If you spend long periods of time with your legs flexed at the hip (such as when sitting or cycling) and are experiencing stiffness or aching in your back, there is a chance that a tightening of your Psoas muscle (right) could be a contributing factor.

The muscle attaches the leg to the back and is responsible for flexing the hip.

It will adaptively shorten when in a flexed state for extended periods and because it attaches to the lower back, as it shortens it can pull on the spine which can in turn cause stiffness and pain.

In this short clip below, Sally demonstrates how to effectively stretch the Psoas to ease any tightness.