7 Bones of the toes Phalanges or toes are arranged into three rows except for the phalanges of the great toe which has only two rows (missing middle row). There are the: 1. Proximal phalanx (phalanx proximalis) with the: Base of proximal phalanx (basis phalangis proximalis) or proximal end Shaft of proximal phalanx (corpus phalangis proximalis) Head of proximal phalanx (caput phalangis proximalis) 2. Middle phalanx (phalanx media) with the: Base of middle phalanx (basis phalangis mediae) or proximal end Shaft of middle phalanx (corpus phalangis mediae) Head of middle phalanx (caput phalangis mediae) 3. Distal phalanx (phalanx distalis) with the: Base of distal phalanx (basis phalangis distalis) or proximal end Shaft of distal phalanx (corpus phalangis distalis) Head of distal phalanx (caput phalangis distalis) with the: i. Tuberosity of distal phalanx (tuberositas phalangis distalis). Sesamoid is a small ovoid bone surrounded by a tendon and separated from the primary bone by a synovial bursa. The sesamoid bones of the foot are present in the flexor hallucis brevis and fibularis longus tendons. 20 Fig. 2.27. Metatarsal bones (numbered 1 to 5) and proximal phalanges, plantar view. Sesamoid bones – S. Clinical comments: Sesamoid bones can be displaced, broken or dislocated. The sesamoid bones are involved in vari- ous disorders of joints and congenital anomalies. Idiopathic inflammation of the sesamoid bones is called sesamoiditis. 3 Muscles of the lower limb 1. Muscles of lower limb girdle 2. Muscles of thigh a. Anterior compartment of thigh or extensor compartment of thigh b. Posterior compartment of thigh or flexor compartment of thigh c. Medial compartment of thigh or adductor compartment of thigh d. Lateral compartment of thigh or abductor compartment of thigh 3. Muscles of leg 4. Muscles of foot 21 Fig. 3.1. Muscles of thigh - extensor (anterior) compartment of thigh (red), flexor (posterior) compartment of thigh (blue), adductor (medial) compartment of thigh (yellow), abductor (lateral) compartment of thigh - tensor fasciae latae (orange). 3.1 Muscles of lower limb girdle The region behind the hip joint is composed of three gluteal muscles and five muscles which overlie the pelvis. 3.1.1 Muscles of gluteal region 1. Gluteus maximus 2. Gluteus medius 3. Gluteus minimus 4. Gluteal aponeurosis: deep fascia covering the gluteus medius and the gluteus maximus 5. Piriformis 6. Quadratus femoris 7. Gemellus superior 8. Gemellus inferior 9. Obturator internus 10. Obturator externus 3.1.1.1 Gluteus maximus Gluteus maximus is the most superficial muscle of the gluteal region. It is a large flat quadrilateral mass forming the prominence of the buttock. Origin: an extensive area of the gluteal surface of the ala of ilium behind the posterior gluteal line, posterior superior iliac spine and the posterior surfaces of the sacrum, coccyx and sacrotuberous ligament Insertion: the iliotibial tract and the gluteal tuberosity of the femur. Action: a powerful lateral rotator and extensor at the hip joint and acting through the iliotibial tract, it extends and stabilizes the hip joint and knee joint. It acts like an adductor (when inserted on the gluteal tuberosity) and like an abductor (when inserted on the fascia lata). Nerve supply: the inferior gluteal nerve (L5-S2). Arterial supply: Inferior gluteal and superior gluteal arteries. 22 The deep relation of this muscle: It lies behind the hip joint and overlies the gluteus medius, the obturator internus tendon - with the two gemelli, the quadratus femoris, the ischial attachments of the hamstrings, and the structures passing through the greater and lesser sciatic foramina. 3.1.1.2 Gluteus medius (musculus gluteus medius) Origin: the gluteal surface of the ala of ilium between the anterior and posterior gluteal lines Insertion: an oblique ridge on the lateral surface of the greater trochanter. Action: the strongest abductor of the hip joint, anterior part – flexion and medial rotation of the hip joint, posterior part – extention and lateral rotation of the hip joint. Nerve supply: the superior gluteal nerve (L4-L5). Arterial supply: Deep branch of superior gluteal artery, trochanteric anastomosis. 3.1.1.3 Gluteus minimus Gluteus minimus (musculus gluteus minimus) is the deepest of the gluteal muscles and is covered completely by gluteus medius. Origin: gluteal surface of the ala of ilium between the anterior and inferior gluteal lines. Insertion: anterior border of the greater trochanter. Action: abduction of the hip joint, anterior part – functions as flexor and medial rotator of the hip joint, posterior part – extension and lateral rotation of the hip joint. Nerve supply: the superior gluteal nerve (L4-S1). Arterial supply: Superior gluteal artery, trochanteric anastomosis. Fig. 3.2. Innervation of the gluteal muscles 3.1.1.4 Piriformis Piriformis (musculus piriformis) passes laterally through the greater sciatic foramen. Origin: the pelvic surface of the sacrum, lateral to the anterior sacral foramina (II-IV). Insertion: the upper border of the greater trochanter of the femur. Action: rotates thigh laterally, abducts and extends. Nerve supply: direct branches from the sacral plexus. Arterial supply: Superior gluteal artery, inferior gluteal artery, gemellar branches of the internal pudendal. 23 3.1.1.5 Quadratus femoris Quadratus femoris (musculus quadratus femoris) a small muscle helps to stabilize the hip joint. Origin: the lateral, outer edge of the ischial tuberosity. Insertion: the intertrochanteric crest. Action: lateral rotator , extensor and adductor of the thigh. Nerve supply: branch of the sacral plexus (L4(5)-S2), the nerve to quadratus femoris, which also supplies the hip joint. Arterial supply: Inferior gluteal artery 3.1.1.6 Gemellus superior and gemellus inferior The gemelli are two small muscles which lie above and below the obturator internus tendon as it emerges from the lesser sciatic foramen. Medially they are attached to the ischium and laterally merge with the obturator internus tendon. 3.1.1.6.1 Superior gemellus Origin: the ischial spine. Insertion: the trochanteric fossa (the obturator internus tendon). Action: rotates thigh laterally, assist the obturator internus. Nerve supply: branch of the sacral plexus (L4(5)-S2), nerve to obturator internus. Arterial supply: Internal pudendal artery, inferior gluteal artery, sometimes also superior gluteal artery. 3.1.1.6.2 Inferior gemellus Origin: the ischial tuberosity. Insertion: the trochanteric fossa (the obturator internus tendon). Action: rotates thigh laterally and adducts, assist the obturator internus. Nerve supply: branch of the nerve to quadratus femoris (sacral plexus). Arterial supply: Medial circumflex femoral artery. 3.1.1.7 Obturator internus Obturator internus is a layer of muscular fibres converges on the lesser sciatic foramen and groove of the ischium and it turns laterally to leave the pelvis. Origin: pelvic surface of the obturator membrane and the ischiopubic ramus. Insertion: the trochanteric fossa (medial surface of the greater trochanter). Action: adducts and rotates thigh laterally. Nerve supply: nerve to obturator internus, branch of the sacral plexus (L4(5)-S2). Arterial supply: Obturator artery; internal pudendal artery. 24 The gemelli muscle and the obturator internus (all three muscles) sometimes are called the triceps coxae. 3.1.1.8 Obturator externus Obturator externus is a short articular muscle, which lies close to the hip joint, above the adductor brevis. It passes from the outer surface of the obturator membrane and the adjacent bone and its tendon winds below and behind the hip joint to reach a pit on the medial surface of the greater trochanter. Origin: Margin of the obturator foramen and obturator membrane Insertion: Intertrochanteric fossa Action: it supports and stabilises the hip joint and is a weak lateral rotator of the femur Nerve supply: Obturator nerve Arterial supply: Obturator artery, medial circumflex femoral artery. 3.1.2 Muscles of the iliac region Iliopsoas is divided into: 1. Iliacus 2. Psoas major 3. Psoas minor All muscles, which form the iliopsoas, insert into the region of the lesser trochanter. The iliopsoas is a very important muscle because it is a very strong flexor and lateral rotator of the hip joint. The iliopsoas makes walking and running possible (see Fig. 2). 3.1.2.1 Iliacus Iliacus passes under inguinal ligament lateral to the psoas, which forms a common tendon. Origin: the upper two-thirds of the iliac fossa, iliac crest and anterior inferior iliac spine Insertion: lesser trochanter Action: flexion and lateral rotation of the thigh (hip joint) Nerve supply: ventral rami of the lumbar spinal nerves (L2-L4), femoral nerve Arterial supply: Iliolumbar artery, deep circumflex iliac artery, obturator artery, femoral artery. 25 Fig. 3.3. Anterior group of dorsal hip muscle. 3.1.2.2 Psoas major Psoas major is a long fusiform muscle which passes laterally to the vertebral column along pelvic brim, posterior to the inguinal ligament and form the common tendon with iliacus muscle. The psoas major is divided into superficial and deep part. Between this two parts there is the lumbar plexus. Origin: superficial part - vertebral body (Th12-L4) deep part – all costal (transverse) processes of the lumbar vertebrae (L1-L5) Insertion: lesser trochanter of femur Action: flexion and lateral rotation of the thigh Nerve supply: ventral rami of the lumbar spinal nerves (L1-L3), femoral nerve Arterial supply: Lumbar branch of iliolumbar artery. 3.1.2.3 Psoas minor Psoas minor a small muscle lies anterior to the psoas major muscle. Origin: sides of the vertebral bodies of Th12 and the L1 Insertion: iliopectineal eminence, pecten pubis Action: weak flexion of the trunk Nerve supply: a branch of the first lumbar spinal nerve (L1-L3) Arterial supply: Lumbar arteries 26 3.2 Muscles of thigh 3.2.1 Muscles of anterior compartment of thigh There are 3 muscles in the anterior compartment of thigh or extensor compartment of thigh. All muscles are supplied by femoral nerve: 1. Sartorius 2. Quadriceps femoris a. Rectus femoris b. Vastus lateralis c. Vastus intermedius d. Vastus medialis 3. Articularis genu Fig. 3.4. Muscles of the anterior group of the thigh. 3.2.1.1 Sartorius Sartorius is a long strap-like muscle, which in its upper part, forms the lateral boundary of the femoral triangle. Origin: anterior superior iliac spine Insertion: medially to tibial tuberosity and to the front from attachment of gracilis Action: it acts on two joints (the hip and knee joint) as a flexor, a lateral rotator of the femur at the hip joint and rotates medially the leg if the knee joint is flexed Nerve supply: femoral nerve (L2-L3) 27 Arterial supply: 1/3 : Branches of femoral artery, deep femoral artery, lateral circumflex femoral artery. 2/3: Branches of femoral artery. 3/3: Branches of femoral and descending genicular arteries. Fig. 3.5. Muscles of thigh – transverse section. Extensor compartment of thigh (red) – RF (rectus femoris), VL (vastus lateralis), VI (vastus intermedius), VM (vastus medialis). Flexor compartment of thigh (blue) – BFlh (biceps femoris, long head), sh (biceps fe moris, short head), SM (semimembranosus), ST (semitendinosus). Adductor compartment of thigh (yellow) – AL (adductor longus), AM (adductor magnus), G (gracillis). Abductor compartment of thigh - tensor fasciae latae and iliotibial tract (orange). The oblique line of the sartorius passes downwards and medially separating the adductor group of muscles superomedially from the extensor muscles of the knee inferolaterally. Together with the gracillis and the semitendinosus the sartorius forms the pes anserinus. The sartorius forms superficial part of the pes anserinus. 3.2.1.2 Quadriceps femoris Quadriceps femoris is an extensive muscle which forms the bulk of the anterior region of thigh. It is divided into four separate muscles (heads): 3.2.1.2.1 Rectus femoris Rectus femoris lies superficially along the middle part of the thigh in the channel formed by the other three muscle. It is a straight part of the quadriceps femoris and it acts on two joints (the hip and knee joint) Origin: from the anterior inferior iliac spine (straight head) from the ilium just above the acetabulum (reflected head) Insertion: a tendon into the upper border of the patella Action: flexor and abductor at the hip joint; extensor at the knee joint Nerve supply: femoral nerve (L2-L4) Arterial supply: Femoral, lateral femoral circumflex, superficial circumflex iliac arteries. 28 3.2.1.2.2 Vastus lateralis Vastus lateralis lies deep to rectus femoris and also covers the lateral surface of the femoral shaft. Origin: The greater trochanter (the lateral side) and the gluteal tuberosity, and the lateral lip of the linea aspera Insertion: Patella (the lateral side) and forms a tendon with the rectus femoris Action: Extends the leg Nerve supply: Femoral nerve (L2-L4) Arterial supply: Lateral circumflex femoral and deep femoral arteries; artery to quadriceps. 3.2.1.2.3 Vastus medialis Vastus medialis lies deep to rectus femoris and covers the medial surface of the femoral shaft. Origin: The spiral line between the lesser trochanter and the medial lip of the linea aspera, and the medial supracondylar line of the femur. Insertion: Patella (the medial side) and forms a tendon with the rectus femoris. Action: Extends the leg. Nerve supply: Femoral nerve (L2-L4). Arterial supply: Femoral, deep femoral, descending genicular artery. 3.2.1.2.4 Vastus intermedius Vastus intermedius is muscle covers the front of the femur deep to the rectus femoris. Origin: anterior and lateral surfaces of the upper two-thirds of the femoral shaft. Insertion: the upper border of the patella deep to the previous muscles. Action: extends the leg Nerve supply: femoral nerve (L2-L4) Arterial supply: Artery to quadriceps, deep femoral arteries. All four muscles of the quadriceps femoris join together and form the common tendon. The tendon of quadriceps femoris goes down into the patellar ligament attaching to the tibial tuberosity. The lateral part: the latelar patellar retinaculum is formed by fibres of vastus lateralis and lateral fibres of the rectus femoris. The medial part: the medial patellar retinaculum is formed by fibres of vastus medialis and medial fibres of the rectus femoris. The quadriceps femoris attaches to the patella by its tendon forming a single musculotendinous expansion. 3.2.2 Muscles of the Posterior Compartment of Thigh 3.2.2.1 Biceps femoris Biceps femoris is a muscle, which is located laterally on posterior surface of thigh. It contains two heads. Origin: long head – ischial tuberosity short head – lateral lip of linea aspera Insertion: head of fibula Action: it extends and adducts hip joint, flexes and rotates laterally knee joint 29 Nerve supply: Long head – tibial nerve; short head – common fibular nerve. Arterial supply: Inferior gluteal artery, perforating arteries, popliteal artery. 3.2.2.2 Semimebranosus Semimebranosus is located medially on posterior surface of thigh Origin: ischial tuberosity Insertion: medial condyle of tibia Action: it extends and adducts hip joint, flexes and rotates medially knee joint Nerve supply: tibial nerve Arterial supply: Perforating branches of femoral and popliteal arteries. 3.2.2.3 Semitendinosus Semitendinosus is located medially on posterior surface of thigh and passes over semimebranosus. Origin: Ischial tuberosity. Insertion: Medially and below to tibial tuberosity, tendo forms with tendons of gracilis and sartorius pes anserinus. Action: It extends and adducts hip joint and flexes knee joint. Nerve supply: Tibial nerve. Arterial supply: Perforating branch of deep femoral artery, medial femoral circumflex artery, inferior gluteal artery, inferior medial geniculate artery. 30 Fig. 3.6. Muscles of the anterior group of the thigh. Fig. 3.7. Innervation of muscles of thigh – transverse section. Extensor compartment of thigh (red) – RF (rectus femoris), VL (vastus lateralis), VI (vastus intermedius), VM (vastus medialis) – FEMORAL NERVE. Flexor compartment of thigh (blue) – BFlh (biceps femoris, long head), SM (semimembranosus), ST (semitendinosus) – TIBIAL NERVE. Adductor compartment of thigh (yellow) – AL (adductor longus), AM (adductor magnus), G (gracillis) – OBTURATOR NERVE. Abductor compartment of thigh - tensor fasciae latae and iliotibial tract (orange) & BFsh (biceps femoris, short head) – GLUTEAL NERVE & COMMON FIBULAR NERVE (green). 3.2.3 Muscles of the Medial Compartment of the Thigh There are 6 muscles in medial or adductor compartment of thigh: 31 1. 2. 3. 4. 5. 6. Pectineus Adductor longus Adductor brevis Adductor magnus Adductor minimus Gracilis The adductor group of muscles is arranged in three vertical layers; anteriorly pectineus and adductor longus (lies in the same plane) in front of adductor brevis which separates them from the adductor magnus (posteriorly). Gracilis lies superficial to these on the medial side of the thigh. These muscles adduct the femur. In addition pectineus and adductor longus rotates laterally the femur (attached pubis & posterior aspect of the femur), the adductor magnus extends it and the pectineus also helps to flex the femur. 3.2.3.1 Pectineus Pectineus lies medially to iliopsoas. Origin: pecten pubis, pubic tubercle, superior pubic ligament. Insertion: pectineal line between the lesser trochanter and the linea aspera. Action: adduction, flexion and of the thigh. Nerve supply: anterior branch of obturator nerve (L2-L4) and femoral nerves (L2-L3). Arterial supply: Medial femoral circumflex artery, obturator artery. The pectineus and the iliopsoas form the floor of the iliopectinea fossa which is the floor of the femoral triangle. Apex of the iliopsoas fossa goes to the lesser trochanter. 3.2.3.2 Adductor longus Origin: superior ramus and the body of the pubis. Insertion: medial lip of the linea aspera. Action: adduction, lateral rotation and flexion of the thigh. Nerve supply: obturator nerve (anterior branch) – L2-L4. Arterial supply: Deep femoral artery, obturator artery. 3.2.3.3 Adductor brevis Origin: outer surface of the body and the inferior pubic ramus. Insertion: upper half of the medial lip of the linea aspera. Action: adduction, lateral rotation and flexion of the thigh. Nerve supply: obturator nerve (anterior branch) – L2-L4. Arterial supply: Deep femoral artery, 3.2.3.4 Adductor magnus Adductor magnus is the largest and the deepest one. It is the triangular muscle of composite origin, part being derived from the adductor muscles and part from the hamstrings muscles. Origin: a continuous line on the outer surface of the ischiopubic ramus and the ischial tuberosity. Insertion: linea aspera, the medial supracondylar line and by a tendon into the adductor tubercle on the upper aspect of the medial femoral condyle. 32 Action: adduction and extention of the thigh, flexion of the leg, lateral rotation (part attached to the linea aspera), medial rotation (part attached to the medial epicondyle). Nerve supply: Posterior branch of the obturator nerve (part attached to the linea aspera) – L3- L4, and tibial nerve (part attached to the medial epicondyle) – L4- L5. Arterial supply: Deep femoral artery; femoral, popliteal and genicular arteries. 3.2.3.5 Gracilis Gracilis is thin strap-like muscle passes from the inferior border of the ischiopubic ramus to the upper part of the medial surface of the tibia between the attachments of sartorius and semitendinosus. Only one gracillis from all adductors acts on two joints. Origin: body of the inferior pubic ramus Insertion: medial surface of the upper quarter of tibia Action: adduction, flexion of the knee joint, and medial rotation of the leg Nerve supply: anterior branch of the obturator nerve (L2-L4). Arterial supply: Deep femoral artery (adductor branches). 3.2.4 Muscles of Lateral Compartment of the Thigh (tensor fascia lata) There is only 1 muscle in lateral or abductor compartment of thigh: Tensor fascia lata Origin: the anterior quarter of the outer lip of the iliac crest, anterior superior iliac spine. Insertion: lateral condyle of tibia, extends into the iliotibial tract distal to the greater trochanter. Action: it extends and stabilises the knee joint and it flexes, rotates medially and abducts hip joint. It press the head of femur into the acetabulum. Nerve supply: the superior gluteal nerve (L4-L5). Arterial supply: Ascending branch of lateral circumflex femoral artery. The iliotibial tract is a broad thickening of the fascia lata passing from the outer lip of the iliac crest to the anterolateral aspect of the proximal end of the tibia. The iliotibial tract receives the attachments of the tensor fasciae latae and gluteus maximus and these muscles, acting through it, extend and stabilise the knee joint. 4 Nerves of the Lumbo-sacral Plexus The lumbosacral plexus is formed by the ventral rami of the lumbar (L 1-5), sacral (S 1-5) spinal nerves and ventral ramus of coccygeal nerve (C0). The terminal line of the pelvis separates this plexus into lumbar part (lumbar plexus) and sacral part (sacral plexus). The lumbosacral trunk joins two parts of the lumbosacral plexus. The lumbosacral trunk (ventral rami of 4th and 5th lumbar nerves) is this part of the lumbar nerves which descends medial to psoas over the sacrum to join the sacral part of the lumbosacral plexus, so the 4th ventral ramus gives fibres to the lumbar and sacral parts and is often termed nervus furcalis. 33 The lumbar part is upper one of the lumbosacral plexus, which lies between two layers of the psoas major, anterior to the transverse processes of lumbar vertebrae. Fig. 4.1. Relations of the lumbar plexus into the psoas muscles. 4.1 Branches of lumbo-sacral plexus 4.1.1 Lumbar part The lumbar plexus gives the following branches: 1. Muscular branches supply the quadratus lumborum psoas major, minor and iliacus muscles. 2. Iliohypogastric nerve pass laterally around posterior abdominal wall, it pierces the transversus abdominis to run on the posterior surface of the internal oblique muscle. It supplies these muscles and skin above the pubis and gluteal region. 3. ilioinguinal nerve pass laterally and pierces transversus abdominis and internal oblique muscle to run on the posterior surface of the external oblique muscle, it traverse the inguinal canal beneath spermatic cord or round ligament, emerging from superficial ring. It supplies these muscles and skin the genitalia by anterior scrotal or anterior labial branches (!). 4. Genitofemoral nerve descends on the anterior surface of the psoas. It gives off: a. Genital branch traverses the inguinal canal to supply cremaster and the skin of the scrotum or labium majoris 34 b. Femoral branch passes behind the inguinal ligament to supply the skin covering genitalia and femoral triangle. 5. Lateral femoral cutaneous nerve descends on iliacus to enter the thigh deep to the lateral end of the inguinal ligament. It supplies the parietal peritoneum of the iliac fossa and the lateral region of the thigh. 6. Obturator nerve is a branch (L2, L3, L4) descends in the pelvis medially (!) to the psoas major and runs along the lateral wall of the obturator canal through which it passes to reach the thigh. It passes between the internal iliac vessels and the lateral pelvic wall above the obturator artery. In female the obturator nerve lies lateral to the ovary. It gives no branches in the pelvis. It enters the thigh through the obturator groove where it divides into: a. Anterior division: It descends between pectineus and adductor longus anteriorly and adductor brevis posteriorly to end in the subsartorial plexus on the medial side of the thigh. It gives the following branches: Muscular: to gracilis, adductor brevis and adductor longus. Cutaneous: to the 1/3 distal surface of the medial side of the thigh. b. Posterior division: It pierces obturator externus and descends between adductor brevis anteriorly and adductor magnus posteriorly. It later descends with the femoral and then popliteal arteries to the knee joint. It gives the following branches: Muscular: to obturator externus and adductor magnus. Articular: to the knee joint. Articular: to the hip joint 7. Femoral nerve (L2, L3, L4) descends in the pelvis in the groove between psoas and iliacus, and enters the thigh deep to the inguinal ligament. Here it lies on iliacus lateral to the femoral artery. After a short course, it divides into a number of terminal branches which are separated into superficial and deep groups by the lateral circumflex femoral artery. It gives the following branches: a. Anterior cutaneous branches b. Muscular branches: to iliacus, psoas major, pectineus, sartorius, rectus femoris, vastus lateralis vastus intermedius and vastus medialis (= pectineus, sartorius & quadriceps). c. Saphenous nerve is the largest branch of the femoral nerve. It accompanies the femoral artery through the femoral triangle and subsartorial canal and just above the knee it emerges from under sartorius to descend subcutaneously over the medial side of the knee joint. In the leg it accompanies the great saphenous vein and passes in front of the medial malleolus into the foot. It supplies the skin over the medial border of the leg and foot as far as the ball of the big toe. It gives off: Infrapatellar branch Medial cutaneous nerves 35 Fig. 4.2. The femoral nerve. Fig. 4.3. The lumbar plexus 4.1.2 Sacral part The sacral part is lower one of the lumbosacral plexus and consists of the ventral rami of the 4th and 5th lumbar nerves (!), and all ventral rami of sacral nerves together with ventral ramus of the coccygeal nerve. It lies on the pelvic surface of the sacrum in the front of the piriformis. Its branches are divided into groups: 1. Pelvic branches: a. Muscular branches to the piriformis, levattor ani, gemellus superior, inferior, quadratus femoris, obturator internus, coccygeus and the external anal sphincter. b. Pelvic splanchnicus nerves from the sacral parasympathetic part of the autonomic system, are derivation of the 2nd, 3rd, 4th sacral nerves. 36 2. Branches leaving the pelvis: a. Superior gluteal nerve leaves the pelvis above the piriformis and supplies the gluteus medius and minimus and the tensor fasciae latae. b. Inferior gluteal nerve leaves the pelvis below the piriformis and enters the substance of gluteus maximus and supplies this muscle. c. Pudendal nerve leaves the pelvis via the greater sciatic foramen. passes around the sciatic spine to the lesser sciatic foramen accompanies the internal pudendal vessels. It supplies sphincter ani externus and skin of the genitalia by posterior scrotal or labial branches (! see the origin of the anterior branches above). d. Posterior femoral cutaneous nerve of thigh emerges superficial to the sciatic nerve and descends in the midline of the thigh, beneath the deep fascia. It supplies the skin of the buttock, the perineum, the posterior aspect of the thigh and the popliteal region. It gives off: i. Inferior clunial nerves. 3. Perineal branches a. Nerve to quadratus femoris emerges deep to the sciatic nerve and lies on the ischium. It supplies its muscle, the inferior gemellus and the hip joint. b. Nerve to obturator internus descends across the ischial spine to supply its muscle and the superior gemellus. c. Sciatic nerve is the largest nerve in the body. It is derived from ventral rami L4,5;S1,2,3 and is formed in the pelvis on the anterior surface of piriformis. It emerges lateral to the ischial spine descending through the greater sciatic foramen, enters the gluteal region and continues its descent through the posterior compartment of the thigh, and ends by dividing into tibial and common peroneal nerves, usually just above the popliteal fossa. Relations of the sciatic nerve on entering the gluteal region: Below piriformis Medially: the inferior gluteal vessels and nerve. Anteriorly: the posterior cutaneous nerve of thigh posteriorly and the nerve to quadratus femoris between it and the ischium. Anteriorly the nerve lies on the ischium, obturator internus and the gemelli, quadratus femoris and adductor magnus from above downwards. Covered posteriorly by gluteus maximus and the hamstring muscles. Sciatic nerve gives off the following branches: 1. Articular: to the hip joint 2. Muscular: to the hamstrings and the ischial part of adductor magnus. 3. Tibial and common peroneal nerves 37 Fig. 4.4. Sacral plexus. Fig. 4.5. Skin innervation of the thigh 38 5 Vessels of the thigh 5.1 Femoral artery This is the continuation of the external iliac artery. It enters the thigh below the inguinal ligament descends vertically and slightly backwards through the femoral triangle and the subsartorial canal. It ends by piercing the adductor magnus about 10 cm above the knee joint. It then becomes the popliteal artery. Relations: 1. It begins deep to the inguinal ligament, halfway between the anterior superior iliac spine and the symphysis pubis (the midinguinal point). 2. In the femoral triangle it is covered only by fascia and descends on the psoas tendon (which separates it from the hip joint), pectineus and adductor longus from above downwards. 3. It leaves the triangle at its apex to enter the adductor canal in company with its vein, the saphenous nerve and the nerve to the vastus medialis. The canal is a narrow intermuscular passage deep to the middle third of sartorius. 4. It is bounded posteriorly by adductor longus above and adductor magnus below and anterolaterally by the vastus medialis. 5. It leaves the lower end of the canal by passing through an opening in adductor magnus. Above, the femoral vein lies medially to the artery, in the apex of the triangle and in most of the adductor canal it is located posteriorly, and in the lower part of the canal it is located laterally to the artery. 5.1.1 Femoral artery branches 1. 2. 3. 4. Superficial epigastric artery Superficial circumflex iliac artery Superficial external pudendal artery Deep external pudendal artery ( it subdivides into anterior labial and scrotal branches, inguinal branches) 5. Descending genicular artery (it subdivides into saphenous branch and articular branch) 6. Deep femoral artery and its big branches: arises in the femoral triangle and passes backwards between pectineus and adductor longus. It descends on adductor brevis and then magnus, and, just above the knee, pierces the latter muscle to supply the lower part of the back of the thigh. Its three main branches also pierce adductor magnus to supply the posterior part of the thigh. They are called perforating arteries. a. Medial circumflex femoral artery: passes posteriorly between pectineus and psoas to reach the upper border of adductor magnus where it divides into muscular and articular branches. It gives off: i. Superficial branch ii. Deep branch iii. Acetabular branch iv. Ascending branch v. Descending branch b. Lateral circumflex femoral artery: passes laterally between the branches of the femoral nerve, then deep to sartorius and: rectus femoris and gives off muscular and articular branches. It gives off: i. Ascending branch ii. Descending branch iii. Transverse branch c. Perforating arteries (of deep femoral artery). 39 5.1.2 Obturator artery The obturator artery, a branch of the internal iliac, accompanies the nerve through the obturator canal and on emerging, divides into two branches which encircle the obturator membrane. It gives branches to the hip joint and the adductor muscles. 5.1.3 Femoral vein This begins at the opening in the lower end of adductor magnus as the continuation of the popliteal vein. It accompanies the femoral artery and ends at the level of the inguinal ligament by becoming the external iliac vein. In its lower part it is located posterolateral to the artery but as it ascends it passes behind, and ends on its medial side. 5.1.3.1 Tributaries 1. Deep femoral vein. 2. Great saphenous vein pierces the cribriform fascia to enter the femoral vein about 3cm below the inguinal ligament. this vein has many tributaries on thigh: a. External pudendal veins b. Superficial circumflex iliac vein c. Superficial epigastric vein d. Accessory saphenous vein e. Superficial dorsal veins of penis (m) f. Superficial dorsal veins of clitoris (f) g. Anterior scrotal veins (m) h. Anterior labial veins (f) 3. Medial circumflex femoral vein 4. Lateral circumflex femoral vein 5. Small subcutaneous veins: draining the inguinal region enter the femoral vein at the termination of the saphenous vein. 6 Vessels of the gluteal region These are branches of the internal iliac artery. They pass from the pelvis to the gluteal region above or below the piriformis in the greater sciatic foramen. Above piriformis: Superior gluteal artery pass upwards and laterally between gluteus medius and minimus to supply these muscles and tensor fasciae latae. The artery takes part in an anastomosis around the hip joint. Below piriformis: Inferior gluteal artery ramifies in the lower part of the buttock and takes part in an anastomosis around the hip joint. Internal pudendal vessels and the pudendal nerve: descend over the ischial spine and sacrospinous ligament and pass through the lesser sciatic foramen into the perineum. 7 Fasciae 1. Iliac fascia covers the iliopsoas. When it passes below inguinal ligament it changes name into iliopectineal fascia and forms deep lamina of fascia lata. 2. Iliopectineal arch, which passes from inguinal ligament to iliopectineal eminence divides common space into muscular space and vascular space. 40 3. Fascia lata covers muscles of the thigh. It is especially strong on the lateral side because the iliotibial tract passes here. Iliotibial tract is tendinous, 6 cm wide band which origins from the tendinous fibres of tensor fascia lata, gluteus maximus and gluteus medius and ends on the lateral condyle of tibia. Fascia lata goes as one lamina from lateral side of thigh to the sartorius on to which it divides into the superficial and deep laminas, then in the medial direction it forms one lamina again and in 1/3 of upper anterior surface of the thigh divides into deep and superficial laminas again. Deep lamina is formed by iliopectineal fascia. The superficial lamina is called the cribriform fascia. Medially fascia lata becomes one lamina again. Fascia lata sends to the lateral and medial lips of linea aspera: the lateral femoral intermuscular septum and medial femoral intermuscular septum, which lie to the back from vastus lateralis and vastus medialis. 8 Topographical elements 8.1 Femoral triangle The femoral triangle is an area on the front of the upper part of the thigh. It is bounded by: 1. Inguinal ligament: superior limit 2. Sartorius: lateral limit 3. Medial border of the adductor longus: medial limit Its floor is formed from medial to lateral by the adductor longus, the pectineus and the iliopsoas. The fascia lata of the thigh is the roof. There is an oval deficiency, the saphenous opening, in the fascia lata about 3 cm below and lateral to the pubic tubercle. This opening has a well-defined lateral margin, and is filled by the cribriform fascia, a condensation of the superficial fascia. The opening is traversed by the great saphenous vein and some small cutaneous vessels. In the triangle are the femoral vessels contained within the femoral sheath and the femoral nerve and their branches. 8.1.1 Femoral sheath Femoral sheath is a tube-like downwards continuation of the extraperitoneal fascia into the thigh. It is formed anteriorly from the fascia transversalis and posteriorly from the iliac fascia. The femoral vessels evaginate the fascial envelope of the abdomen as they leave the cavity. Inferiorlly the sheath fuses with the adventitiae of the vessels about 3 cm below the inguinal ligament. Septa divide it into three compartments containing: 1. Femoral artery: laterally 2. Femoral vein: centrally 3. Femoral canal: with fatty connective tissue and lymph nodes medially It is limited by the blending of its medial wall with the adventitiae over the laterally placed femoral vein. Superiorly the canal communicates with the extraperitoneal abdominal fascial space by an opening, the femoral ring. The ring is bounded: 1. 2. 3. 4. Anteriorly: by the inguinal ligament Posteriorly: by the pubis Medially: by the pectineal part of the inguinal ligament Laterally: by the femoral vein These relations should be noted as herniation of abdominal contents into the femoral canal (femoral herniation) may occur and the femoral ring then provides a constriction around the hernial sac. During exercise, the femoral vein enlarges and is accommodated by the canal medially. 41 8.2 Adductor canal 1. Anterior wall is formed by anteromedial intermuscular septum and sartorius 2. Medial wall is formed by adductor magnus 3. Lateral wall is formed by vastus medialis Adductor canal contains: 1. Femoral artery 2. Femoral vein 3. Saphenous nerve 8.3 Muscular space 1. Anterior limit is made of inguinal ligament 2. Posterior limit is made of superior pubic ramus, iliopubic eminence, anterior superior iliac spine, anterior inferior iliac spine 3. Medial limit is made of iliopectineal arch This space contains: a. Iliopsoas b. Femoral nerve c. Lateral cutaneous nerve of thigh 8.4 Vascular space Anterior limit is formed by inguinal ligament Posterior limit is formed by pecten pubis Lateral limit is formed by iliopectineal arch Medial limit is formed by lacunar ligament. Vascular space contains: a. b. c. d. Femoral ring Femoral artery Femoral vein Femoral branch of genitofemoral nerve 8.5 Femoral canal It goes from femoral ring to saphenous opening. It is a place where femoral hernias origins. 1. 2. 3. 4. 5. Anterior limit of femoral ring is formed by inguinal ligament Posterior limit of femoral ring is formed by pectin pubis Lateral limit of femoral ring is formed by femoral vein Medial limit of femoral ring is formed by lacunar ligament Superior limit of femoral ring is formed by femoral septum Lateral limit of saphenous opening is formed by falciform margin Superior limit of saphenous opening is formed by superior horn Inferior limit of saphenous opening is formed by inferior horn. Anterior wall of femoral canal is formed by anterior lamina of fascia lata Posterior wall of femoral canal is formed by posterior lamina of fascia lata Lateral wall of femoral canal is formed by femoral vein. 9 Popliteal fossa The popliteal fossa is a diamond-shaped fossa behind the knee joint. 42 It is bounded: 1. 2. 3. 4. Superomedially by the semitendinosus and semimembranosus Superolaterally by the biceps femoris Inferiorly by the medial and lateral heads of gastrocnemius Laterally by D muscle. The roof of popliteal fossa is formed by thickened deep fascia lata, which is called here popliteal fascia. That deep fascia is additionally perforated by the small saphenous vein which empties into popliteal vein. Through the roof of popliteal fossa passes also the posterior cutaneous nerve of thigh which after continues inferiorly to supply upper part of the posterior surface of the leg. Its floor is formed from above downwards by the popliteal surface of the femur, the posterior surface of the articular capsule of the knee joint and the popliteus with fascia covering it. Fig. 9.1. Diagram of the popliteal fossa (PF). BF – biceps femoris, Smem – semimembranosus, Sten- semitendinosus, Glh- lateral head of gastrocnemius, Gmh- medial head of gastrocnemius The popliteal fossa contains the popliteal vessels (artery (deeper) and vein) and its branches, the tibial nerve and common fibular (peroneal) nerve and its branches, fatty tissue and the lymph nodes. Clinical comments: The Baker’s cyst is a synovial cyst located in the popliteal space. It is an aberrant accumulation of the fluid in articular cavity causing the pain and swelling in popliteal region. 10 Leg and dorsum of the foot The muscles of the leg are divided into anterior, lateral and posterior groups by the tibia, interosseous membrane, and anterior and posterior intermuscular septa which pass inwards from the thick investing deep fascia to the fibula. The anterior intermuscular septum passes to the anterior border of the fibula and separates the anterior (dorsiflexor) compartment from the lateral (peroneal) compartment. The posterior septum passes to the posterior border of the fibula and separates the lateral from the posterior (plantar flexor) compartment. 43 10.1 Anterior group of muscles 10.1.1 Tibialis anterior Origin: upper two-thirds of the lateral surface of the tibia and adjoining interosseous membrane, Insertion: the fibers converge on to a central tendon which descends in front of the ankle joint deep to the superior and inferior extensor retinacula to end of the medial surface of the medial cuneiform and of the base of the lst metatarsal bone. Action: dorsiflexion and inversion of the foot. Nerve supply: the deep peroneal nerve. Arterial supply: Branches of anterior tibial artery: Anterior and medial muscular branches; anterior tibial recurrent, dorsalis pedis and anterior medial malleolar arteries. Branches of posterior tibial artery: Medial malleolar and calcaneal arteries. 10.1.2 Extensor hallucis longus Origin: middle two-quarters of the anterior surface of the fibula and adjoining interosseous membrane. Insertion: its long tendon passes under the extensor retinacula, in front of the ankle joint and crosses the dorsum of the foot to reach the base of the distal phalanx of the great toe. Action: extension of the great toe and it assists in dorsiflexion of the foot Nerve supply: the deep peroneal nerve. Arterial supply: Anterior tibial artery. 10.1.3 Extensor digitorum longus Extensor digitorum longus Origin: upper two-thirds of the anterior surface of the fibula lateral to the attachment of extensor hallucis longus, and from the adjacent intermuscular septum. Insertion: above the ankle the muscle divides into four tendons which pass under the extensor retinacula. Diverging on the dorsum of the foot a tendon passes to each of the lateral four toes and is attached in a similar manner to extensor digitorum in the hand, i.e. there is a dorsal expansion which is attached to the dorsum of the middle and terminal phalanges. Action: extension of the toes and it assists in dorsiflexion of the foot Nerve supply: the deep peroneal nerve Arterial supply: Anterior tibial, fibular, anterior lateral malleolar, lateral tarsal, metatarsal, plantar, and digital arteries. 10.1.4 Fibularis tertius (peroneus tertius) The lower third of the anterior surface of the fibula gives attachment to a thin sheet of muscle, the peroneus tertius whose tendon descends under the extensor retinacula to the 5th metatarsal. It is a weak dorsiflexor and evertor of the foot. Origin: Medial surface (distal 1/3) of fibula, anterior surface of interosseous membrane, anterior intermuscular septum. 44 Insertion: Dorsal surface of base of metatarsal bone 5Action: dorsiflexion of the medial four toes. Action: Talocrural joint: Foot dorsiflexion; Subtalar joint: Foot eversion. Nerve supply: Deep fibular nerve. Arterial supply: Anterior lateral malleolar artery, lateral tarsal artery, metatarsal arteries, lateral plantar artery, digital arteries, arcuate artery. 10.1.5 Extensor digitorum brevis This is the only short muscle on the dorsum of the foot and pass under extensor digitorum longus. Origin: anterior part of the upper surface of the calcaneus, Insertion: the muscle divides into four small tendons which pass obliquely forwards to the medial four toes. The lst tendon is attached to the base of the proximal phalanx of the great toe, the remainder join the lateral side of the extensor tendons passing to the 2nd, 3rd, and 4th toes. Action: dorsiflexion of the medial four toes. Nerve supply: the deep peroneal nerve supplies all the muscles of this group. Arterial supply: Fibular artery, anterior tibial artery, dorsalis pedis artery. 10.1.6 Extensor retinaculum (superior and inferior) The extensor retinacula (sing. retinaculum) lie across the extensor tendons in the lower part of the leg and in front of the ankle joint. Superior extensor retinaculum is an ill-defined thickening of deep fascia stretching between the anterior borders of the tibia and fibula about 3 cm above the ankle joint. It covers, from medial to lateral, the tendons of tibialis anterior and extensor hallucis longus, the anterior tibial vessels and the deep peroneal nerve, and the tendons of extensor digitorum longus and peroneus tertius. Inferior extensor retinaculum is a thicker bifurcate structure extending medially from the anterior part of the upper surface of the calcaneus over the front of the ankle joint enclosing, beneath it, the tendons of peroneus tertius and extensor digitorum longus. It then divides into two limbs which cross the anterior tibial vessels and deep peroneal nerve and the tendons of extensor hallucis longus and tibialis anterior. The upper limb is attached to the medial malleolus and the lower curves around the medial border of the foot to blend with the plantar aponeurosis. 10.1.6.1 Synovial sheaths The synovial sheaths of the long extensor tendons lie deep to the inferior retinaculum, that of tibialis anterior extends proximally under the superior retinaculum. Extensor hallucis longus has its own sheath and there is a common sheath for extensor digitorum longus and peroneus tertius. 45 Fig. 10.1, Muscles of the anterior and lateral compartment of the leg. Clinical comments: The shin splints are seen in runners during anterior compartment hypertension induced by exercises. 10.2 Lateral (peroneal) group of muscles 10.2.1 Fibularis longus (peroneus longus) Origin: upper two-thirds of the lateral surface of the fibula. Insertion: Tendon descends behind the lateral malleolus, separated from it by the tendon of peroneus brevis and crosses the lateral surface of the calcaneus below the peroneal trochlea to reach the cuboid. It passes medially in the groove on the under surface of the cuboid and runs obliquely across the sole of the foot deep to the long plantar ligament to gain attachment to the lateral side of the base of lst metatarsal and the adjacent area of the medial cuneiform bone. Action: Talocrural joint: Foot plantar flexion;Subtalar joint: Foot eversion. It also supports longitudinal and transverse arches of foot. Nerve supply: Superficial peroneal nerve. Arterial supply: Fibular artery. 10.2.2 Fibularis brevis (Peroneus brevis) Origin: lower two-thirds of the lateral surface of the fibula. Insertion: the tendon lies anterior to that of peroneus longus. It passes behind the lateral malleolus, across the lateral surface of the calcaneus above the peroneal trochlea, to the tuberosity on the base of the 5th metatarsal. 46 Action: Both these muscles (brevis and longus) evert and possibly plantar flexion the foot. Peroneus longus also helps to maintain the lateral longitudinal arch of the foot. Nerve supply: Superficial peroneal nerve. Arterial supply: Anterior tibial artery. Clinical comments: An avulsion (chip) fracture of the tuberosity of 5th metatarsal bone where the fibularis brevis inserted into it may occur. Usually that injury takes place during inversion of the ankle. The tendons of both these muscles are bound down to the lateral malleolus and the side of the calcaneus by two condensations of deep fascia, the superior and inferior peroneal retinacula. The tendons are enclosed in a common synovial sheath which is prolonged over each tendon to its distal attachment. Fig. 10.2. Flow chart of the leg muscles and its innervations. 10.3 Posterior group of muscles – superficial subgroup 10.3.1 Gastrocnemius Gastrocnemius is the most superficial muscle in the calf. Origin: medial and lateral heads to the corresponding, femoral condyles. Insertion: the two bellies form the inferior boundaries of the popliteal fossa and unite to form a tendon which joins that of soleus in the lower calf to form the calcaneal tendon (Achille’s tendon) which is attached to the middle of the posterior surface of the calcaneus. A bursa and a pad of fat separate the tendon from the upper part of the calcaneal surface. Action: Talocrural joint: Foot plantar flexion; Knee joint: Leg flexion. Nerve supply: Tibial nerve. Arterial supply: Sural arteries. 10.3.2 Plantaris This vestigial muscle is attached above to the lower end of the lateral supracondylar line and by a long thin tendon below to the medial side of the tendo calcaneus. Origin: Lateral supracondylar line of femur, oblique popliteal ligament of knee. Insertion: Posterior surface of calcaneus (via calcaneal tendon) Action: Talocrural joint: Foot plantar flexionl Knee joint: Leg flexion. 47 Nerve supply: Tibial nerve. Arterial supply: Sural arteries; Superior lateral genicular artery. 10.3.3 Soleus Soleus lies deep to gastrocnemius. Origin: A continuous line from the upper part of the posterior surface and head of the fibula, a tendinous arch over the posterior tibial vessels and tibial nerve, and the soleal line on the tibia. Insertion: The tendon unites with that of gastrocnemius to.form the tendo calcaneus. Action: Both gastrocnemius and soleus are powerful plantar flexors of the foot and as such are important in both posture and locomotion, they flex knee joint and supinate foot Nerve supply: Branches from the tibial nerve supply the calf muscles. Arterial supply: Posterior tibial artery and vein. 10.4 Posterior group of muscles – deep subgroup Deep muscles comprise popliteus above the soleal attachment and the flexor digitorum longus, tibialis posterior and flexor hallucis longus from medial to lateral below soleus. 10.4.1 Popliteus It is a triangular muscle lies below the lower part of the knee joint. Origin: Tibial posterior surface of the tibia above the soleal line. Femoral the muscle converges on to a tendon which pierces the capsule of the knee joint to gain attachment to the pit below the lateral epicondyle. It also sends a slip to the lateral meniscus. The popliteal bursa lies between the muscle and the upper part of the tibia. Insertion: Posterior surface of proximal tibia. Action: lateral rotation of the femur on the tibia and retraction of the lateral meniscus. These two actions occur simultaneously in “unlocking” of the extended knee. The backward movement of the lateral femoral condyle is preceded by the retraction of the cartilage which thus avoids injury. Nerve supply: a branch from the tibial nerve. Arterial supply: Inferior medial and lateral genicular arteries (popliteal artery); posterior tibial recurrent artery; posterior tibial artery; nutrient artery of tibia. 10.4.2 Flexor digitorum longus Origin: medial side of the posterior surface of the tibia below the soleal line. Insertion: the tendon crosses over tibialis posterior and grooves the lower end of the tibia lateral to the tendon of tibialis posterior, before passing deep to the flexor retinaculum to enter the sole of the foot where it divides into four slips. These slips pass to the terminal phalanges of the lateral four toes (their attachment being similar to that of the tendons of flexor digitorum profundus in the hand). In the foot, the main tendon gives attachment to flexor accessorius and the four slips to the four lumbricals. Action: flexion of the interphalangeal and metatarsophalangeal joints. It is also a weak plantar flexor of the foot, it supinate and adduct foot Nerve supply: The tibial nerve. 48 Arterial supply: Posterior tibial artery. 10.4.3 Tibialis posterior Origin: posterior surface of the interosseus membrane and the adjoining surfaces of the tibia and fibula. Insertion: the tendon inclines medially deep to flexor digitorum longus, grooves the back of the medial malleolus, passes under the flexor retinaculum and then lies on the deltoid ligament. In the sole it is attached mainly to the tuberosity of the navicular but also to all other tarsal bones except the talus. Action: Inversion of the foot and helps to support the medial longitudinal arch Nerve supply: Tibial nerve. Arterial supply: Branches of the posterior tibial artery. 10.4.4 Flexor hallucis longus Origin: lower two-thirds of the posterior surface of the fibula. Insertion: the muscle becomes tendinous behind the lower end of the tibia where it lies lateral to the tendons of flexor digitorum longus and tibialis posterior. It grooves the back of the tibia and the talus and the under surface of the sustentaculum tali, and enters the sole. Here it is crossed over by the tendon of flexor digitorum longus and runs forwards between the two heads of the flexor hallucis brevis. It passes in the fibrous flexor sheath of the great toe to be attached to the plantar surface of the base of the distal phalanx. Action: powerful flexor of the great toe. It also helps in plantar flexion of the foot and is of importance in walking and m the maintenance of the medial longitudinal arch. Nerve supply: the tibial nerve. Arterial supply: Posterior tibial artery, fibular artery. Fig. 10.3. The flow chart of the muscles of posterior compartment of the leg and their action. 49 10.4.5 Flexor retinaculum The flexor retinaculum is a thickened band of deep fascia passing from the medial malleolus to the medial tubercle of the calcaneus. It overlies from medial to lateral, the tendons of tibialis posterior and flexor digitorum longus, posterior tibial vessels, tibial nerve and the flexor hallucis longus tendon. Each tendon is enclosed in a. separate synovial sheath, those of flexor hallucis longus and flexor digitorum longus passing into the sole of the foot. 10.4.6 Deep fascia of leg Deep fascia of leg covers all muscles of leg and is attached close to tibia on anterior surface. Fascia forms anterior and posterior intermuscular septums of leg which attach to anterior and posterior borders of fibula. They form three compartments for muscles – anterior one for extensors, lateral one for peroneus muscles and posterior one for flexors. Besides fascia forms on anterior surface superior and inferior extensor retinaculums, on lateral suface superior and inferior fibular retinaculums and on medial surface flexor retinaculum. 11 Vessels of the leg 11.1 Popliteal artery This is the continuation of the femoral artery. It descends from the opening in the adductor magnus to the lower border of popliteus where it ends by dividing into anterior and posterior tibial arteries. Relations: it descends on the floor of the popliteal fossa, deep to its vein which separates it throughout its course from the tibial nerve. 11.1.1 Branches of popliteal artery 1. 2. 3. 4. 5. 6. 7. Superior lateral genicular artery Superior medial genicular artery Middle genicular artery Sural arteries Inferior lateral genicular artery Inferior medial genicular artery Anterior tibial artery passes forwards above the interosseus membrane and accompanies the deep peroneal nerve in its descent through the extensor compartment of the leg. below the ankle joint it continues as the dorsalis pedis artery which passes forwards on the dorsum of the foot to reach the space between the lst and 2nd metatarsal bones. it enters the sole of the foot between these bones and anastamoses with the lateral plantar artery. branches of anterior tibial artery: a. Anterior tibial recurrent artery b. Posterior tibial recurrent artery c. Anterior lateral malleolar artery d. Anterior medial malleolar artery 8. Posterior tibial artery is also a terminal branch of the popliteal artery. it begins at the lower border of popliteus and descends through the flexor compartment of the leg with the tibial nerve. it ends behind the medial malleolus by dividing into medial and lateral plantar arteries. branches of posterior tibial artery: a. Circumflex fibular branch b. Medial malleolar branches c. Calcaneal branches d. Tibial nutrient artery 50 9. Fibular (peroneal) artery descends between the fibula and flexor hallucis longus. it gives off muscular branches and an articular branch to the ankle joint. branches of peroneal artery: a. Perforating branch b. Communicating branch c. Lateral malleolar branches d. Calcaneal branches e. Fibular nutrient artery 11.2 Popliteal vein This is formed by the union of the anterior and posterior tibial veins. Throughout its course it lies between the popliteal artery and tibial nerve. Its tributaries correspond mainly to the branches of the artery but the small saphenous vein enters it after piercing the fascial roof of the popliteal fossa. 12 Nerves of the leg 12.1 Tibial nerve This is a terminal branch of the sciatic nerve. It is formed just above the popliteal fossa and descends almost vertically through the fossa to pass deep to soleus. It descends through the flexor compartment of the leg to reach the back of the medial malleolus where it ends by dividing into medial and lateral plantar nerves. Relations (in the popliteal fossa) : superiorlly it is deep to semimembranosus and semitendinosus, inferiorlly, to the two heads of gastrocnemius. In most of its course it lies in the popliteal fat superficial to the popliteal vessels, the vein separating it from the artery. (In the calf) it descends deep to soleus, crossing to the lateral side of the posterior tibial vessels and lying between flexor digitorum longus medially and flexor hallucis longus laterally. It lies on tibialis posterior superiorlly and the capsule of the ankle joint inferiorlly and ends deep to the flexor retinaculum. 12.1.1 Branches of the tibial nerve 1. Interosseus nerve of leg 2. Medial sural cutaneous nerve, which after union with fibular communicating branch (halfway down the leg) from common fibular nerve changes name in sural nerve. It continues in company with the small saphenous vein behind the lateral malleolus and along the lateral side of the foot. It supplies the skin over the back of the leg, the ankle joint and the lateral border of the foot and 5th toe. 3. Articular branches: to the knee and superior tibiofibular joints. 4. Muscular branches: to the medial and lateral heads of gastrocnemius. plantaris, popliteus, soleus and the more deeply placed tibialis posterior, flexor hallucis longus and flexor digitorum longus. 5. Medial and lateral plantar nerves. 12.2 Common fibular nerve (common peroneal nerve) This also is a terminal branch of the sciatic nerve formed just above the popliteal fossa. It descends along the lateral margin of the fossa, and passes into peroneus longus where it divides into superficial and deep peroneal nerves. Relations: in its descent it lies on the lateral head of gastrocnemius and the neck of the fibula. It is overlapped by biceps in its upper course but it lies subcutaneously on the neck of the fibula. 51 12.2.1 Branches of the common fibular nerve 1. Fibular communicating nerve is cutaneous branch pierces the roof of the popliteal fossa and descends to join the medial sural cutaneous nerve and forms sural nerve halfway down the leg. 2. Lateral sural cutaneous nerve of the leg descends over the lateral head of gastrocnemius to supply the lateral aspect of the leg. 3. Articular branches to the knee and superior tibiofibular joints. 4. Superficial peroneal nerve is a terminal branch of the main trunk. It begins in the substance of peroneus longus and descends deep to this muscle, between it and peroneus brevis. In the lower part of the leg it emerges between peroneus brevis and peroneus tertius to divide into medial and lateral cutaneous branches which cross superficial to the extensor retinacula. It gives off following branches: a. Muscular branches: to peroneus longus and brevis b. Medial and intermediate dorsal cutaneous nerves: these descend over the extensor retinacula on to the dorsum of the foot and there divide into dorsal digital nerves. The medial branch supplies the medial side of the great toe and the 2nd interdigital cleft; the lateral branch supplies the 3rd and 4th interdigital clefts. 5. Deep peroneal nerve is also a terminal branch of the main trunk. It continues around the neck of the fibula, pierces the anterior intermuscular septum and then descends in the extensor compartment in company with the anterior tibial artery initially between extensor digitorum longus laterally and tibialis anterior medially and then between extensor hallucis longus laterally and tibialis anterior medially. At the ankle joint it passes under the extensor retinaculum lateral to the artery and divides into medial and lateral terminal branches. It gives off following branches: a. Muscular branches to the long extensor muscles. b. Lateral terminal branch passes deep to extensor digitorum brevis, supplying it and the ankle joint. c. Medial terminal branch continues on the dorsum of the foot lateral to the dorsalis pedis artery and supplies the skin of the 1st interdigital cleft. Clinical comments: The common fibular nerve is located superficially and it wrap up fibula. Injury of the common fibular nerve are common and the dorsiflexion of foot is impossible. That inability is known as foot drop. 13 Foot The foot has own short muscles divided into: 1. Muscles of the dorsum. 2. Muscles of the sole of foot (planta). The muscles which support the arches of foot during walking are: 1. Tibialis anterior. 2. Tibialis posterior. 3. Fibularis longus. 13.1 Dorsal muscles of the foot There are only two dorsal muscles of the foot: Extensor digitorum brevis and extensor hallucis brevis lie under tendons of the extensor digitorum longus muscle. Origin: Superior and lateral surfaces of the calcaneus. 52 Insertion: Toes (I-IV), four tendons fuse with the lateral margin of the extensor digitorum longus and the extensor hallucis longus. The 5th toe has the tendon from the peroneal tertius muscle. Action: Extends metatarsophalangeal joints. Nerve supply: Deep fibular nerve. Arterial supply: Fibular artery, anterior tibial artery, Dorsal artery of foot. Fig. 13.1. The flowchart of the superficial muscles of the foot and their innervations. 13.2 Plantar muscles of the foot The plantar muscles consists of three groups which are divided into four layers. The muscles of the sole of foot form the following groups: 13.2.1 Muscles of the medial eminence (muscles of 1st (great) toe) 13.2.1.1 Abductor hallucis Abductor hallucis (m. abductor hallucis) is the most superficial muscles on the medial margin of the planta. Origin: Medial tubercle of the calcaneus Insertion: Base of the proximal phalanx of the 1st toe Action: Abducts great toe Nerve supply: Medial plantar nerve. Arterial supply: Medial plantar and first plantar metatarsal arteries. 13.2.1.2 Flexor hallucis brevis Flexor hallucis brevis is medially beneath the abductor hallucis. Origin: Plantar surfaces all cuneiforms and cuboid bone Insertion: Base of the proximal phalanx of the 1st toe Action: Flexes proximal phalanx of the great toe Nerve supply: Medial plantar nerve 53 Arterial supply: First metatarsal artery (plantar arch); Superficial branch of the medial plantar artery (posterior tibial artery). 13.2.1.3 Adductor hallucis Adductor hallucis lies deeply and it consists of two heads (oblique & transverse). Origin: base of the metatarsal bones II-IV (oblique head); the metatarsophalangeal ligaments (transverse head). Insertion: base of the proximal phalanx of the 1st toe. Action: adducts great toe. Nerve supply: deep branch of the lateral plantar nerve. Arterial supply: Medial plantar artery, lateral plantar artery, plantar arch, plantar metatarsal arteries. 13.2.2 Muscles of the lateral eminence (muscles of the little toe) 13.2.2.1 Abductor digiti minimi Abductor digiti minimi lies on the lateral margin of the planta. Origin: Calcaneus. Insertion: Lateral side of the proximal phalanx of the 5th toe. Action: Adducts of the 5th toe. Nerve supply: Lateral plantar nerve. Arterial supply: Lateral plantar artery. 13.2.2.2 Flexor digiti minimi Flexor digiti minimi is a small muscle which lies beneath the abductor. Origin: the metacarpal bone. Insertion: the proximal phalanx of the 5th toe. Action: flexes of the 5th toe. Nerve supply: Lateral plantar nerve. Arterial supply: Arcuate, lateral tarsal and lateral plantar arteries. 13.2.2.3 Opponens digiti minimi Opponens digiti minimi is a small muscle which fuses with the flexor digiti minimi. Origin: Long plantar ligament Insertion: Lateral side of the 5th metatarsal bone Action: Braces up the lateral border of the plantar arch Nerve supply: Lateral plantar nerve Arterial supply: Arcuate, lateral tarsal and lateral plantar arteries. 13.2.3 Muscles of intermediate emimence There are four muscles of the intermediate eminence (muscles of the middle sole). 54 13.2.3.1 Flexor digitorum brevis Flexor digitorum brevis lies superficially beneath the plantar aponeurosis. Origin: tuberosity of the calcaneus Insertion: four tendons splits into two parts, on sides of the middle phalanges, between which the long flexor passes Action: flexes middle phalanges II-V Nerve supply: medial plantar nerve Arterial supply: Medial and lateral plantar arteries and plantar arch, plantar metatarsal and plantar digital arteries. 13.2.3.2 Quadratus plantae The quadratus plantae or flexor digitorum accessorius lies under the short flexor of the toe. Origin: Calcaneus Insertion: Tendon of the flexor digitorum longus Action: Flexes distal phalanges II-V Nerve supply: Lateral plantar nerve Arterial supply: Medial plantar artery, lateral plantar artery, deep plantar arterial arch. 13.2.3.3 Lumbrical muscles The lumbricals are four in number, small muscles similar to the lumbricals of the hand: Origin: the tendons of the flexor digitorum longus (medial side of it for 1st lumbrical) Insertion: medial sides of the phalanx II-V Action: flex proximal phalanges (MTP joint) and extend middle and distal phalanx (IP jpint) of the II-V toes Nerve supply: medial plantar nerve /1st lumbrical/ and lateral plantar nerve /2nd, 3rd, 4th lumbricals/. Arterial supply: Lateral plantar artery, plantar metatarsal arteries, dorsal metatarsal arteries, dorsal digital arteries. 13.2.3.4 Interossei muscles The interossei muscles (mm. interossei) are divided into two groups: 13.2.3.4.1 Dorsal interossei muscles Dorsal interossei muscles lie in the intermetacarpal spaces and there are four in number: Origin: between adjacent sides of the metatarsal bone Insertion: 1st and 2nd muscles to the sides of the II toe; 3rd and 4th muscles to the sides of the III and IV toes Action: abduct II through IV toes from the axis of II toe, flex in plantar direction Nerve supply: lateral plantar nerve Arterial supply: Arcuate artery, dorsal and plantar metatarsal arteries. 13.2.3.4.2 Plantar interossei muscles Plantar interossei muscles are three in number. 55 Origin: medial sides of III-V toe Insertion: medial sides of corresponding toe. Action: adduct III through V toes toward the II toe, flex in plantar direction. Nerve supply: lateral plantar nerve. Arterial supply: Lateral plantar artery. REMEMBER! All plantar muscles which are innervated by lateral plantar nerve! Mnemonic: Some Live For Hot And Happy Dancing Brunettes. Second toe Lumbrical Flexor Hallucis brevis Abductor Hallucis Flexor Digitorum Brevis Fig. 13.2. Muscles of the foot and it innervation. Short flexors, abductors, and adductor of the big toe, lumbrical and interosseous muscles are present but there is no opponens muscle. The small muscles help to maintain the arches and move the toes but have little abductor or adductor action. The flexor accessorius has no counterpart in the hand. It is attached to the calcaneus posteriorly and to the lateral side of the tendons of flexor digitorum longus and flexor hallucis longus anteriorly. Tension in the digital tendons and flexion of the toes can be maintained by accessorius when the long flexors have to relax. This occurs when the leg is being pulled forwards over the ankle joint by tibialis anterior and the extensor muscles during the supporting phase of walking. All the short muscles of the sole are supplied by the lateral plantar nerve except for abductor hallucis, flexor hallucis brevis, flexor digitorum brevis and the 1 st lumbrical which are supplied by the medial plantar nerve. 56 The long flexor tendons pass along the sole of the foot into the flexor tendon sheaths and are attached to the base of the terminal phalanges. The tendons of three large muscles are inserted close together on the medial side of the foot. The tendon of tibialis posterior is attached to the tuberosity of the navicular and then spreads out to all the other tarsal bones except the talus and to some metatarsal bases. The tendon of peroneus longus, having crossed the foot, is attached to the lateral side of the medial cuneiform and of the 1 st metatarsal base. The tendon of tibialis anterior is attached to the medial side of the same two bones. These three muscles are strong supporters of the arches of the foot. The plantar fascia consists of a thickened central portion, the plantar aponeurosis, and thin medial and lateral portions. The aponeurosis is attached posteriorly to the back of the under- surface of the calcaneus and divides anteriorly into five digital expansions. These are continuous with the fibrous flexor tendon sheaths along the plantar aspect of the toes, and are also attached to the ligaments binding together the heads of the metatarsals. When the toes are dorsiflexed, the plantar aponeurosis is tightened and the longitudinal arch is accentuated. There are transverse fasciculi and superficial transverse metatarsal ligaments between parts of plantar aponeurosis. There is dorsal fascia of foot on dorsal surface of foot. 14 Plantar vessels 14.1 Lateral plantar artery Lateral plantar artery is the larger terminal branch of the posterior tibial artery and arises deep to the flexor retinaculum. It runs in a superficial plane obliquely across the sole, to the base of the 5th metatarsal bone where it turns medially and passes deeply back across the foot to anastomose with the dorsal pedis artery in the 1 st metatarsal space, thus completing the deep plantar arch. Branches of lateral plantar artery: 1. Digital branch to lateral side of 5th toe. 2. From the plantar arch: four plantar metatarsal arteries. They pass distally and divide into common plantar digital arteries and then in proper plantar digital arteries supplying the sides of adjacent toes, and anastomose with the dorsal metatarsal branches of the dorsalis pedis artery by means of perforating branches which pass through the metatarsal spaces. 14.2 Medial plantar artery Medial plantar artery is the smaller terminal branch of the posterior tibial artery. It passes anteriorly to supply the medial side of the great toe and anastamoses with the medial three plantar metatarsal arteries. The veins accompany the arteries and anastomose with the dorsal venous arch. Branches: 1. Deep branch 2. Superficial branch 14.3 Dorsal artery of foot Dorsal artery of foot is distal branch of anterior tibial artery. It is artery which is usually checked during physical examination when we want to check peripheral circulation. It gives off following branches: 1. Lateral tarsal artery 2. Medial tarsal arteries 3. Arcuate artery, which subdivides into dorsal metatarsal arteries and form dorsal digital arteries; dorsal digital arteries by perforating branches connect with deep plantar arch. 4. Deep plantar artery 57 15 Plantar nerves 15.1 Lateral plantar nerve Lateral plantar nerve is the smaller terminal branch of the tibial nerve. It begins under cover of the flexor retinaculum and, accompanied by its artery, passes obliquely across the sole, to the base of the 5th metatarsal bone where it divides into deep and superficial branches. Branches: 1. Branches to the skin over the lateral side of the foot. 2. Superficial terminal branch gives muscular branches and common plantar digital nerves, which divide into proper plantar digital nerves to the lateral 1½ toes. 3. Deep terminal branch turns medially in company with the lateral plantar artery and supplies the small deep muscles. 15.2 Medial plantar nerve Medial plantar nerve begins under the flexor retinaculum and passes forwards accompanied by its vessels. It supplies some muscular branches and cutaneous branches to the medial part of the sole and the medial 3 ½ toes. Branches: 1. Muscular branches. 2. Common plantar digital nerves, which divide into proper plantar digital nerves. 16 Topographical elements 16.1 Medial malleolar canal Superior limit is formed by medial malleolus, malleolar groove. Lateral limit is formed by sustentaculum tali, body of talus. Medial limit is formed by flexor retinaculum. Contents: 1. 2. 3. 4. 5. 6. Tibialis posterior Flexor digitorum longus Posterior tibial artery Posterior tibial veins Tibial nerve Flexor hallucis longus Clinical comments: The tarsal tunnel is formed by the flexor retinaculum and extend posterior and inferior to medial malleolus. Compression in tarsal tunnel may lead to injury of tibial nerve. It resulting in weakness of the plantar muscles of the foot. From anterior to posterior it contains the: Tibialis posterior tendon Flexor Digitorum longus tendon Posterior tibial Artery Posterior tibial Vein 58 Tibial Nerve Flexor Hallucis longus tendon Mnemonic: Tom Dick And a Very Nervous Harry 16.2 Lateral malleolar canal Superior limit is formed by lateral malleolus, malleolar groove. Lateral limit is formed by superior and inferior fibular retinaculums. Medial limit is formed by lateral process of talus, fibular trochlea and groove for tendon of fibularis longus. Contents: 1. Fibularis longus 2. Fibularis brevis Clinical comments: On the lower limb the peripheral pulse may be felt at the following pulse points: 1. 2. 3. 4. Femoral artery Popliteal artery Posterior tibial artery Dorsalis pedis artery 59 17 Muscle actions Fig. 17.1. The muscles actions on the hip joint. 60 Fig. 17.2. The muscles actions on the knee joint. Fig. 17.3. The muscles actions on the ankle joint. 61 Fig. 17.4. The muscles actions on the transverse tarsal joint. Fig. 17.5. The muscles actions on the metatarsophalangeal and interphalangeal joint 62 18 MRI and CT images 1. Aorta 2. Common iliac artery 3. External iliac artery 4. Internal iliac artery 5. Femoral artery 6. Superior gluteal artery 7. Inferior gluteal artery 8. Superior vesical artery 9. Obturator artery 10. Iliolumbar artery 11. Pudendal internal artery 12. Medial circumflex femoral artery 13. Lateral circumflex femoral artery a. Ascending branch b. Horizontal branch c. Descending branch 14. Deep artery of thigh 63 64 65 66