hip flexors O/I/N/A

Iliopsoas: Origin

Psoas Major: T12-L5 bodies & transverse processes. Iliacus: Iliac fossa.

Iliopsoas: Insertion

Lesser trochanter of femur.

Iliopsoas: Innervation & Nerve Roots

Psoas: Ventral rami L1-L3. Iliacus: Femoral nerve (L2-L4).

Iliopsoas: Primary Action

Primary Hip Flexor.

Iliopsoas: Secondary Actions

Pelvic-on-femoral anterior pelvic tilt; weak external rotator in anatomical position.

Iliopsoas: Clinical & Biomechanical Notes

Passes over superior pubic ramus (clicking); shortens in hip swelling (lowest pressure at 30-40° flexion).

Rectus Femoris: Origin

Anterior Inferior Iliac Spine (AIIS) & superior acetabular rim.

Rectus Femoris: Insertion

Tibial tuberosity (via patellar tendon).

Rectus Femoris: Innervation

Femoral nerve (L2-L4).

Rectus Femoris: Primary Actions

Hip Flexion & Knee Extension.

Rectus Femoris: Biomechanical Feature

Bi-articular quadriceps requiring Rectus Abdominis co-activation during leg raises to prevent anterior pelvic tilt

Tensor Fasciae Latae (TFL): Origin

Outer surface of iliac crest, posterior to ASIS.

Tensor Fasciae Latae (TFL): Insertion

Proximal 1/3 of Iliotibial (IT) band (attaches to Gerdy's tubercle).

Tensor Fasciae Latae (TFL): Innervation

Superior Gluteal nerve (L4-S1).

Tensor Fasciae Latae (TFL): Primary Actions

Hip Abduction, Flexion, & Internal Rotation

Tensor Fasciae Latae (TFL) stabilizes...

Tenses IT band to stabilize extended knee; tightness increases

Tensor Fasciae Latae (TFL) tightness increases...

lateral knee stress

Sartorius: Origin

Anterior Superior Iliac Spine (ASIS).

Sartorius: Insertion

Proximal medial tibia (Pes Anserinus).

Sartorius: Innervation

Femoral nerve (L2-L3).

Sartorius: Actions at Hip & Knee

Hip: Flexion, Abduction, External Rotation. Knee: Flexion, weak tibial internal rotation.

Sartorius: Key Anatomical Features

Longest muscle in the body; bi-articular; does not attach directly to the femur.