The psoas is a key player in almost everything! A muscle that crosses three zones (lumbar spine, pelvis, hip) it is therefore crucial to stability. The primary role of the psoas is lumbar spine stabilisation and hip flexion, but very often it can become tight and weak… why? SITTING. When sitting, the psoas is in a chronically shortened position, and then when we stand, the shortened psoas alters the alignment of the spine and hips. The quadratus lumborum (QL) works overtime to try and balance the equation by trying to achieve a neutral spine. The result.. Loss of range of