Leg Muscles

Iliopsoas

Origin: Iliac fossa (iliacus part) and T12-L5 vertebrae (psoas major part); Insertion: Lesser trochanter of the femur; Action: Hip flexion.

Rectus Femoris

Origin: Anterior inferior iliac spine (AIIS) and ilium above acetabulum; Insertion: Tibial tuberosity via patellar ligament; Action: Knee extension and hip flexion.

Sartorius

Origin: Anterior superior iliac spine (ASIS); Insertion: Medial aspect of the tibia (part of pes anserinus); Action: Flexes, abducts, and laterally rotates the hip; flexes the knee.

Tensor Fasciae Latae (TFL)

Origin: Anterior aspect of iliac crest and ASIS; Insertion: Iliotibial tract to lateral condyle of the tibia; Action: Abducts, flexes, and internally rotates the hip.

Gluteus Maximus

Origin: Ilium, sacrum, and coccyx; Insertion: Gluteal tuberosity of the femur and iliotibial tract; Action: Extends and externally rotates the hip.

Biceps Femoris

Origin: Long head - ischial tuberosity; Short head - linea aspera of the femur; Insertion: Head of fibula and lateral condyle of tibia; Action: Knee flexion and hip extension (long head).

Gluteus Medius

Origin: Outer surface of the ilium; Insertion: Greater trochanter of the femur; Action: Abducts and medially rotates the hip.

Adductor Longus

Origin: Body of the pubis; Insertion: Middle third of the linea aspera of the femur; Action: Adducts and flexes the hip.

Gastrocnemius

Origin: Medial and lateral condyles of the femur; Insertion: Calcaneus via the Achilles tendon; Action: Plantar flexes the ankle and flexes the knee.

Soleus

Origin: Proximal tibia and fibula, and interosseous membrane; Insertion: Calcaneus via the Achilles tendon; Action: Plantar flexes the ankle.

Tibialis Anterior

Origin: Lateral condyle and upper two-thirds of the lateral surface of the tibia; Insertion: Medial cuneiform and first metatarsal; Action: Dorsiflexes and inverts the foot.