Ana 1.06 Gluteal Region and Thigh PDF

ANATOMY Gluteal Region and Thigh Block 1 Arturo M. Decano, MD, FPCS, FACS, FPSGS, FPSAi | August 10, 2023...

ANATOMY Gluteal Region and Thigh Block 1 Arturo M. Decano, MD, FPCS, FACS, FPSGS, FPSAi | August 10, 2023 Trans 1.06 OVERVIEW ○ Anterior: Knee I. Lower Limb B. Muscles of Pelvic Cavity ○ Posterior: Popliteal fossa A. Surface Anatomy of the Participating as Muscle of Lower Limb Lower Extremity B. Bones of the Lower VI. Lumbosacral Plexus Extremity A. Muscles and Nerves of II. Pelvic Girdle Pelvic Cavity in Relation A. Lateral Surface of the Hip to Lower Extremities Bone B. Ligaments of Hip Joint Bony Markings VII. Gluteal Region B. Medial Surface of the Hip A. Surface Anatomy Bone B. Gluteal Muscles III. Femur VIII. Gluteal Region IV. Joints and Ligaments of the A. Surface Anatomy Pelvis B. Gluteal Muscles A. Hip Joint Superficial B. Ligaments of Hip Joint Deep C. Knee Joint Gluteal vessels Articulating Surface IX. Thigh of the Knee Joint A. Compartment of the Figure 1. Surface Anatomy of the Lower Limb Superior View of the thighs Tibial Plateau Anterior Cruciating Ligaments Compartment A. Bones of the Lower Extremity V. Lumbar Plexus Medial Compartment A. Relationship of the Posterior Lumbar Plexus to the Compartment Posterior Abdominal B. Blood Supply Wall C. Popliteal fossa ABBREVIATIONS ACL Anterior Cruciate Ligament ASIS Anterior Superior Iliac Spine AIIS Anterior Inferior Iliac Spine PCL Anterior Cruciate Ligament PSIS Posterior Superior Iliac Spine PIIS Posterior Inferior Iliac Spine LEARNING OBJECTIVES Describe the body and ligamentous components of the Figure 2. Bones of the Lower Extremity pelvic girdle Discuss the components of the hip joint and correlate Same architecture with upper extremities movements with the muscles producing actions in this joint Hip bone Describe the anatomy of the gluteal muscles, including their ○ Equivalent to the pectoral girdle nerve supply, and their actions in locomotion ○ Joins together with other structures to enclose the pelvic Discuss the general plan and major branches of the lumbar cavity plexus Femur Discuss the compartments of the thigh, its muscles, their ○ Equivalent to Humerus nerve supply, and their actions in locomotion ○ It transmits body weight from the hip bone to the tibia Define the regional deep fascia of the lower limb and their when a person is standing. (Moore’s. 2018) regional specialization such as iliotibial tract Hip joint Describe the femoral triangle and adductor canal, their ○ Equivalent to shoulder joint contents and the spatial relationships of the structures Knee joint passing through them ○ Equivalent to elbow joint Tibia and Fibula I. LOWER LIMB ○ Equivalent to Radius and Ulna A. Surface Anatomy of the Lower Limb ○ Tibia: Arrangement of lower extremities is almost the same as Located on the anteromedial side of the leg, nearly upper extremities parallel to the fibula. Borders between torso and lower extremities: ○ Fibula: ○ Anterior - Inguinal ligament The fibula has no function in weight bearing. It Groin in layman's term serves mainly for muscle attachment ○ Posterior - Gluteal region Tarsals and Metatarsals Buttocks in layman’s term ○ Equivalent to Carpals and Metacarpals Difference of anterior and posterior view Phalanges (Toes) Page 1 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh II. PELVIC GIRDLE Pelvis - means basin Ring-like bony structure that connects the lower limb to the trunk Composed of the right and left hip bones ○ Connected anteriorly by a very large cartilaginous structure called symphysis pubis ○ Articulates posteriorly with the sacrum (fusion of five originally separate sacral vertebrae) and coccyx (fusion of 4 coccygeal vertebrae) Bears the weight of the upper body when sitting and transfers the weight to the lower pelvicular skeleton when standing Pelvis provides attachment for muscles and ligaments of the abdomen superiorly and the muscles and ligaments of the lower extremity inferiorly Figure 4. Lateral Surface of the Right Hip Bone Also contains and protects the organs located in the abdomino-pelvic cavity Bony Markings ○ Cavity in the lower portion of the abdomen All elevations and depressions will be named according to The pelvic bone is not positioned like a basin, even though it the original name of the bone is called that way. ○ ⭐ The ASIS and the pubic tubercle are lying on the 4 Iliac spines: ○ Anterior Superior Iliac Spine (ASIS) same plane → Coronal Plane ASIS: Anterior-Superior Iliac Spine Most popular and easily palpable (At the end of the ○ You can see the entire sacrum inguinal ligament) Used as a landmark in surgery ○ Anterior Inferior Iliac Spine (AIIS) ○ Posterior Superior Iliac Spine (PSIS) ○ Posterior Inferior Iliac Spine (PIIS) Iliac crest: Most superior part of the hip bone and is in between the ASIS and the PSIS Ischial spine: Located in the ischium Ischial tuberosity: Where we sit and bears body weight while sitting Pubic tubercle: Can also be palpated Figure 3. The Pelvic Girdle A. Lateral Surface of the Hip Bone Acetabulum ○ Cup-shaped socket which articulates with the head of the femur to form the hip joint (ball and socket joint) The hip bone is a solid flat bone formed by three primary bones: Figure 5. Bony Markings of the Right Lateral Hip ○ Ilium - located superiorly; fan shaped part of the bone ○ Ischium - forms the posterior-inferior part B. Medial Surface of the Hip Bone ○ Pubis - forms the anteromedial part [Moore, 2018] Despite being similar to a basin, it is positioned in such a From birth to puberty, the primary bones are separated by a way that the ASIS and the pubic tubercle lie on the same Y-shaped triradiate cartilage centered on the acetabulum coronal plane ○ All primary bones contribute to the formation of the acetabulum Sacrum Primary bones begin to fuse between the ages of Articulates with the ilium bilaterally via the sacroiliac joint 15 and 17 Position of the ASIS allows this to be almost entirely seen Fusion completes between 20-25 years of age ○ In older adults, little or no trace of lines of the primary Obturator foramen bones is visible Muscles, nerves, and blood vessels passes through this foramen on their way to the lower extremities Opening is not completely free ○ Obturator membrane Covers the foramen almost entirely ○ Obturator canal Gap that is not covered by the obturator membrane Page 2 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh Passageway for the obturator neurovascular a person is standing(Moore, 2018) structures The proximal femur is “bent” (L-shaped) so that the long axis of the head and neck projects superomedially at an Sciatic notch angle to that of the obliquely oriented shaft(Moore, 2018) Inverted U-shaped space between the hip bone and sacrum ○ Angle of inclination: acute angle averaging 126° Becomes a foramen with a ligament attached to the sacrum and ischial tuberosity called the sacrotuberous ligament Sacrospinous ligament Divides the sciatic foramen into two ○ Greater Sciatic Foramen (bigger and superior) ○ Lesser Sciatic Foramen (smaller and inferior) Pelvic structures exit through the two foramina on their way to the gluteal region Figure 8. Parts of the Femur Table 1. Parts of the Femur PARTS DESCRIPTION Greater Trochanter Superiorly and Laterally Providing attachment and leverage for abductors and rotators of the thigh Neck Lesser Trochanter Inferiorly and Medially Give tendinous attachment to the primary flexor of the thigh (iliopsoas) Covered with articular cartilage, except for a medially placed depression or pit Slanted Head Articulates with the acetabulum of the hip. ○ Position is perpendicular to the acetabulum Slanted downwards and medially so that the knee is almost occupying the Shaft center of the gravity. It is to easily Figure 6. Medial surface of the Hip bone. A) Emphasis on the sciatic notch and Obturator foramen. B) Medial surface with sacrum and sciatic foramen support the weight of the human body An elevation along the shaft responsible Iliacus Linea aspera for aponeurotic attachment for thigh Pelvic muscle that occupies the Iliac fossa adductors A powerful flexor of the thigh Condyles (lateral and Articular surfaces of the femur; medial) articulates with the knee joint Epicondyles (lateral Function as muscle attachments and medial) IV. JOINTS AND LIGAMENTS A. Hip Joint The connection between the lower limb and the pelvic girdle It is a strong and stable multiaxial ball-and-socket type of synovial joint. During standing, the entire weight of the upper body is transmitted through the hip bones to the heads and necks of the femora. Figure 7. Iliacus muscle attachment to the hip bone Source: Somatic movement center III. FEMUR Equivalent to humerus. The femur is the longest and heaviest bone in the body. (Moore, 2018) It transmits body weight from the hip bone to the tibia when Figure 9. Parts of the Hip Joint Page 3 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh MOVEMENTS OF THE HIP JOINT Table 2. Parts of the Hip Joint Flexion (anteriorly) PARTS DESCRIPTION Extension (posteriorly) Forms a synovial, ball and socket joint Lateral rotation with the acetabulum of the coxal bone Medial rotation Almost entirely covered by the Abduction Head of the femur acetabulum (socket) Adduction More stable than the shoulder joint but less mobile B. Knee Joint Ligament of the head Transmits an artery coming from the The largest and most superficial joint(Moore, 2018) of the femur obturator artery to the head of the femur Primarily a hinge type of synovial joint, allowing flexion and Covered by cartilage almost completely extension; however, the hinge movements are combined Cartilage is horseshoe shaped with gliding and rolling and with rotation about a vertical Acetabulum Has a deficient inferior aspect known as axis. (Moore, 2018) the acetabular notch Composed of three bones: femur, patella, tibia Non-articular floor of the acetabulum ○ Femur - articulates with the tibia not covered by cartilage ○ Patella - a sesamoid bone (form from fibrous tissue) ○ Tibia - bears the weight of the body Acetabular fossa Covered by loose connective tissue covered by synovial membrane ⭐ Fibula - a leg bone but NOT a part of the knee joint; NOT Continuous with the acetabular notch a weight bearing bone Similar to glenoid labrum, an extension Condylar type synovial joint between two condyles of the Acetabular labrum of cartilage to better accommodate the femur and tibia (Halliday & Chung, 2020) head of the femur ○ also includes a saddle joint between the femur and the Contains the transverse acetabular patella(Halliday & Chung, 2020) Acetabular notch The knee joint is relatively weak mechanically because of ligament which joins with the cartilage the incongruence of its articular surfaces (Moore, 2018) Ligaments of the Hip Joint ○ Most important muscle in stabilizing the knee joint is the Ligaments maintain the stability of the hip joint large quadriceps femoris ○ Stability of the knee joints depends on: Iliofemoral(Moore, 2018) 1. The strength and actions of the surrounding Body’s strongest ligament. muscles and their tendons Prevents hyperextension of the hip joint during standing by 2. The ligaments that connect the femur and tibia. screwing the femoral head into the acetabulum Pubofemoral(Moore, 2018) Blends with the medial part of the iliofemoral ligament Tightens during both extension and abduction of the hip joint. Ischiofemoral(Moore, 2018) Weakest of the three ligaments Spirals superolaterally to the femoral neck, medial to the base of the greater trochanter. Figure 11. The knee joint Posteriorly located Articulating Surfaces of the Knee Joint Table 3. Ligaments of the Hip Joint Meniscus ○ C-shaped cartilages LIGAMENTS ○ For greater stability of the joint and shock absorber Iliofemoral Ligament that attaches the ilium to the femur ○ Separate from the cartilage of the tibial plateau Pubofemoral Ligament that attaches the pubis to the femur Lateral meniscus: more free Ischiofemoral Ligament that attaches the ischium to the femur Medial meniscus: attached to another ligament, tibial collateral ligament Figure 10. Ligaments of the Hip Joint Figure 12. Articulating surfaces of the knee joint (Sagittal Section) Page 4 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh Superior View of the Tibial Plateau of the thigh ○ Will exit the behind or below the inguinal ligament Obturator Nerve ○ Pass through the obturator foramen and obturator membrane ○ Innervates all the muscles located in the medial compartment of the thigh ○ Will exit the obturator foramen to the canal Lumbosacral trunk is where the L4 and L5 will join together Figure 13. Superior view of tibial plateau → join the sacral trunk Genitofemoral nerve(Batch 2027) Table 4. Structures of the Tibial Plateau ○ Genitalbranch:[motor] cremaster muscle of males Structures Description ○ Femoral branch:[sensory] for medial aspect of thigh Medial Meniscus Attached to tibial collateral ligament ○ Pierces Psoas Major Free from ligaments of knee; uninjured Lateral Cutaneous Nerve of the Thigh(Batch 2027) Lateral Meniscus during knee injuries ○ Innervates lateral aspect of thigh Tibial Collateral Injury to this ligament will injure medial Ligament meniscus Cruciate Ligaments Cruciate means cross ○ The ligaments cross each other forming a cross. It provides stability of the joint Anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) ○ Named according to attachment to the tibia ACL is a weaker ligament than the posterior ligament Table 5. Cruciate Ligaments Structure Description Function Prevents anterior posterior Attached to anterior Anterior dislocation of the tibia and Figure 14. Lumbar Plexus aspect of the tibia and cruciate posterior dislocation of the posterior aspect of ligament femur, and hyperextension femur of the knee ⭐ A. Relation of Lumbar Plexus with the Posterior Abdominal Wall Prevents posterior anterior Psoas major and minor Attached to posterior Posterior dislocation of the tibia and ○ Begins from the vertebrae → Medial side of iliac fossa → aspect of the tibia and cruciate anterior dislocation of the Femur anterior aspect of ligament femur, and hyperflexion of femur the knee ⭐ ○ Where all nerves of the lumbar plexus exit Iliopsoas muscle ○ Iliacus and psoas muscles V. LUMBAR PLEXUS They have a single tendon and they are collectively Table 6. Nerves of the Lumbar Plexus called iliopsoas muscle. Nerve Innervation Obturator foramen is directed downwards and medially. T12 Subcostal nerve Muscles below the ribs ○ Covered by obturator muscle. L1 Iliohypogastric nerve Obturator internus - covering the insides of the Lower abdominal wall L1 Ilioinguinal nerve obturator foramen Genital branch (motor) Obturator externus - covering the obturator foramen Ex: Cremaster reflex externally L1-2 Genitofemoral nerve Femoral branch (sensory) Their tendons will exit the lesser sciatic foramen Ex: Medial thigh Lateral cutaneous L2-3 Sensory of anterolateral thigh nerve of the thigh L2-4 Femoral Nerve ⭐ Iliacus, flexors of the hip, extensors of the knee L2-4 Obturator nerve ⭐ Adductor muscles of the thigh L4-5 Lumbosacral trunk Posterior and lower thigh Mnemonic: Sweet, I Twice Get Laid on Friday Openings Lumbar plexus: T12 to L5 ⭐ Femoral nerve and Obturator nerve have L2, L3, and L4 as roots Femoral Nerve ○ Located on the anterior thigh and Figure 15. Lumbar Plexus in relation to the Posterior Abdominal Wall ○ Innervates all the muscles in the anterior compartment Page 5 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh Table 7. Direction of Exit of Lumbar Plexus in Relation to Psoas Major(Batch 2027) Partially covers Converges posteriorly Obturator Direction of Exit Nerve obturator foramen and exits at the lesser Internus Subcostal nerve (gap: obturator canal) sciatic foramen Iliohypogastric nerve Exits through the Obturator From the lumbosacral Lateral Ilioinguinal nerve obturator canal with nerve plexus Lateral cutaneous nerve of the thigh obturator vein and artery Femoral nerve Landmark for dividing Pierces through Genitofemoral nerve the foramen into a Exits through greater Piriformis Obturator nerve superior and inferior sciatic foramen Medial Lumbosacral trunk region B. Muscles of Pelvic Cavity Participating as Muscle of Lower Extremity Iliacus and Psoas (Iliapsoas) ○ Flexor of the thigh Obturator internus and Piriformis ○ Rotators of thigh Piriformis ○ Superior gluteal nerve will exit above the piriformis then to the sciatic foramen ○ Inferior gluteal nerve will exit below the piriformis then Figure 17. Medial Aspect of Pelvic Bone to the sciatic foramen VI. GLUTEAL REGION VI. LUMBOSACRAL PLEXUS(batch 2027) A. Surface Anatomy Lumbosacral plexus: L2 to S3 Sacral plexus: SIPS ○ Superior gluteal nerve: innervates gluteus medius, g. minimus, and tensor fasciae muscles ○ Inferior gluteal nerve: innervates gluteus maximus ○ Pudendal nerve: chief sensory nerve of external genitalia ○ ⭐ Sciatic nerve: innervates flexors of knee and thigh + all leg and foot muscles Exits through greater sciatic foramen Table 8. Nerves of the Lumbosacral Plexus Origin Nerve L2-4 Femoral Nerve L2-4 Obturator Nerve L4-5, S1-2 (Fibular) Sciatic Nerve L4-5, S1-3 (Tibial) L4-5, S1 Superior gluteal Nerve L5, S1-2 Inferior gluteal Nerve Figure 18. Surface anatomy of the gluteal region Iliac crest ○ Top of the ilium ○ Superior part of the pelvic bone ○ Demarcates the start of the gluteal region Gluteal fold Figure 16. Lumbosacral Plexus ○ Superior and inferior boundaries of the gluteal area Gluteal region Table 9. Structures in the Pelvic Cavity ○ Has two areas that are separated by an imaginary line Structure Location Exit (iliac crest - greater trochanter of the femur) Iliacus Located in iliac fossa Exits together as the Hip Psoas major Superior to the iliacus iliopsoas muscle ↪ Lateral part Divides anterior Buttocks Inguinal ↪ Medial part abdominal wall from – ligament lower extremities Page 6 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh Forms the iliotibial tract with gluteus *TG Note:Greater trochanter: readily palpated in the hips; maximus measured for anthropometric human measurements Medial rotation of thigh Stabilizes pelvis B. The Gluteal Muscles Deep Gluteal Muscles Table 13. Piriformis. PIRIFORMIS Landmark muscle ○ Determines the names of surrounding vessel and nerves ○ Anything above = superior; below = inferior Innervation Branches of anterior rami (S1 and S2) Inside pelvic cavity Location Exits in the greater sciatic foramen Attachment Greater trochanter Laterally rotates extended thigh Action Abducts flexed thigh Table 14. Obturator internus. OBTURATOR INTERNUS Innervation Nerve to obturator internus Inside pelvic cavity Location Exits in the lesser sciatic foramen Attachment Femur Laterally rotates extended thigh Action Abducts flexed thigh Table 15. Superior and inferior gemelli. SUPERIOR AND INFERIOR GEMELLI Figure 19. Gluteal muscles. Superior: nerve to obturator internus Innervation Inferior: nerve to quadratus femoris Superficial Gluteal Muscles Laterally rotates extended thigh Action Has proximal attachments to the external surface and Abducts flexed thigh margins of the ala of the ilium Table 16. Quadratus femoris. Table 10. Gluteus maximus. QUADRATUS FEMORIS GLUTEUS MAXIMUS Innervation Nerve to quadratus femoris Biggest, heaviest, and coarsest fibered muscle in the body Action Laterally rotates extended thigh Most superficial gluteal muscle Preferred site for intramuscular injection (esp. children) Gluteal Vessels Innervation Inferior gluteal nerve Named according to their location with respect to the Extension piriformis. Action ○ Pulls thigh posteriorly Lateral thigh rotation Table 17. Gluteal nerves. VESSELS NOTES Table 11. Gluteus medius and minimus. Superior to the piriformis GLUTEUS MINIMUS AND MEDIUS Runs laterally between the gluteus Gluteus minimus medius and minimus Most anterior “gluteus” Divides into superior and inferior Gluteus medius branches Superior gluteal Partially covered by the gluteus maximus ○ Superior: supplies the gluteus nerve Innervation Superior gluteal nerve medius Abduction ○ Inferior: pass between the Action Medial rotation of thigh When one leg is raised, the opposite gluteus medius and minimus muscles gluteus minimus and medius; Holds and stabilizes the pelvis work to stabilize pelvis supplies both and the tensor Location Anterior the gluteus maximus fascia latae Attachment Greater trochanter Inferior to the piriformis Enters the deep surface of the gluteus Inferior gluteal Table 12. Tensor fascia latae. maximus at its center nerve TENSOR FASCIA LATAE Supplied by both the inferior and Holds and stabilizes the pelvis superior gluteal arteries Innervation Superior gluteal nerve Abduction Action Stabilizes the knee during extension Page 7 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh Table 20. Pectineus PECTINEUS Flat quadrangular muscle located in the anterior part of the superomedial aspect of the thigh Major: Femoral nerve Innervation Minor: Obturator nerve Adduction Action Medial rotation at the hip joint Table 21. Sartorius SARTORIUS (Tailor) Figure 20. Gluteal vessels. Tailor’s muscle VII. THIGH Longest muscle of the body A. Compartments of the Thigh Cross-legged sitting (Indian Sit): Knee Flexion Table 18. Compartments of the thigh. ⭐ ○ Flexes the hip joint in the flexion of the knee joint ○ Shares the Pes Anserinus tendon with Gracilis and Movement Region Innervation Semitendinosus Thigh Knee Synergist Anterior Flexor Extensor Femoral nerve ○ Acts with other thigh muscles that produce movements Posterior Extensor Flexor Sciatic nerve due to its weak actions Medial Adductor Obturator nerve Origin Anterior superior iliac spine Attached to tibia via a tendon (pes Insertion anserinus) Attached to the pelvis over the hip joint Double flexion (thigh at hip and leg at Action knee) Table 22. Pes Anserinus ⭐ PES ANSERINUS flexes both the thigh and the knee Figure 21. Compartments of the thigh–axial plane. Muscles of the Anterior Compartment psoas is one of the deep posterior back muscles that rotate to the anterior of the pelvic region and attach to the femur Figure 23. Pes anserinus A. Contributing muscles. B. Converging tendons forming pes anserinus. Anterior: Sartorius Insertion Medial: Gracilis Posterior: Semitendinosus Medial side of the tibial tuberosity Figure 22. Muscles in the Anterior Compartment of Thigh. Attachment (proximomedial tibia) Table 19. Iliopsas Table 23. Quadriceps femoris ILIOPSOAS QUADRICEPS FEMORIS Main flexor of the thigh and hip joint (most powerful) Great extensor of the leg Bulk of the muscle is inside the abdominopelvic cavity. Most important muscle for knee stabilization ○ Small parts moving towards the thigh Primary responsible for shock absorbing of heel strike Does not contribute to knee extension Inserted into a single tendon (quadriceps tendon), enveloping Produces the most powerful hip flexors with the longest range the patella. Only muscle attached to the vertebral column, pelvis, and Bulk of the thigh muscles femur These muscles are inserted to a single tendon, quadriceps Location Pelvic Cavity tendon → which will envelop the patella → attached to the Flexion of the thigh tibia via patellar ligament Most powerful flexors: Action ○ Lateral part: Iliacus ○ Medial part: Psoas major Page 8 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh Figure 25. Muscles in the Medial Compartment. Table 23. Quadriceps femoris Figure 24. Four muscles of the Quadriceps Femoris Part Description Attachment Tibia via the patellar ligament Fan-shaped Flexion of the thigh Adductor longus Action Most anterior part of the adductor group Extension of the knee ⭐ Fan-triangular shaped 1. Rectus Femoris Adductor brevis Located deep to the pectineus and Origin: Anterior inferior iliac spine adductor group Action: Largest muscle of the medial ○ Steadies hip joint Adductor compartment ○ extends leg at knee joint magnus Most powerful and most posterior of the ○ helps iliopsoas to flex the thigh at adductor group the hip joint 2. Vastus lateralis Obturator Laterally rotate the thigh, steadies head Origin: Greater trochanter externus of acetabulum Parts Most superficial of the medial Action: Extension of knee joint; stabilizes patella compartment muscles 3. V. intermedius Most medial thigh muscle Origin: Anterolateral surface of femur Gracilis Weakest member of the adductor group Action: Extension of knee joint; Adducts the thigh, flex the knee, stabilizes patella medially rotate the leg 4. V. medialis Part of pes anserinus Origin: Intertrochanteric line Muscles of the Posterior Compartment Extensors of the thigh and flexors of the knee The Femoral Nerve Innervated by the sciatic nerve A small nerve only on the anterior side Main innervating nerve of the anterior compartment of the thigh. Located below the inguinal ligament, spreading into several branches. Figure 31. Muscles of the Posterior Compartment (“Hamstring”) Table 28. Muscles in the posterior compartment of the thigh HAMSTRING MUSCLES Semitendinosus Half tendon, half muscle Half membranous, half muscle Flattened membranous form Semimembranosus Sends a fibrous expansion which reinforce capsule of posterior knee joint called Figure 27. Innervations of the femoral nerve at the anterior compartment of oblique popliteal ligament the thigh. Long muscle in the posterior thigh Has two heads: long and short that is Muscles of the Medial Compartment Biceps femoris innervated by the tibial division of the Muscles of medial compartment are all adductors sciatic nerve and common Innervated by obturator nerve (L2, L3, L4) peroneal/fibular nerve respectively Page 9 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh B. Blood Supply ⭐Coming from the Abdominal Aorta ○ Arch of the aorta → Thoracic Aorta → Abdominal Aorta → Common Iliac Artery → Divides to Internal iliac artery, and External Iliac Artery Internal Iliac artery ○ Supply all organs in the pelvic cavity Small saphenous vein External iliac artery ○ Move out with the iliopsoas muscle into the thigh and become the femoral artery Figure 32. Popliteal Fossa - highlighted in green. ○ Will pass through the inguinal ligament to be called the femoral artery Table 29. Superficial boundary of popliteal fossa Structure Description Biceps femoris Superiorly and laterally Semimembranosus Superiorly and medially Gastrocnemius (lateral) Inferiorly and laterally Gastrocnemius (medial) Inferiorly and medially Skin and popliteal Posteriorly fascia REFERENCES Arturo M. Decano, MD, FPCS, FACS, FPSGS, FPSAi. Notes from Gluteal Region and Thigh. Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Figure 26. Course of the Aorta. Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins. Femoral artery femoral artery passes through the adductor hiatus to turn anteriorly and supplies the anterior part of the leg(?) Saphenous opening - defective opening of the fascia lata involving the femoral vein ○ Supply blood to the medial and anterior group Femoral Hernia ○ Once the iliac artery passed the inguinal - when organs not normally found in the femoral sheath (e.g. small intestines) enter the femoral sheath ligament, it is already called femoral artery Femoral Triangle - Inguinal ligament Profunda femoris artery profunda femoris artery supplies the thigh - Sartorius - Adductor Longus ○ Three to four perforating arteries pass through - Femoral Nerve adductor magnus muscle, winding around - Femoral Vein - Lymphatics femur to supply muscles in medial, posterior, Adductor Canal and lateral part of anterior compartments. - Bounded anteriorly by the sartorius (behind the sartorius) Study Course of Femoral Artery Shorthead of the biceps femoris is not an extensor of the thigh Figure 26. Vasculature of the thigh. C. The Popliteal Fossa Diamond shaped region containing: a. Popliteal artery: most medial b. Popliteal vein: middle c. Tibial vein: most lateral d. Common fibular nerve: comes from the sciatic nerve As the femoral artery passes posterior to the knee near the popliteal fossa, it is called the popliteal artery. Sciatic nerve divides into two: 1. Tibial nerve 2. Common fibular nerve Page 10 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh APPENDIX ANNEX A. Muscles of Gluteal Region: Abductors and Rotators of Thigh Page 11 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh ANNEX B. MUSCLES OF ANTERIOR THIGH ACTING AT HIP JOINT ANNEX C. MUSCLES OF ANTERIOR THIGH ACTING AT KNEE JOINT Page 12 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO  ANA 1.06 Gluteal Region and Thigh ANNEX D. MUSCLES OF MEDIAL THIGH ANNEX E. MUSCLES OF MEDIAL THIGH: EXTENSORS OF HIP AND FLEXORS OF KNEE Page 13 of 13 | TH: LAT, M. | ANA TG 3 | GOMEZ, HAYAG, LEE, A., LEE, J., LLAMES, LUCENO, MANALO