Muscles of the Lower Limb

Anterior and medial muscles of the upper leg… …promote hip flexion, knee extension and leg adduction.

Posterior muscles of the upper leg… …promote hip extension and knee flexion.

Hip Flexors: -Iliopsoas -sartorius -tensor facia lata (TFL-ITB)*

Muscle: Origin Insertion Action Sartorius: Anterior superior iliac spine. Medial aspect of proximal tibia. Flexes, abducts, laterally rotates thigh. Iliopsoas: Iliac fossa and transverse processes of lumbar vertebrae. Lesser trochanter of the femur. Prime mover of thigh flexion. Tensor fascia lata: Anterior iliac crest and anterior superior iliac spine. Iliotibial tract (a.k.a. IT band) Steadies the knee and tightens the IT band.

Muscle: Origin Insertion Action Gluteus maximus: Dorsal ilium, sacrum, and coccyx. Gluteal tuberosity of the femur. Extends thigh. Gracilis: Inferior ramus of pubic bone. Inferior to the medial epicondyle of tibia. Adducts and medially rotates thigh. Adductor longus: Pubic bone (near symphysis) Linea aspera Adducts, flexes, and medially rotates thigh. Adductor magnus: Ischial tuberosity and pubic ramus.

Quadriceps: -Rectus femoris -Vastus Lateralis -Vastus medialis -Vastus intermedius

Muscle: Origin Insertion Action Rectus femoris: Anterior inferior iliac spine. Tibia tuberosity via the patellar ligament. Extends knee and flexes thigh. Vastus lateralis: Greater trochanter of femur. Extends and stabilizes knee. Vastus medialis: Linea aspera. Extends knee.

Hamstrings: -biceps femoris -semimembranosus -semitendinosus

Muscle: Origin Insertion Action Biceps femoris Ischial tuberosity and linea aspera. Lateral condyle of tibia and head of fibula. Extends thigh and flexes knee. Semimembranosus: Ischial tuberosity. Medial condyle of tibia. Semitendonosus: Medial aspect of proximal tibia shaft.

The above anatomical plate shows the relative thickness of each muscle group taken in cross-section. The majority of the girth of the upper leg is made of adductor and hamstring muscles.