🚨 TRUTH ABOUT YOUR HIPFLEXOR
✅ The psoas is often blamed for a lot of problems when we’re not sure of its true functions. One of the common theories is that the psoas causes anterior pelvic tilt by pulling on the lumbar spine, however in a few bio mechanics’ studies (N Bogduk et.al Clin biomech 1992) the psoas is shown not to be a prime mover of the lumbar spine, rather it solely evolved to be a primary hip flexor. Because of its position and the length of the fascicles that attached to the lumbar spine some parts of the psoas will pull the spine into extension while others into flexion, however even those forces as calculated by the researches are not enough to cause the movement at the spine.
✅Other researches (L. Penning Eur Spine J 2000) looked at the possibility of the psoas to perform a stabilizing function on the lumbar spine, citing the same length of fascicles of the psoas, which would adapt to the different degrees of lordosis in the spine. This is further supported by (Hai Hu et.al eur spine j 2011) which looked at the psoas activity during SLR, finding the contralateral psoas activating during the leg raise concluding its possibility as a lumbar stabilizer when activated bilaterally. This was also concluded in a study by (P.L. Santaguida and S. M. McGill 1995) citing the line of pull of the psoas acted as a guy wire would for a tower stabilizing the spine laterally.
✅We can see the complexity and misunderstanding behind this muscles function, taking this information as preliminary it should still add caution to the way we see the psoas. It is a muscle that should not be blamed for many issues. If you feel tight in the hips try the Thomas test, it will tell you if your hip flexors or quads are tight and can give you some more insight on what the issue is. If your leg remains elevated and knee extended, it is most likely your rectus femoirs, so a bent knee stretch should help you. However it if your knee hangs at 90 degrees but leg remains elevated it may be your deep hip flexors that are tight.