Muscles of the Anterior Thigh

Muscles of the Anterior Thigh (Inguinal ligament) (and other important landmarks) Iliacus Psoas major Iliopsoas: 1) Iliacus 2) Psoas major Pectineus Tensor fasciae lata Adductor brevis (deep beneath pectineus) Adductor longus Gracilus (Iliotibial tract) Adductor magnus Sartorius Rectus femoris Vastus lateralis Vastus intermedius (deep to rectus femoris) Vastus medialis Quadriceps femoris: 1) Vastus lateralis 2) Rectus femoris 3) Vastus medialis 4) Vastus intermedius (deep to Rectus femoris) (Patella) The Muscles Crossing the Hip and Knee Joints (Anterior View) 1 l. Anterior Medial (Pelvic) Muscles 13 Iliopsoas: two-muscle complex: Iliacus and Psoas major 6 (deep) 2 7 1) Iliacus a. Actions: hip flexion b. Innervation: Femoral nerve c. Origin: from iliac fossa d. Insertion: to lesser trochanter of femur 3 5 8 2) Psoas major a. Actions: hip flexion, lateral flexion of vertebral column (posture) b. Innervation: Femoral nerve c. Origin: from transverse processes and bodies of lumbar vertebrae 4 9 d. Insertion: to lesser trochanter of femur 3) Sartorius a. Actions: hip flexion, laterally rotates thigh, weakly flexes knee (sitting cross-legged) b. Innervation: Femoral nerve c. Origin: from anterior superior iliac spine wind medially around thigh d. Insertion: to medial aspect of proximal tibia 10 12 (deep to rectus femoris) 11 The Muscles Crossing the Hip and Knee Joints (Anterior View) Continued... ll. Muscles of Medial Compartment of Thigh 4) Adductor magnus a. Actions: anteriorly it adducts, laterally rotates and flexes thigh (at hip), posteriorly it aids hamstrings in extension b. Innervation: Obturator nerve and Sciatic nerve c. Origin: from ischial and pubic rami and ischial tuberosity d. Insertion: to linea aspera 1 13 2 7 3 5) Adductor longus a. Actions: adducts and laterally rotates thigh (at hip) b. Innervation: Obturator nerve c. Origin: from pubic symphysis d. Insertion: to linea aspera (above magnus) 8) Gracilis a. Actions: adducts, flexes and medially rotates thigh (at hip) – especially while walking b. Innervation: Obturator nerve c. Origin: from pubis d. Insertion: to medial tibia inferior to tibial head 5 8 4 6) Adductor brevis (deep - not see here) a. Actions: adducts and laterally rotates thigh (at hip) b. Innervation: Obturator nerve c. Origin: from ramus of pubis d. Insertion: to linea aspera (above longus) 7) Pectineus a. Actions: adducts, flexes and laterally rotates thigh (at hip) b. Innervation: Femoral nerve and Obturator nerve c. Origin: from pubis d. Insertion: to wrap around lesser trochanter of femur (posterior) 6 (deep) 9 10 12 (deep to rectus femoris) 11 The Muscles Crossing the Hip and Knee Joints (Anterior View) Continued... lll. Muscles of Anterior Compartment of Thigh Quadratus femoris: four-muscle complex: Rectus femoris, Vastus lateralis, Vastus medialis, Vastus intermedius 9) Rectus femoris a. Actions: extends knee, flexes at hip b. Innervation: Femoral nerve c. Origin: from anterior inferior iliac spine d. Insertion: to tibial tuberosity (via the patellar tendon) 1 13 2 7 10) Vastus lateralis a. Actions: extends knee b. Innervation: Femoral nerve c. Origin: from greater trochanter of femur and linea aspera d. Insertion: to tibial tuberosity 3 4 c. Origin: from linea aspera d. Insertion: to tibial tuberosity 9 12) Vastus intermedius (deep - not see here) a. Actions: extends knee b. Innervation: Femoral nerve c. Origin: from anterior and lateral shaft of proximal femur d. Insertion: to tibial tuberosity * The iliotibial tract is a thickened lateral portion of the fascia that sheaths the muscles of the thigh and runs from the iliac crest to the knee. 5 8 11) Vastus medialis a. Actions: extends knee, stabilized patella b. Innervation: Femoral nerve 13) Tensor fasciae latae a. Actions: flexes and abducts thigh (at hip) b. Innervation: Superior gluteal nerve c. Origin: from iliac crest and anterior superficial spine d. Insertion: to the iliotibial tract* 6 (deep) 10 12 (deep to rectus femoris) 11