Hip Flexors

In human anatomy, the hip flexors are a group of skeletal muscles that act to flex the femur (thigh bone) onto the lumbo-pelvic complex, i.e., pull the knee upward.

The hip flexors are (in descending order of importance to the action of flexing the hip joint):

• Collectively known as the iliopsoas or inner hip muscles:
  • Psoas major
  • Psoas minor
  • Iliacus muscle

• Anterior compartment of thigh
  • Rectus femoris (part of the quadriceps muscle group)
  • Sartorius

• One of the gluteal muscles:
  • Tensor fasciae latae

• Medial compartment of thigh
  • Pectineus
  • Adductor longus
  • Adductor brevis
  • Gracilis

Without the iliopsoas muscles, flexion in sitting position is not possible across the horizontal plane.