Lower Limb Anatomy PDF

The Lower Limb  Skeleton of the Lower Limb Two separate regions 1. A single pelvic girdle (2 bones) 2. The free part (30 bones)  Pelvic (Hip) Girdle Each coxal (hip) bone consists of three bones that fuse together: ilium, pubis, and ischium The two coxal bones are joined ante...

The Lower Limb  Skeleton of the Lower Limb Two separate regions 1. A single pelvic girdle (2 bones) 2. The free part (30 bones)  Pelvic (Hip) Girdle Each coxal (hip) bone consists of three bones that fuse together: ilium, pubis, and ischium The two coxal bones are joined anteriorly by the pubic symphysis (fibrocartilage) Joined posteriorly by the sacrum forming the sacroiliac joints  The Ilium Largest of the three fused hip bones Superior part of the hip bone Consists of a superior ala and inferior body Body forms the acetabulum (the socket for the head of the femur) Superior border - iliac crest Hip pointer - occurs at anterior superior iliac spine Greater sciatic notch - allows passage of sciatic nerve  Ischium and Pubis Ischium - inferior and posterior part of the hip bone Most prominent feature is the ischial tuberosity: the part that meets the chair when you are sitting Pubis - inferior and anterior part of the hip bone Superior and inferior rami Body  Skeleton of the Thigh - Femur Longest, heaviest, and strongest bone in the body Proximally, the head articulates with the acetabulum of the hip bone forming the hip (coxal) joint Neck - distal to head, common site of fracture Distally, the medial and lateral condyles articulate with the condyles of the tibia forming the knee joint Also articulates with patella Femur  Femur Greater and lesser trochanters are projections where large muscles attach Intertrochanteric line – anterior Intertrochanteric crest – posterior Gluteal tuberosity and linea aspera - attachment sites for the large hip muscles Intercondylar fossa - depression between the condyles Medial and lateral epicondyles - muscle site attachments for the knee muscles Femur Femur  Patella Largest sesamoid bone in the body Forms the patellofemoral joint Superior surface is the base Inferior, narrower surface is the apex Thick articular cartilage lines the posterior surface Increases the leverage of the quadriceps femoris muscle Patellofemoral stress syndrome - “runner’s knee” Patella  Tibia (shin bone) The larger, medial weight-bearing bone of the leg The lateral and medial condyles at the proximal end articulate with the femur It articulates distally with the talus and fibula Tibial tuberosity - attachment site for the patellar ligament Medial malleolus - medial surface of distal end (medial surface of ankle joint)  Fibula The smaller, laterally placed bone of the leg Non-weight bearing The head forms the proximal tibiofibular joint Lateral malleolus - distal end, articulates with the tibia and the talus at the ankle Tibia and Fibula Tibia and Fibula  Skeleton of the Foot - Tarsals, Metatarsals, and Phalanges Seven tarsal bones - Talus: articulates with tibia and fibula - Calcaneus: the heel bone, the largest and strongest - Navicular - medial - Cuboid - lateral - Three cuneiforms – middle to lateral  The foot Five metatarsals - (I-V) base, shaft, head 14 phalanges (big toe is the hallux) Tarsus = ankle Ankle joint – talocrural joint  Veins of the lower limb Superficial veins: Near the surface - Great saphenous vein (empties into femoral) - Small saphenous vein (empties into popliteal vein) Deep veins: Accompany arteries (same names!) - Profunda femoris - Femoral - Popliteal - Anterior tibial - Posterior tibial - Fibular  Arteries of the lower limb Artery Supply Femoral (from external iliac) - Anterior and medial thigh Profunda femoris – deep artery of thigh - Muscles of medial, posterior and anterior compartments Lateral and medial circumflex femoral - Gluteal region, head and neck of femur (encircle the head of the femur) Obturator (from internal iliac) - Obturator muscles, adductors Popliteal - Knee, hamstrings and posterior compartment of the leg Anterior tibial - Anterior compartment of leg Posterior tibial - Posterior and lateral compartments leg Fibular - Posterior and lateral compartments leg Dorsalis pedis (dorsal artery of the foot) Foot  Nerves of the lower limb Nerve Roots Supply (motor only) Femoral nerve L2-L4 Anterior thigh Obturator nerve L2-L4 Medial thigh Inferior gluteal nerve L5, S1, S2 Glut max, superior hamstrings Superior gluteal nerve L4, L5, S1 Gluteus medius, minimus and tensor fascia latae Sciatic nerve L4-S3 Posterior thigh Tibial nerve L4-S3 Posterior compartment of the leg Common fibular nerve (Sciatic) L4,5,S1,2 Knee joint Superficial fibular L4,5,S1 Lateral compartment of the leg Deep fibular L5,S1,2 Anterior compartment of the leg  Femoral triangle and Adductor Canal Triangle: Anterior and superior thigh Contains many important structures: - Femoral nerve - Femoral artery - Femoral vein - Lymph nodes Adductor canal: from femoral triangle to the adductor hiatus in the tendon of adductor magnus – passage for femoral artery and vein  Adductor Hiatus Opening between the adductor and hamstring parts of the adductor magnus Allows the femoral artery and vein to pass from the anterior compartment to the popliteal fossa (posterior to the knee)  Popliteal fossa Diamond shaped space behind the knee All important vessels from the thigh to the leg pass through here: Popliteal artery and vein Small saphenous vein Tibial and common fibular nerves  Lower Limb Muscles Lower limb muscles function in stability, locomotion, and maintenance of posture. In contrast, upper limb muscles are characterized by versatility of movement. Muscles of the lower limbs often cross two joints and can act equally on both. Most muscles that move the femur originate on the pelvic girdle and insert on the femur. Most muscles that move the leg originate on the pelvic girdle/femur and insert on the tibia/fibula  Compartments Deep fascia separate muscles that act on the femur – Gluteal compartment: extend, laterally rotate, medially rotate and abduct the hip joint. – medial (adductor) compartment of the thigh adduct the femur at the hip joint. – anterior (extensor) compartment of the thigh extend the knee (and flex the hip). – posterior (flexor) compartment of the thigh flex the knee (and extend the hip).  What muscles are in each compartment? Gluteal Medial Anterior Posterior compartment Compartment Compartment Compartment Gluteus maximus Adductor magnus Rectus femoris Biceps Femoris Gluteus medius Adductor longus Vastus lateralis Semimembranosus Gluteus minimus Adductor brevis Vastus medialis Semitendinosus Tensor fascia latae Gracilis Vastus Piriformis Pectineus intermedius Sartorius  Gluteus Maximus O: iliac crest of coxal bone, sacrum & coccyx Insertions: - upper ~1/4 into gluteal tuberosity (a lateral ridge of the upper part of linea aspera) of femur - lower ~3/4 into iliotibial tract (a vertical band of connective tissue that attaches to the lateral condyle of the tibia) A: extends and rotates thigh laterally at the hip joint Innervation: Inferior gluteal nerve  Gluteus medius and minimus Gluteus medius O: ilium of coxal bone (under maximus) I: greater trochanter of femur A: abducts and rotates thigh medially (anterior fibres) and posteriorally (posterior fibres) at the hip joint Innervation: superior gluteal nerve Gluteus minimus O: ilium of coxal bone (under medius) I: greater trochanter of femur A: abducts and rotates thigh medially at the hip joint Innervation: superior gluteal nerve  Tensor Fasciae Latae O: iliac crest of coxal bone I: iliotibial tract (which attaches to the lateral condyle of the tibia) A: flexes and abducts thigh at the hip joint Innervation: superior gluteal nerve  Piriformis O: Sacrum I: Greater trochanter Action: Laterally rotates hip and abducts thigh Innervation: Anterior rami of S1 and S2  Medial Compartment of Thigh Adductor longus Adductor brevis Adductor magnus Pectineus Gracilis  Adductor Group Adductor longus O: Body of Pubis of coxal bone I: linea aspera of femur A: adducts and flexes thigh at the hip joint Innervation: Obturator nerve Adductor brevis O: inferior pubic ramus of coxal bone I: linea aspera of femur A: adducts and flexes thigh at the hip joint Innervation: Obturator nerve  Adductor Magnus O: ischiopubic ramus & ischial tuberosity of coxal bone I: linea aspera & adductor tubercle of femur A: adducts thigh at the hip joint - anterior (adductor) part flexes thigh at the hip joint - Posterior (hamstring) part extends thigh at the hip joint Innervation: Adductor part: Obturator Hamstring part: sciatic nerve  Pectineus and Gracilis Pectineus O: superior pubic ramus of coxal bone I: pectineal line (located between lesser trochanter and linea aspera) of femur A: flexes and adducts thigh at the hip joint Innervation: femoral nerve Gracilis O: pubic body and inferior pubic ramus of coxal bone I: superior medial surface of shaft of tibia A: adducts and medially rotates thigh at hip joint; flexes leg at knee joint Innervation: obturator nerve  Anterior compartment of thigh Also known as quadriceps femoris as a group Act on both knee (leg) and hip (thigh) Rectus femoris Vastus lateralis Vastus intermedius Vastus medialis Sartorius  Rectus femoris O: anterior inferior iliac spine of coxal bone I: upper border of patella ↓ patellar ligament ↓ tibial tuberosity of tibia A: flexes thigh at the hip joint and extends leg at the knee joint Innervation: femoral nerve  Vastus muscles Vastus lateralis O: greater trochanter & linea aspera of femur I: patella → patellar ligament → tibial tuberosity of tibia A: extend leg at the knee joint Innervation: femoral nerve Vastus medialis O: linea aspera of femur I: patella → patellar ligament → tibial tuberosity A: extend leg at the knee joint Innervation: femoral nerve Vastus intermedius O: anterior & lateral surfaces of shaft of femur I: patella → patellar ligament → tibial tuberosity A: extend leg at the knee joint Innervation: femoral nerve  Sartorius O: anterior superior iliac spine I: superior medial surface of shaft of tibia A: flexes leg at knee joint; flexes, laterally rotates and abducts thigh at hip joint note: this combination of movements places one foot onto the opposite knee, (i.e., the tailor’s sitting position) “tailor’s muscle” longest muscle in the body Innervation: Femoral nerve  Posterior Compartment of Thigh Otherwise known as hamstring muscles Act on both knee (leg) and hip (thigh) Biceps Femoris Semimembranosus Semitendinosus  Biceps Femoris O: long head: ischial tuberosity of coxal bone short head: linea aspera of femur I: head of fibula & lateral condyle of tibia A: flexes leg at knee joint and extends thigh at hip joint ** Two joint muscle Innervation: Long head – tibial division of sciatic nerve Short head – fibular division of sciatic nerve  Semimembranosus and Semitendinosus Semitendinosus O: ischial tuberosity of coxal bone I: superior medial surface of shaft of tibia A: flexes leg at knee joint and extends thigh at hip joint Innervation: tibial division of sciatic nerve Semimembranosus O: ischial tuberosity of coxal bone I: medial condyle of tibia A: flexes leg at knee joint and extends thigh at hip joint Innervation: tibial division of sciatic nerve  Muscles that move the foot and toes Divided into three compartments Anterior leg (dorsi flex, deep fibular): tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius Lateral leg (evert and plantar flex, superficial fibular): fibularis longus, fibularis brevis Posterior leg (plantar flex, tibial): gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, flexor hallucis longus  Anterior Compartment Tibialis Anterior O: lateral condyle & superior 2/3 of shaft of tibia and interosseous membrane I: 1st cuneiform & 1st metatarsal A: dorsiflexes foot at ankle joint & inverts foot at intertarsal joints Innervation: deep fibular nerve  Anterior Compartment Extensor Hallucis Longus O: mid-anterior surface of fibula and interosseous membrane I: distal phalanx of great toe A: extends the great toe & dorsiflexes foot at ankle joint Innervation: deep fibular nerve  Anterior Compartment Extensor Digitorum Longus O: lateral condyle of tibia, anterior surface of fibula and interosseous membrane I: branches to insert onto middle & distal phalanges of toes 2-5 A: extends toes 2-5 & dorsiflexes foot at ankle joint Innervation: deep fibular nerve  Anterior Compartment Fibularis tertius O: distal anterior 1/3 of fibula and interosseous membrane I: base of 5th metatarsal A: dorsiflexes foot at ankle joint & everts foot at intertarsal joints Innervation: deep fibular nerve  Lateral Compartment Fibularis Longus O: head & lateral surface of shaft of fibula and lateral condyle of tibia I: 1st cuneiform & 1st metatarsal A: plantar flexes foot at ankle joint & everts foot at intertarsal joints Innervation: superficial fibular nerve  Lateral compartment Fibularis Brevis O: distal lateral surface of shaft of fibula I: base of 5th metatarsal A: plantar flexes foot at ankle joint & everts foot at intertarsal joints Innervation: superficial fibular nerve  Superficial Posterior Compartment Gastrocnemius O: lateral & medial condyles of femur & articular capsule of knee I: calcaneus via the calcaneal (Achilles) tendon A: plantar flexes foot at ankle joint & flexes leg at knee joint Innervation: tibial nerve  Superficial Posterior Compartment Soleus O:head of fibula & shaft of tibia and soleal line I: calcaneus via the calcaneal (Achilles) tendon A: plantar flexes foot at ankle joint Innervation: tibial nerve  Deep posterior compartment: Tom, Dick and Harry (All Tibial Nerve) Tibialis posterior (TOM) O: tibia, fibula & interosseous membrane I: navicular, cuboid, all 3 cuneiforms, 2nd, 3rd & 4th metatarsals A: plantar flexes foot at ankle joint & inverts foot at intertarsal joints Flexor digitorum longus (DICK) O: posterior surface of shaft of tibia I: branches to insert onto distal phalanges of toes 2-5 A: flexes toes 2-5 & plantar flexes foot at ankle joint Flexor hallucis longus (HARRY) O: posterior inferior 2/3 of shaft of fibula I: distal phalanx of great toe A: flexes great toe & plantar flexes foot at ankle joint  Tom Dick Harry Muscle Group Muscles Joint (s) Action (s) Nerve (s) Gluteal Tensor fascia latae; gluteus Hip Hip abduction, hip Inferior gluteal; maximus; gluteus medius; gluteus extension; hip lateral superior gluteal; minimus; piriformis rotation; hip medial anterior rami of S1-2 rotation Anterior thigh Rectus femoris; vastus lateralis; Hip; knee Knee extension; hip Femoral vastum medialis; vastus flexion; abduction; intermedius; sartorius lateral rotation Medial thigh Adductor magnus; adductor longus; Hip; knee Adduct hip; knee Obturator; sciatic; adductor brevis; gracilis; pectineus flexion; medial femoral rotation; extend hip Posterior thigh Biceps femoris; semimembranosus; Hip; knee Extend hip; flex knee Sciatic – tibial semitendinosus Anterior leg Tibialis anterior; extensor hallucis Ankle; foot Dorsi flexion; Deep fibular longus; extensor digitorum longus; inversion; extension fibularis tertius of the toes Lateral leg Fibularis longus; fibularis brevis Ankle Eversion; plantar Superficial fibular flexion nerve Superficial Gastrocnemius; soleus Knee; ankle Plantar flexion; knee Tibial posterior leg flexion Deep posterior leg Tibialis posterior; flexor hallucis Ankle; foot Inversion; plantar Tibial longus; flexor digitorum longus flexion; flexion of toes Muscle Group Muscles Joint (s) Action (s) Nerve (s) Gluteal Gluteus maximus; gluteus medius; Hip Hip abduction; hip Inferior gluteal gluteus minimus; tensor fascia latae; flexion; hip Superior gluteal piriformis extension; medial Rami S1, S2 and lateral rotation Anterior thigh Sartorius; rectus femoris; vastus Hip; knee Knee extension; hip Femoral lateralis; vastus medialis; vastus flexion; abduction; intermedius lateral rotation Medial thigh Gracilis; adductor magnus; Hip; knee Adduction; hip Obturator; femoral; pectineus; adductor longus; flexion, hip sciatic adductor brevis extension; medial rotation of hip; knee flexion Posterior thigh Biceps femoris; semitendinosus; Hip; knee Knee flexion; hip Tibial branch of semimebranosus extension sciatic Anterior leg Tibialis anterior; extensor hallucis Ankle; foot Dorsi flexion; Deep fibular nerve longus; extensor digitorum longus; inversion; eversion fibularis tertius Lateral leg Fibularis longus; fibularlis brevis Ankle Plantar flexion; Superficial fibular eversion nerve Superficial Soleus; gastroc Ankle; knee Plantar flexion; knee Tibial posterior leg flexion Deep posterior leg Tibialis posterior; Flexor digitorum Ankle, tarsals, Plantar flexion; Tibial longus; Flexor hallucis longus foot inversion; flexion of toes Surface Anatomy of the Lower Limb  Joints of the lower limb: Self Study Review the following joints of the lower limb Review the type of joint, the movement produced at the joint, and ligaments listed for that joint: Hip joint Ligaments: Iliofemoral, ischiofemoral, pubofemoral, sacrospinous, sacrotuberous Knee joint Ligaments: Anterior cruciate, posterior cruciate, fibular collateral, tibial collateral, lateral meniscus, medial meniscus Ankle joint (talocrural) Ligaments: Anterior tibiofibular, posterior tibiofibular, anterior talofibular, posterior talofibular, calcaneofibular, medial ligament of the ankle (deltoid ligament), spring ligament.