Muscles of the thigh

Objectives Know the type and formation of hip joint. Differentiate the stability and mobility between the hip joint and shoulder joint. Identify the muscles that act at the hip joint. Identify the muscles of the thigh in terms of their origin, insertion, nerve supply and actions. Explain the relationships of contents of the femoral triangle to each other & to the surrounding bone and soft tissue landmarks.

Surface anatomy of the thigh Surface features of the Thigh Sartorius muscle Quadriceps femoris muscle Adductor longus muscle Hamstring muscles Femoral triangle

Compartments of the thigh Thigh is divided to 3 groups of muscles called compartments. Anterior compartment Posterior compartment Medial compartment

Posterior Compartment The thigh is divided into 3 compartments by 3 intermuscular septa (extending from deep fascia into femur) Anterior Compartment Extensors of knee: Quadriceps femoris Flexors of hip: 1. Sartorius 2. Pectineus 3. psoas major 4. Iliacus Nerve supply: Femoral nerve Medial Compartment Adductors of hip: 1. Adductor longus 2. Adductor brevis 3. Adductor magnus (adductor part) 4. Gracilis Nerve supply: Obturator nerve Posterior Compartment Flexors of knee & extensors of hip: Hamstrings Nerve supply: Sciatic nerve

Medial Compartment of Thigh MUSCLES: Adductor longus Adductor brevis Adductor magnus (Adductor portion) Gracilis ACTION: ADDUCTION OF HIP JOINT N.B.: Gracilis also flexes knee joint NERVE SUPPLY: OBTURATOR NERVE 1 2 2 1 4 3 3 4 Adductor magnus (Adductor portion) Adductor magnus (Hamstring portions)

Origin Insertion Inferior pubic ramus Ischial ramus Body of pubis Adductor part Hamstring hiatus Adductor hiatus Adductor magnus (adductor portion) Gracilis Adductor longus Adductor brevis Insertion Upper part of medial surface of tibia (behind sartorius) Posterior border of femur (Linea Aspera)

Medial Compartment

Medial Compartment Obturator artery: Blood Supply: Branch of internal iliac artery.

Medial Compartment Innervation: Obturator nerve. Action: Adduction Tibial nerve: To hamstring portion of adductor magnus. Action: Adduction

Anterior Compartment of Thigh Contains the: Flexor of the hip: Sartorius Pectineus Psoas major Iliacus Extensors of knee (Quadriceps femoris): Rectus femoris Vastus lateralis Vastus medialis Vastus intermedius (deep to rectus femoris) Nerve supply: Femoral nerve 4 3 2 1 2 1 4 Vastus Intermedius (deep to rectus femoris) 3

Sartorius Action (TAILOR’S POSITION) Flexion, abduction & lateral rotation of hip joint Flexion of knee joint S

Pectineus ACTION: Flexion & adduction of hip joint

Iliacus & Psoas major (Iliopsoas) Origin: Psoas major: T12 & lumbar vertebrae Iliacus: Iliac fossa Action: Flexion of hip joint Insertion: Lesser trochanter of femur

Quadriceps Femoris Vastus medialis: Posterior border of femur Origin: Rectus femoris: Anterior inferior iliac spine Vastus intermedius: Front of shaft of femur Vastus medialis: Posterior border of femur Vastus lateralis:

INSERTION: Into PATELLA (Patella is a sesamoid bone) From patella into TUBEROSITY OF TIBIA through Ligamentum Patellae (Patellar Ligament) ACTION: Extension of knee joint

Anterior Compartment Blood Supply: Femoral Artery: Superficial circumflex iliac. Superficial epigastric. Superficial external pudendal. Deep external pudendal. Descending genicular. Deep femoral (profunda femoris) Lateral femoral circumflex. Medial femoral circumflex.

Anterior Compartment Innervation: Femoral Nerve: Action: Hip flexion. Knee extension.

Femoral Triangle: Location & Boundaries It is a deep hollow in the Upper third of front of thigh inferior to the inguinal ligament Boundaries Base: Inguinal ligament Medial: Medial border of the adductor longus muscle Lateral: Medial border of the sartorius muscle Floor: (from media to lateral) adductor longus Pectineus Psoas major Iliacus Roof: Skin, superficial & deep fascia. Iliopsoas Pectineus

Femoral Triangle: Contents From lateral to medial: Femoral nerve & its branches Femoral artery Femoral vein Lymphatic vessels and some deep inguinal lymph nodes Great saphenous vein (superficial), draining into femoral vein

ADDUCTOR CANAL (Subsartorial/Hunter’s canal) Adductor hiatus DEFINITION: an aponeurotic tunnel for femoral artery & vein SITE: In middle third of front of thigh deep to sartorius EXTENT: From apex of femoral triangle to adductor hiatus BOUNDARIES: Roof (Anterior): Sartorius (medially) and vastus medialis (laterally) Floor (Posterior): Adductor longus & magnus

Posterior Compartment Of The Thigh Muscles: Hamstring muscles: Biceps femoris. Semitendinosus. Semimembranosus. Ischial part of adductor magnus. Blood supply: Branches of the profunda femoris artery. Nerve supply: Sciatic nerve.

Biceps Femoris Origin: The long head from the ischial tuberosity. The short head from the linea aspera . Insertion: Into the head of the fibula. Nerve supply: The long head is supplied by the tibial part of the sciatic; the short head is supplied by the common peroneal part of the sciatic. Action : Flexion of knee. Lateral rotation of flexed leg. Long head: extends hip.

Semitendinosus Origin: Ischial tuberosity. Insertion: Upper part of the medial surface of the shaft of the tibia (SGS).. Nerve supply: Tibial portion of the sciatic. Action: Flexes and medially rotates the leg at the knee joint; Extends the thigh at the hip joint.

Semimembranosus Origin: Ischial tuberosity. Insertion: Posterior surface of the medial condyle of the tibia. It forms the oblique popliteal ligament, which reinforces the capsule on the back of the knee joint. Nerve supply: Tibial portion of the sciatic nerve. Action: Flexes and medially rotates the leg at the knee joint; Extends the thigh at the hip.

Adductor Magnus (Hamstring Part) Origin: Ischial ramus and ischial tuberosity Insertion: Adductor tubercle of the medial condyle of the femur. Nerve supply: The tibial portion of the sciatic. Action: Extends the thigh at the hip joint.

Posterior compartment of the thigh Innervation: Tibial division of sciatic nerve Except short head of biceps femoris: common fibular division of sciatic nerve posterior

BLOOD SUPPLY The four perforating branches of the profunda femoris artery provide a rich blood supply to this compartment. The profunda femoris vein drains the greater part of the blood from the compartment.

Sciatic Nerve NERVE SUPPLY The sciatic nerve, a branch of the sacral plexus (L4 and 5; S1, 2, and 3), leaves the gluteal region as it descends in the midline of the thigh. It is overlapped posteriorly by the adjacent margins of the biceps femoris and semimembranosus muscles. It lies on the posterior aspect of the adductor magnus. In the lower third of the thigh it ends by dividing into the tibial and common peroneal nerves.

Tensor Fascia Latae Psoas Major Iliacus Rectus Femoris Vastus Intermedius DEEP TO RECTUS FEMORIS Adductor Longus Vastus Lateralis Sartorius Vastus Medialis