This blog post contains the cited research references for the eleven-part blog post series on Psoas Major Function that is found on Learnmuscles.com.
Looking at the psoas major from a biomechanical perspective might be the key to understanding this elusive and controversial muscle.
The psoas major’s has extensive fascial connections. The psoas major is part of the deep front line myofascial meridian (anatomy train).
The psoas major crosses the hip and spinal joints. However, it is often overlooked that the psoas major also crosses the sacroiliac joint.
A healthy joint is both mobile and stable. However, some sources are concerned about the psoas major’s compression/stabilization effect upon the spine.
The psoas major’s sagittal plane lumbar spine joint action is by far its most controversial function. The term “psoas paradox” describes this controversy.
The frontal plane spinal action of the psoas major is fairly clear; it crosses the spinal joints laterally, so it lateral flexes the spine to that side.
The function of the psoas major has been claimed to be both medial rotation and lateral rotation. However, most sources agree that it is a lateral rotator.
If the psoas major frontal plane open-chain action is abduction of the thigh at the hip joint, the closed-chain action is depression of the pelvis.
Note: This is the third blog post article in a series of 11 articles on Psoas Major Function. See below for the other articles in this series on psoas major function. The hip joint is a triaxial joint that allows …
The psoas major is first and foremost, a muscle of the hip joint; however it is more complicated because it also crosses the spinal joints.
The Psoas Major may hold the distinction of being the most important as well as the most misunderstood muscle in the human body.