What is the effect of the working of the iliacus, psoas major, and rectus femoris muscles on the pelvis?

The iliacus, psoas major, and rectus femoris muscles all play a significant role in the movement and stabilization of the pelvis, specifically impacting pelvic tilt. When these muscles contract, they collectively contribute to an anterior pelvic tilt.

The iliacus and psoas major, which are hip flexors, attach from the lumbar spine and pelvis to the femur, pulling the femur upward and inward toward the body. This action creates a forward pull on the pelvis, resulting in an anterior tilt. The rectus femoris, as part of the quadriceps group, also assists in hip flexion while simultaneously extending the knee. When it contracts alongside the iliacus and psoas major, it helps further facilitate this forward tilt by maintaining an upright posture of the trunk and supporting the flexion at the hip.

This anterior pelvic tilt is essential in various movements such as walking, running, or sitting, where increased hip flexion is required. Understanding the impact of these muscles on the pelvis is crucial for assessing postural imbalances and developing appropriate therapeutic interventions in massage therapy and other forms of physical therapy.