Lower Limbs: Muscle and Fascia PDF - Anatomy Lecture Notes

ANATOMY-LEC: LE 2 | TRANS 3 Lower Limbs: Muscle and Fascia IDELFA S. ELEVAZO, M.D.| Lecture Date (09/16/2024) OUTLINE movements rather than as individual I. Lo...

ANATOMY-LEC: LE 2 | TRANS 3 Lower Limbs: Muscle and Fascia IDELFA S. ELEVAZO, M.D.| Lecture Date (09/16/2024) OUTLINE movements rather than as individual I. Lower Limbs B. Bursa muscles and the principal attachments. A. Functions C. Knee Conditions B. Regions of the D. Popliteal Fossa I. LOWER LIMBS Lower Limbs V. Leg Region A. FUNCTIONS OF LOWER LIMBS C. Fascia of the A. Fascial To support body weight Lower Limbs Compartment of To enable the individual to move from one place to another II. Gluteal Region the Leg (locomotion) A. Lateral Femoral Muscles B. Muscle of the Leg Region To help adapt to gravity 📋 To maintain body balance (equilibrium) B. REGIONS OF THE LOWER LIMBS 📖 B. Muscles of the VI. Ankle Region Gluteal A. Talocrural/Ankle Gluteal Region C. Joints of the Joint → is the prominent area posterior to the pelvis and gluteal region VII. Foot Region inferior to the level of the iliac crests (the buttocks). D. Ligaments of the A. Skin and Fascia → extending laterally to the posterior margin of the greater Gluteal Region B. Muscles of the trochanter. III. Femoral Region Foot → two parts of the lower limbs: A. Fascia of the C. Fascial ▪ Hip Region: overlies the greater trochanter laterally, Femoral Region Compartments of extending anteriorly to the ASIS B. Subfascial the Foot ▪ Buttocks spaces of the D. Arches of the Foot Femoral Femoral Region E. Ligaments → is the region of the free lower limb that lies between C. Muscles of the VIII. Physical Examinations the gluteal, abdominal, and perineal regions proximally, Femoral Region IX. Review Questions and the knee region distally. It includes most of the IV. Knee Region X. Formative Quiz femur (thigh bone). A. Knee Joint XI. References → The transition from the trunk to the free lower limb XII. Appendix occurs abruptly in the inguinal region (groin). → The boundary between the abdominal and perineal SUMMARY OF ABBREVIATIONS regions and the femoral region is demarcated by the ASIS Anterior Superior Iliac Spine inguinal ligament anteriorly and the ischiopubic PSIS Posterior Superior Iliac Spine ramus of the hip bone (part of the pelvic girdle or FHL Flexor Hallucis Longus skeleton of the pelvis) medially. FDL: Flexor Digitorum Longus Knee → includes the prominences (condyles) of the distal ❗️ Must know 📣 Lecturer 📖 Book 📋 Previous Trans femur and proximal tibia, head of the fibula, and patella (knee cap, which lies anterior to the distal end of LEARNING OBJECTIVES the femur), as well as the joints between these bony At the end of the lecture, the student should be able to structures. analyze the movements of the lower limbs based on → The posterior region of the knee (L. poples) includes a ✔ Position of the joints well-defined, fat-filled hollow, transmitting neurovascular ✔ Different muscle groups involved and their fascial structures, called the popliteal fossa. disposition Leg ✔ Specific action of each muscle group/compartment → is the part that lies between the knee and the narrow, ✔ The student should demonstrate knowledge and distal part of the leg. understanding of the fascia and musculature of the → It includes most of the tibia (shin bone) and fibula lower limbs by: (calf bone). o Describing the fascial disposition and → The leg (L. crus) connects the knee and foot. Often, specializations of the deep fascia and laypersons refer incorrectly to the entire lower limb as subsequent functional compartmentalization “the leg”. of muscle groups in specific regions of the Ankle/Talocrural lower limbs. → includes the medial and lateral prominences (malleoli) o Describing the femoral triangle, adductor that flank the ankle (talocrural) joint. canal, popliteal fossa, and the other fascial Foot spaces in the foot as to their boundaries and → is the distal part of the lower limb containing the contents. tarsus, metatarsus, and phalanges (toe bones). The o Describing the existence of bursae at the hip toes are the digits of the foot. and known regions. → The great toe (L. hallux), like the thumb, has only two o Identifying the main muscles of the lower phalanges (digital bones); the other digits have three. limbs conceived as functional groups in each region with respect to the principal joint LE 2 TRANS 3 TG-A1: I. Salinas, A. Sallan, N. Sampang, *T. San Andres, R. TE: J. E. Salongsongan, J. AVPAA: S.Y. Tan Page 1 of 35 Sandoval, G. Santiago E. Santiago  C. FASCIA OF THE LOWER LIMBS 📣 The gluteus maximus can be traced to its origins from the ilium, sacrum, coccyx, and partly from the ischium, and it SUPERFICIAL FASCIA The subcutaneous tissue corresponds to the superficial inserts at the greater trochanter and into the iliotibial tract. fascia and is made up of loose connective tissue with → The iliotibial tract is a lateral thickening of the fascia lata varying amounts of fat, cutaneous nerves, superficial and receives fibers from the tensor fasciae latae and veins, lymphatic vessels, and lymph nodes. gluteus maximus muscles. → This tract extends from the iliac tubercle down to the DEEP FASCIA anterolateral tibial tubercle, which corresponds to 📣 It can be appreciated after removal of the skin and Gerdy’s tubercle. subcutaneous tissue. The gluteus maximus is the largest muscle and serves It is a whitish sheath that invests the limb like a stocking. as the chief lateral rotator and extensor of the thigh at the It makes muscle contraction more efficient in returning hip joint. blood back to the heart → It’s important to note that you don’t sit on the gluteus It is named as follows: maximus when seated; rather, your hips flex at the hip → Gluteal fascia: gluteal region joint. → Fascia Lata: thigh → The inferior fibers of the gluteus maximus direct → Crural fascia: leg superiorly toward the ischial tuberosity. → Dorsal fascia, foot: Dorsum of the foot → When sitting, a person is actually resting on the ischial → Plantar fascia: Sole of the foot tuberosity, which is located between the skin and the - 📣 It thickens to form aponeuroses and retinacula. On the plantar aspect of the foot, or the sole of the foot, there are derivatives of the deep fascia of 📣 fascia, not on the gluteus maximus. Most of the muscles mentioned insert at or near the greater trochanter, and they primarily function as lateral the plantar fascia, namely the plantar aponeurosis, rotators of the thigh, with the exception of the gluteus the lateral and medial plantar fasciae, as well as the medius and gluteus minimus muscles, which, along with the interosseous fasciae. These structures divide the tensor fasciae latae, act as abductors and medial rotators of plantar aspect of the foot into four compartments. 📣 the thigh. The piriformis muscle is an important landmark in the gluteal region, as blood vessels and nerves are named based on their relation to it. → The superior gluteal vessels and nerves emerge above the piriformis muscle, while the inferior gluteal vessels and nerves emerge below it. → Other structures that emerge below the piriformis include the posterior femoral cutaneous nerve and the sciatic nerve, the latter being the most significant nerve supplying the lower limb. A. LATERAL FEMORAL MUSCLES Figure 1. Deep Fascia[Moore] It sends inward extensions called intermuscular septae separating muscles with similar functions, arterial & nerve supply, and venous drainage into compartments. II. GLUTEAL REGION 📣 The muscles that make up the gluteal region includes the gluteus maximus muscle. → If cut through the gluteus maximus, it will expose the gluteus medius muscle. → Further dissection will reveal the gluteus minimus Figure 2. Lateral Femoral Muscles[Netter] muscle. → Inferior to the gluteus minimus is the piriformis muscle, 📣 The Gluteal muscles are found in the gluteal region, → 📣 These includes the Gluteus maximus, Gluteus which is part of the triceps coxae, consisting of the covered by gluteal fascia. superior gemellus, obturator internus, and inferior gemellus muscles. medius, Gluteus minimus, Piriformis, Superior and → Below the triceps coxae is the quadratus femoris inferior gemelli, Obturator internus, Quadratus Femoris, muscle. Additionally, the tensor fasciae latae muscle is located at the anterolateral aspect of the thigh; it → 📣 and the Tensor Fascia Latae. Almost all gluteal muscles insert around or within the vicinity of the greater trochanter of the femur. actually marks the beginning of the muscles in the gluteal region. ANATOMY Lower Limbs: Muscle and Fascia Page 2 of 35  → 📋 All gluteal muscles are lateral rotators of the thigh except for gluteus medius, gluteus minimus and tensor lateral condyle of tibia; Some fibers insert on fascia latae. gluteal tuberosity of Femur ▪ These three are medial rotators and abductors of the Nerve Inferior gluteal nerve (L5, thigh S1, S2) Extensor and lateral Action B. MUSCLES OF THE GLUTEAL REGION rotation of the thigh 📋 Muscles of the gluteal region share a common GLUTEUS MEDIUS AND GLUTEUS MINIMUS 📣 compartment that is organized into two layers, namely, superficial and deep: → The gluteus medius, the gluteus minimus as well as → Superficial group of larger muscles the Tensor Fasciae Latae are medial rotators and ▪ Femoral artery abductors of the thigh and are innervated by the ▪ Mainly extensors, abductors, and medial rotators of thigh ▪ Includes: Gluteus Maximus, Gluteus Medius, Gluteus → 📣 superior gluteal nerve. The gluteus medius and the gluteus minimus keep the pelvis level when the weight of the body is on one Minimus and the Tensor Fascia Latae → Deep group of smaller muscles ▪ Mainly lateral rotators of the thigh → 📣 leg. The gluteus medius and the gluteus minimus contract on the supported side when standing on one ▪ Works with the strong ligaments of the hip joint to leg to prevent tilting of the pelvis on the unsupported steady the femoral head in the acetabulum ▪ Includes: Piriformis, Obturator Internus, Gemellus → 📋 side. The Gluteus Medius is cut to reveal the Gluteus Superior and Inferior and Quadratus Femoris → 📋 Minimus The Gluteus Minimus is the deepest and smallest of the superficial gluteal muscle Table 2. OINA of the Gluteus Medius External surface of ilium Proximal Attachment between the anterior and posterior gluteal lines Lateral surface of the Distal Attachment greater trochanter of the femur Superior Gluteal nerve (L5 Nerve and S1) Abduction and medial Action rotation of the thigh Table 3. OINA of the Gluteus Minimus Figure 3. Gluteus Maximus muscles [Netter] External surface of the → 📣📣 Gluteus maximus - extensor and Lateral rotator of the thigh The most superficial of all gluteal muscles. Proximal Attachment ilium between the anterior and inferior gluteal lines → → → 📣📋 The largest and heaviest muscle in the body. Innervated by the inferior gluteal nerve Covers all the other gluteal muscles except for the Distal Attachment Anterior surface of the greater trochanter of the femur 📋 anterosuperior third of the gluteus medius Gluteal Bursae: → Membranous sacs lined by a synovial membrane Nerve Superior gluteal nerve (L4 and S1) Abduction and medial containing a capillary layer of slippery fluid resembling Action rotation of the thigh egg white. → Separates the gluteus maximus from its adjacent PIRIFORMIS structures → Found in areas subject to friction to reduce it, and permit free movement 📣 Nice to Know We do not sit on the gluteus maximus muscle but rather the fatty fibrous tissue and the ischial bursa 📣 between the ischial tuberosity and the skin. When the thigh is flexed, the inferior portion of the gluteus maximus moves superiorly, leaving the ischial tuberosity subcutaneous. Table 1. OINA of the Gluteus Maximus muscle Ilium posterior to posterior gluteal line; dorsal surface Proximal Attachment of sacrum and coccyx; and sacrotuberous ligament Figure 4. Muscles around the Piriformis [Netter] Most fibers end in iliotibial Important Landmarks of the gluteal region: Distal Attachment tract, which inserts into ANATOMY Lower Limbs: Muscle and Fascia Page 3 of 35  → 📣 Blood vessels and nerves are named in relation to (L5, S1) →📣 this muscle. Action Lateral rotation of the thigh The superior and inferior arteries, veins and nerves are found superior to and inferior to the piriformis TRENDELENBURG TEST 📋 📋 respectively. Located below the gluteus medius and gluteus minimus Pear-shaped muscle found partly on the posterior wall of the lesser pelvis and partly posterior to the hip joint Table 4. OINA of the Piriformis Anterior Surface of the 2nd to 4th sacral segments; Proximal Attachment superior margin of greater sciatic notch and sacrotuberous ligament Superior border of the Distal Attachment greater trochanter of femur Branches of the anterior Nerve rami of S1 and S2 Abduction and lateral Action rotation of the thigh TRICEPS COXAE 📣 Figure 5. Trendelenburg Test[Moore] 📣📣 Occupies the gap between the piriformis and the Positive Trendelenburg Test 📣 All gluteal muscles are lateral rotators of the thigh quadratus femoris muscles. → Also called as unilateral leg test → Is a clinical test used to assess hip dysfunction. except for the Gluteus medius, Gluteus minimus and → When a person is asked to stand on one leg, the pelvis Tensor fasciae lata on the unsupported side descends, indicating that the Components: gluteus medius and minimus on the supported side are → Obturator internus weak, non-functional or paralyzed. This is appreciated → Gemelli superior/ inferior in patients with a lesion involving the superior gluteal ▪ “Gemelli = “Gemini” = “Twins” nerve, fracture of the greater trochanter and dislocation 📣 Table 5. OINA of the Superior/Inferior Gemellus of the hip joint. Superior: Ischial spine → Examiner examines if there is dropping, hitting or Proximal Attachment Inferior: Ischial tuberosity → 📣 sagging of the pelvis on the unsupported side. The test is considered negative when the patient is able to keep the pelvis is level or parallel to the Medial surface of the Distal Attachment greater trochanter (trochanteric fossa) of the → 📣 floor while the patient is standing on one foot. It is considered positive when there is a contralateral pelvic drop during the single leg femur Superior: Nerve obturator internus to → 📣 stance. In cases of a fracture of the greater trochanter and dislocation of the hip joint Nerve Inferior: Nerve to quadratus → The limb on the unsupported side of the pelvis becomes femoris too long and does not clear the ground when the foot is Abduction and lateral brought forward during the swing phase of walking. As Action such, the patient compensates as follows: rotation of the thigh Table 6. OINA of the Obturator Internus ▪ Waddling or Gluteal gait: He leans away from the unsupported side and raises the pelvis to allow Pelvic surface of ilium and adequate room for the foot to clear the ground as it Proximal Attachment ischium; and obturator swings forward. membrane ▪ Steppage gait: He lifts the foot higher as it is brought Medial surface of the forward. greater trochanter ▪ Swing-out gait: He swings the foot outward or Distal Attachment (trochanteric fossa) of the laterally femur Nerve to obturator internus Nerve (L5-S2) Abduction and lateral Action rotation of the thigh Table 7. OINA of the Quadratus Femoris Lateral border of the ischial Proximal Attachment tuberosity Quadrate tubercle on Distal Attachment intertrochanteric crest of Figure 6. Injury to the Superior Gluteal nerve[Moore] femur and area inferior to it INTRAMUSCULAR INJECTIONS Nerve Nerve to quadratus femoris ANATOMY Lower Limbs: Muscle and Fascia Page 4 of 35  Figure 8. Bones and Joints of the Hip Joint [Netter] 📣 A ball and socket joint permitting 3 axes of movement (Circumduction): → Flexion & Extension → Abduction & Adduction → Medial & Lateral Rotation Articular surfaces: Head of the femur (Ball) and 📣 Acetabulum of the hip bone (Socket) The hip joint is a very stable joint because of the following reasons: → More than half of the femoral head fits within the 📣 Figure 7. Intragluteal injections[Moore] In the clinics, intramuscular injections can be given in the areas listed on the figure above. acetabulum which is further deepened by the fibrocartilaginous ring attached to its rim called the Intramuscular Injections can be given safely in the Acetabular labrum. buttock/thigh following these techniques: → The presence of strong extracapsular ligaments. ▪ 📣 → A. Superolateral quadrant of the buttock Do not inject in the gluteal prominence as you 📣 → A thickened joint capsule. In general, Joint capsules are made up of two layers: may injure the sciatic nerve which lies deep in the muscles as seen in the picture above. → B. Superior to the line extending from the PSIS and to → 📋 External Fibrous Layer & Internal Synovial Membrane. Internal synovial membrane surrounds the joint or synovial cavity except for the areas that are covered by ▪ 📋 the superior border of the greater trochanter. Corresponds to the upper limit of the piriformis muscle articular cartilages → Some parts of the External Fibrous Layer thicken to form the ligaments. → C. Anterolateral part of the thigh where the needle D. LIGAMENTS OF THE GLUTEAL REGION pierces the tensor of the fascia lata → D. At the triangular area between the index finger that is directed to the ASIS and middle finger spread 📣 posteriorly until the iliac tubercle. There are several techniques for identifying the safest area to administer intramuscular injections in the gluteal region. One method is to divide the gluteal region into four quadrants. The safe area for injection corresponds to the superior lateral portion of the gluteal region. You can also locate the safe area by identifying the skin dimple in the gluteal region, which typically overlies the posterior 📣 superior iliac spine. If you draw an imaginary line from this skin dimple to the superior border of the greater trochanter, the area Figure 9. Extracapsular Ligaments of the Hip Joint [Dr. Uy’s PPT] above this line is considered safe for injections. Extracapsular Ligaments: Alternatively, you can administer the injection in the anterolateral part of the thigh, where the needle will 📣 → Iliofemoral - Prevents Hyperextension 📣 ▪ Aka the Y ligament of Bigelow 📣 penetrate the tensor fascia latae. Another technique involves using your fingers to mark the injection site: place your index finger over the anterior 📣 ▪ ▪ The strongest ligament in the body Reinforces the hip joint anterosuperiorly superior iliac spine (ASIS) and your middle finger on the iliac tubercle. The triangular area formed between your 📣 → Pubofemoral - Prevents Over Abduction ▪ Reinforces the hip joint inferomedially index and middle fingers is a safe zone for administering 📣 → Ischiofemoral - Prevents hyperextension 📣 📣 ▪ Reinforces the hip joint posteriorly 📋 the intramuscular injection. Complications of improper technique include nerve injury, hematoma and abscess formation. ▪ Is the weakest among the 3 ligaments The only intracapsular ligament in the hip joint is the Head of the femur, which is very weak and of little clinical 📣 C. JOINTS OF THE GLUTEAL REGION importance to the integrity of the hip joint. HIP JOINT The hip joint is supplied by the Medial and Lateral femoral circumflex arteries, coming from the Deep femoral Artery and the Artery to the Head of the Femur, which is a 📣 branch of the Obturator Artery. But the main arterial supply comes from the Retinacular 📣 Arteries arising from the medial circumflex arteries. Damage to these arteries, like in the case of ephemeral neck fracture, can lead to avascular necrosis of the femoral head. III. FEMORAL REGION A. FASCIA OF FEMORAL REGION SAPHENOUS OPENING/HIATUS (FOSSA OVALIS) It is a gap/opening/hiatus or defect in the fascia lata. Located below the medial part of the inguinal ligament. Approximately 4 cm inferolaterally from the pubic tubercle. ANATOMY Lower Limbs: Muscle and Fascia Page 5 of 35  → Falciform Margin ▪ The inferolateral presenting margin. ▪ Enclosed by the cribriform fascia. → Cribriform Fascia ▪ Derivative of the membranous layer of the superficial fascia. Allows passage of the great saphenous vein and its tributaries as it drains into the femoral vein as well as the efferent lymphatic vessels coming from the superficial inguinal lymph nodes. Figure 12. Iliotibial Tract[2026 Trans] B. SUBFASCIAL SPACES OF THE FEMORAL REGION BOUNDARIES OF FEMORAL TRIANGLE A subfascial space located in the proximal third of the anterior aspect of the thigh. Table 8.Boundaries of the Femoral Triangle Superior Inguinal ligament Medial Adductor longus Figure 10. Saphenous Opening[Dr. Uy’s Lecture] Lateral Sartorius INTERMUSCULAR SEPTAE Medially: Pectineus Invaginations in the thigh sent by the deep fascia. They are as follows: → Medial intermuscular septum Floor 📣 Laterally: Iliopsoas Femoral nerve needs to be cut to able to see the ▪ Between the anterior and medial compartments. Iliopsoas → Posterior intermuscular septum Skin and the underlying ▪ Between the medial and posterior compartments Roof superficial and deep fascia → Lateral intermuscular septum The contents of the Femoral Triangle (lateral to medial): ▪ The strongest because it is reinforced laterally by the → Femoral nerve - is not enclosed in femoral sheath iliotibial tract. sheath The 3 septae attach to the linea aspera of the femur. → Femoral sheath and its contents: It divides the thigh into: ▪ Femoral artery in the lateral compartment → Anterior compartment ▪ Femoral vein in the middle or intermediate → Medial compartment compartment 📣 → Posterior compartment ▪ Deep inguinal lymph nodes − − (Node of Cloquet )📋 located medial to the femoral vein The structures above are enclosed by the femoral sheath except for the femoral nerve. Knowing the relationship of the structures within the femoral triangle is clinically important because the contents may be damaged during femoral hernia repair, nerve block, blood extraction, or other surgical procedures such 📣 as vascular axis for catheterization → Knowing the femoral triangle is also important when doing femoral tap in the clinical setting. For instance, you are tasked to get the arterial blood sample for arterial blood gas studies. You have to know the location of the femoral artery because it's the artery you have to hit in order to get an arterial blood sample. The area can be accessed for lymph node sampling so that the spread of carcinoma can be assessed clinically. Figure 11. Intermuscular Septum[Musculoskeletal Key] ILIOTIBIAL TRACT A lateral, longitudinal thickening of the fascia lata. It extends from the iliac tubercle to the lateral condyle of the tibia on the anterolateral tubercle also known as Gerdy’s Tubercle. It also receives the attachments of the tensor fascia latae and the gluteus maximus muscles. Figure 13. Contents of the Femoral Triangle[Cambridge University Press] ANATOMY Lower Limbs: Muscle and Fascia Page 6 of 35  FEMORAL SHEATH 📣 Continuation of the Transversalis fascia. Femoral sheath is around 3 to 4 cm and can be seen 📣 below the inguinal ligament. It is a continuation of the transversalis and iliopsoas 📣 fascia from the abdomen. It encloses only the femoral vessels and deep inguinal lymph nodes and not the femoral nerve. It is divided into the following compartments: → Lateral ▪ Occupied by the femoral artery → Middle/Intermediate ▪ Occupied by the femoral vein → Medial ▪ Corresponds to the femoral canal −📣 ▪ Contains the deep inguinal nodes Deep inguinal lymph nodes is also called the ❗ “Node of Cloquet” 💬 MNEMONICS NAVEL (from lateral to medial) → (Femoral) Nerve → (Femoral) Artery → (Femoral) Vein → Empty Space → Lymph Nodes ADDUCTOR CANAL Otherwise known as the Subsartorial (because it lies Figure 14. Outline of the Femoral Triangle[Moore & Dr. Uy’s Lecture] under the sartorius muscle) or Hunter canal 📣 Found in the middle third of the anterior thigh The femoral triangle is located in the upper third of the Allows passage of the femoral vessels (to reach the anterior aspect of the thigh. It is bounded superiorly by the popliteal fossa), saphenous nerve, and nerve to vastus inguinal ligament, laterally by the sartorius muscle, and medialis medially by the adductor longus muscle. The triangle’s Extends from the bisection of the adductor longus boundaries are formed by the skin and the superficial and muscles and sartorius to the entrance of the femoral deep fasciae of the thigh. The floor of the triangle is formed vessels into the adductor hiatus medially by the pectineus muscle and laterally by the Table 9. Boundaries of the Adductor Canal iliopsoas muscle. Note that the iliopsoas muscle might not Lateral Vastus Medialis muscle be visible in some photographs unless the femoral nerve is Anteromedially Sartorius reflected or removed, as it lies just underneath the Adductor magnus and Posteriorly 📣 distribution of the femoral nerve. The contents of the femoral triangle, from lateral to medial, are the femoral nerve, femoral artery, and femoral Adductor longus vein. Medial to the femoral vein is the deep inguinal lymph node, which is not shown here. The femoral vessels and deep inguinal lymph nodes are enclosed by the femoral sheath. This sheath, approximately 3-4 cm below the inguinal ligament, is a continuation of the transversalis and iliopsoas fascia from the abdomen and encloses only the femoral vessels and deep inguinal lymph nodes, not the 📣 femoral nerve. The femoral sheath is divided into three compartments: the lateral compartment contains the femoral artery, the middle compartment encloses the femoral vein, and the medial compartment, known as the femoral canal, contains the deep inguinal lymph nodes, also referred to as the Figure 15.Adductor Canal[Gray’s Atlas of Anatomy] 📣 nodes of Cloquet. Understanding this arrangement is important in clinical practice. For instance, when performing a femoral puncture to obtain an arterial blood sample for gas studies, it is crucial to know the location of the femoral artery. Similarly, for procedures such as carotid angiography or cardiac catheterization, accessing the femoral artery is essential. Additionally, lymph node sampling in the inguinal region can help assess the spread of cancer from other areas, such as the pelvis or abdomen, or from soft tissues of the thigh. ANATOMY Lower Limbs: Muscle and Fascia Page 7 of 35  Table 10.OINA of the Pectineus muscle Proximal Attachment Superior pubic ramus Distal Attachment Pectineal line of the femur Femoral nerve (L2, L3) and Nerve Accessory Obturator Nerves Flexes, adducts, and Action medially rotates (internal rotation) the thigh Figure 16. Contents of the Adductor CanalGray’s Atlas of Anatomy] ADDUCTOR HIATUS Opening in the aponeurotic distal attachment of the adductor magnus The femoral vessels change their name to popliteal vessels once they pass through the Adductor hiatus C. MUSCLES OF THE FEMORAL REGION ❗MNEMONICS Figure 18. Pectineus muscle[Gray’s Atlas of Anatomy] ANTERIOR THIGH MUSCLES Flexors of the thigh and extensors of the knee Innervated by the Femoral Nerve (with some FADIR exceptions) → Flexion This includes the following: Pectineus muscle, Iliopsoas → Adduction muscle, Sartorius muscle, and the Quadriceps Femoris. → Internal Rotation ILIOPSOAS → 📋 Chief flexor of the thigh at the hip joint Arises from the posterior abdominal wall, it attaches → 📋 to the lesser trochanter of the femur The only muscle that has attachments to the vertebral column, pelvic bone, and the femur. 📣📣 Combination of iliacus and psoas major. Originated from the vertebral column The abdominal cavity needs to be opened up in order 📣📖 to see the origin of the iliopsoas muscle It inserts into the lesser trochanter Psoas minor is a small, inconsistent muscle present in approx. 60% of the population and may only be present → 📋 unilaterally Of little importance in iliopsoas action. Some → 📋 references do not consider it part of the iliopsoas If present, found on anterior surface of psoas major Table 11.OINA of the Iliopsoas muscle Muscle: Iliopsoas Psoas Psoas Iliacus Figure 17. Anterior Thigh Muscles[Netter] Major Minor Posterior abdominal walls Proximal Sides of Sides of Iliac crest, ❗️ PECTINEUS attachment T12-L5 T12-L1 Iliac fossa, accessory obturator nerve (posterior part)📋 Innervated by the femoral nerve (anterior part) and vertebrae vertebrae ala of The transitional muscle because of its position between and discs and sacrum, the anterior compartment and middle compartment of the between intervertebr anterior 📣📣 thigh. them; al discs sacro-iliac Most medial of the anterior thigh compartment transverse ligaments It crosses the hip joint so it is expected to flex the thigh processes of all lumbar 📋 at the hip joint, adduct and medially rotate the thigh. When it contracts, it adducts, flexes, and medially/internally rotates the thigh (FADIR) vertebrae ANATOMY Lower Limbs: Muscle and Fascia Page 8 of 35  Distal Lesser Pectineal Tendon of attachment trochanter line and psoas of the to iliopubic major, femur eminence lesser via trochanter iliopectineal and femur arch next to it Nerve Anterior Anterior Femoral rami of rami of Nerve (L2, lumbar lumbar L3) nerves (L1, nerves (L1, L2, L3) L2) Action: Act conjointly in flexing the thigh at hip joint and in stabilizing this joint Figure 20. Sartorius muscle[Netter] QUADRICEPS FEMORIS 📣 It is the chief extensor of the leg. Major action: Extends the leg at the knee joint 📣 It forms the main bulk of the anterior thigh compartment. Quadriceps → since it has 4 heads Consists of: → Rectus Femoris − Called the kicking muscle because it is the muscle used when the thigh is hyper extended and the knee is flexed in initiation of kicking − Crosses both the hip and the knee joints as it runs o 📣 down straight the thigh Only muscle of the quadriceps femoris that crosses the hip joint since it arises from the anterior inferior iliac spine Figure 19.Iliopsoas muscle[Netter] → 3 Vasti: ▪ Vastus lateralis 📋 SARTORIUS ▪ Vastus medialis The longest muscle runs obliquely from the anterior ▪ Vastus intermedius superior iliac spine to the upper section of the medial 📣 − Lies just beneath the rectus femoris 📣 Diagonally placed surface of the tibia, crossing both the hip and knee joints. These 4 parts of the quadriceps femoris will converge distally to form the quadriceps tendon which will enclose It crosses both the hip and knee joint. the patella. When both the left and the right sartorius are contracting, it It continues to become the patellar ligament that attaches brings the lower extremities into a cross-legged sitting position similar to that adopted by the tailors when sewing ❗️ to the tibial tuberosity → The patella is the largest sesamoid bone in the body into which the vastus lateralis and the vastus seams by hand. 📣 Sometimes called the Tailor muscle. medialis attach independently forming the lateral and 📣 Flexes the hip joint and the knee joint and abducts and medial patellar retinaculum laterally rotates the thigh ▪ The patellar ligament and the lateral and medial Table 12.OINA of the Sartorius muscle patellar retinaculum will strengthen the knee joint Anterior superior iliac spine anteriorly. Proximal Attachment and superior part of notch → The patellar retinaculum reinforces the joint capsule of inferior to it the knee joint Superior part of the medial Table 13.OINA of the Quadriceps Femoris muscle Distal Attachment Rectus Femoris: Anterior surface of the tibia Nerve Femoral nerve (L2, L3) inferior iliac spine and ilium Flexion, Abduction, and superior to acetabulum Lateral/External rotation of Vastus Lateralis: Greater the thigh at the hip joint; trochanter and lateral lip of Action linea aspera of femur Flexes leg at knee joint (Medial rotating leg when Proximal Attachment Vastus Medialis: knee is flexed) Intertrochanteric line and ❗ medial lip of linea aspera of 💬 MNEMONICS femur FAbER Vastus Intermedius: → Flexion Anterior and lateral → Abduction surfaces of shaft of femur 💬 → External Rotation When the knee is flexed, it will medially rotate the leg. Distal Attachment Quadriceps tendon (where the patella is embedded) ANATOMY Lower Limbs: Muscle and Fascia Page 9 of 35  Tibial tuberosity via patellar ligament Medial and lateral vasti also attach to tibia and patella via aponeurosis Nerve Femoral nerve (L2, L3, L4) Extend leg at knee joint Rectus femoris steadies hip Action joint and helps Iliopsoas flex the thigh Figure 22. Adductor muscles and Gracilis[Dr. Elevazo’s ppt]] MEDIAL THIGH MUSCLES Made up of the three adductor muscles: → Adductor longus → Adductor brevis → Adductor minimus ▪ Lies beneath the adductor brevis Also include: → Gracilis → Obturator externus Nerve Supply: Obturator Nerve Function: adduction and medial/internal rotation of the Figure 21. Quadriceps Femoris muscle[Netter] → 📋 thigh Except for the obturator externus (laterally rotate 📋 PATELLA The four quadriceps muscles all converge onto 📣 the thigh) If you cut through the adductor longus muscle, you 📋the patella through the quadriceps femoris tendon Extends downward to create the patellar ligament, which connects to the tibial tuberosity. 📣will find the adductor brevis muscle If you cut through the adductor brevis muscle, you will find the adductor minimus muscle. 📋 It is the largest sesamoid bone. The three adductors rise from the pubis and attach ❗️ The vastus lateralis and vastus medialis attach distally to the linea aspera of femur (common distal separately to the patella, forming the lateral and attachment). medial patellar retinacula, which reinforce the knee Also made up by the gracilis and the obturator externus. joint capsule. These muscles adduct and medially rotate the thigh except PES ANSERINUS for the obturator externus which laterally rotates the thigh. Literally means “goosefoot” 📋 Refers to the goosefoot-like arrangement of the distal ADDUCTOR LONGUS attachment of the following muscles on the superior part of Can’t be seen if you don’t remove the pectineus 📖 the medial surface of the tibia Common tendinous insertion made up of muscles representing each compartment of the thigh The horseback-riding muscle as both muscles are actively contracting when riding on horseback → Sartorius - anterior compartment Table 14.OINA of the Adductor Longus muscle → Gracilis - medial compartment Body of the pubis inferior to → SemiTendinosus - posterior compartment Proximal Attachment pubic crest MNEMONIC: “SGT”/Sergeant Middle third of linea aspera Made up of muscles representing each compartment of the Distal Attachment of femur thigh. Obturator nerve and branch Nerve of anterior division (L2, L3, L4) Action Adducts thigh 📋 ADDUCTOR BREVIS Seen once the adductor longus is removed Demarcation between the anterior and posterior divisions 📣 of the Obturator nerve due to its position between them. → ❗️ Muscle of the medial thigh compartment is supplied by the obturator nerve. Upper anterior part of the adductor magnus. Table 12.OINA of the Adductor Brevis muscle ANATOMY Lower Limbs: Muscle and Fascia Page 10 of 35  Body and inferior ramus of OBTURATOR EXTERNUS Proximal Attachment 📣 pubis Laterally rotates the thigh Pectineal line and proximal → The odd man out among the other medial thigh Distal Attachment part of linea aspera of the muscles because this muscle is coming from the femur margins of obturator foramen and obturator membrane 📣 Obturator nerve and branch that covers the obturator foramina. Nerve of anterior division (L2, L3, → Medial thigh muscles - flex the thigh at the hip joint L4) and medially rotate the thigh Adducts thigh Table 17. OINA of the Obturator Externus muscle Action Flexes thigh to some extent Margins of obturator Proximal Attachment foramen and obturator 📋 ADDUCTOR MAGNUS membrane Upper and anterior part of the adductor magnus Trochanteric fossa of the Distal Attachment Largest, most powerful, and most posterior muscle in the femur ❗️ medial group Nerve Obturator nerve (L3, L4) It has two parts: Laterally rotates the thigh; → Upper Anterior part: Adductor minimus Action steadies head of femur in − Innervation: Obturator Nerve acetabulum → Ischiocondylar portion: Hamstring part 📋 − Innervation: Tibial Nerve Lies beneath the adductor brevis and gracilis POSTERIOR THIGH MUSCLES Table 15.OINA of the Adductor Magnus muscle Adductor part: inferior Proximal Attachment ramus of pubis Adductor part: gluteal Distal Attachment tuberosity, linea aspera, medial supracondylar line Adductor part: Obturator Nerve nerve (L2, L3, L4) and Adducts thigh Action Adductor part: Flexes thigh Figure 24. Posterior Thigh Muscles [Netter] Figure 23. Adductor muscles and Gracilis[Moore] Figure 25. Attachments of the posterior thigh muscles [Moore] GRACILIS 📣 All arise from the ischial tuberosity except for the short head of the biceps femoris, which arises from the linea Weakest among the adductors and most superficial aspera of the femur. Commonly sacrificed to replace a damage hand muscle or → 📣 non-functional external anal sphincter Gracilis can be harvested for grafting during reconstructive hand surgery. SEMITENDINOSUS Beside the semimembranosus Inserts on the superior part of the medial portion of tibia Table 16. OINA of the Gracilis Minimus muscle → Rotates the Leg Medially Body and inferior ramus of Joins sartorius and gracilis in the formation of pes Proximal Attachment pubis anserinus Superior part of medial Table 18. OINA of the Semitendinosus Distal Attachment surface of tibia Proximal Attachment Ischial tuberosity Nerve Obturator nerve (L2, L3) Medial surface of superior Distal Attachment Adducts thigh; flexes leg part of tibia Action and helps rotate leg Tibial division of sciatic medially Nerve nerve part of tibia (L5, S1, S2) Action Extends thigh; ANATOMY Lower Limbs: Muscle and Fascia Page 11 of 35  Flexes leg and rotates it Common Origin - ischial tuberosity (except the short head medially when knee is of biceps femoris) flexed. Nerve Supply: TIBIAL NERVE except the short head of the When thighs and legs are biceps femoris (common peroneal nerve) flexed, these muscles can extend the trunk. Table 21. OINA of the Adductor Magnus (Hamstring Part) Proximal Attachment Ischial tuberosity Adductor tubercle of the Distal Attachment SEMIMEMBRANOSUS femur Rotates leg medially when the knee is flexed Tibial part of the sciatic Nerve nerve (L4) → 📣 Encloses the tendon of semitendinosus Inserts on the superior part of the medial portion of Action Adducts and extends thigh → 📣 the tibia. Pes anserinus is made up of sartorius, gracilis, and IV. KNEE REGION → 📣 semitendinosus. Together with the semitendinosus, rotates the leg A. KNEE JOINT 📣📣 medially when the knee is flexed. ANTERIOR KNEE Table 19. OINA of the Semimembranosus The Largest and most stressed joint in the body. Proximal Attachment Distal Attachment Ischial tuberosity Posterior part of medial 📣 Classified as a synovial modified hinge joint. Primarily allowing Flexing and Extension, and some condyle of the tibia Tibial division of sciatic 📋 Medial and Lateral rotation when the knee is flexed. Hinge movements are combined with rolling and gliding Nerve nerve part of tibia (L5, S1, S2) and with vertical axis rotation Table 22. Boundaries of the knee Joint 📋 Extends thigh; Lateral Iliotibial tract Flexes leg and rotates it Anterior Patellar ligament Action medially when knee is Anterolateral Lateral and medial patellar retinaculum flexed. 📋 Articular surfaces: → 2 femorotibial articulations: Lateral and Medial BICEPS FEMORIS Found on the lateral aspect 📋 articulation between the femoral and tibial condyles → 1 Intermediate femoropatellar articulation between the patella and femur → Workhorse of Hip extension → Has longhead (tibial nerve) and short head (common peroneal nerve) → 📣 → Rotates the leg laterally when the knee is flexed Arises from the linea aspera of the femur Table 20. OINA of the Biceps Femoris Long head: Ischial tuberosity Proximal Attachment Short head: linea aspera and lateral supracondylar line of femur Lateral side of head of fibula Figure 26. Meniscus of the Knee [Netter] Distal Attachment Tendon is split at this site by fibular collateral ligament of the knee Long head: tibial division of sciatic nerve (L5, S1, S2) Nerve Short head: Common fibular (peroneal) division of sciatic nerve (L5, S1, S2) Flexes leg and rotates it laterally when knee is Action flexed. Extends thigh ADDUCTOR MAGNUS (ISCHIOCONDYLAR PART) Figure 27. Ligaments of the Knee Joint, right knee in Extension [Netter] 📣 Posterior part of the Adductor magnus All hamstrings are innervated by the tibial nerve 📣 The Knee joint is mechanically weak because of the relative incongruence between the articulating surfaces, except for the short head of the biceps femoris, which is more compared with the two balls sitting on a wide innervated by the common peroneal nerve 📣 tabletop. The knee joint is most stable in direct extended position ANATOMY Lower Limbs: Muscle and Fascia Page 12 of 35  📣 Joint stability is dependent more on the surrounding muscles and tendons, as well as the ligaments connecting 📋The most important muscle that stabilizes the knee joint the femur and the tibia is the Quadriceps femoris, specifically the inferior fibers of both Vastus medialis and lateralis Figure 29. Knee Posterior View [Netter] → 📣 Intracapsular Ligaments Cruciate ligaments are criss-crossing structures → 📣 within the joint capsule but outside the synovial cavity. Maintains contact between the femoral and tibial condyles during motion of the knee. → Anterior Cruciate (ACL) ▪ Prevents posterior displacement/rolling of the femur on the tibia during flexion and hyperextension of the ▪ 📣 knee joint. Weaker of the two cruciate ligaments. → Posterior Cruciate (PCL) ▪ Prevents anterior displacement/rolling of the femur on the tibia during extension and hyperflexion of the 📋 Figure 28. Ligaments of the Knee Joint, Right Knee in Flexion[Netter] The joint capsule contains an external fibrous layer of the capsule (fibrous capsule) and an internal synovial knee joint. membrane lining the articular cavity’s internal surfaces that 📣 isn’t covered with articular cartilage The Joint capsule of the knee joint is reinforced by the intracapsular and the extracapsular ligaments. Extracapsular or the Capsular or the Intrinsic ligaments include: ▪ 📣 → Patellar Ligament Extension of the quadriceps tendon and it extends ▪ 📋 to the tibial tuberosity 📣 Anterior ligament of the knee joint Figure 30. Anterior Aspect of the Menisci[Netter] ▪ ▪ 📋 Reinforcing the joint capsule anteriorly Attachment: Lower border of the patella and extend to the tibial tuberosity → 📣 Menisci (Semilunar cartilages) Are crescentic plates of fibrocartilage attached firmly → Fibular or Lateral Collateral & Tibial or Medial 📣 on the peripheral surface of the tibia. 📣 Collateral → Functions to deepen the articulating surfaces of the ▪ Run along the sides of the knee and limits side-to-side movement → 📣 tibia to receive the femoral condyles Act as shock absorbers or knee stabilizers → Medial = Larger, C-shaped, broader and attached to → Oblique popliteal - expansion of semimembranosus ▪ 📣 tendon & Arcuate popliteal - arises from the fibular head Reinforce the joint capsule posteriorly tibial collateral ligament. Lateral = Smaller, circular and more freely movable ANTERIOR & POSTERIOR DRAWER TEST ANATOMY Lower Limbs: Muscle and Fascia Page 13 of 35  Figure 33. McMurray’s Test [Wikism.org] [Moore] Figure 31. Drawer test Purpose: McMurray's test is a clinical examination TEST FOR MENISCAL TEAR maneuver used to assess the integrity of the menisci in the knee joint, particularly for identifying tears in the Tests to assess the integrity of the cruciate ligaments and medial and lateral menisci. → 📣 the menisci in cases of knee injury: The Anterior and Posterior drawer tests are done with the patient lying on his back, Hip flexed to 45°, and → Anatomical Context: ▪ Menisci: The knee joint contains two crescent-shaped cartilaginous structures called the the knee is flexed at 90°, with the foot flat on the medial meniscus and lateral meniscus. These → 📣 examining table. The examiner then grasps the proximal portion of the leg and applies a sudden firm pull anteriorly (in the structures function to absorb shock, distribute load, and enhance joint stability. − Medial Meniscus: C-shaped and larger, it is firmly case of the Anterior Drawer test) or a sudden firm push attached to the medial collateral ligament (MCL). → 📣 posteriorly (in the case of the Posterior Drawer test) The tests are positive for a tear in the ligaments when there is laxity elicited during the anterior − Lateral Meniscus: Circular and smaller, it is more mobile and not directly attached to the lateral collateral l