Why do my hips lock completely up from sitting in odd hyper-mobile positions?
1. Introduction Hips locking up after sitting in odd, hyper-mobile positions is caused by a combination of severe muscle spasm, ligament laxity, and transient joint subluxation. When the hip is held at extreme end-ranges of motion, the stabilizing ligaments become overstretched, forcing the surrounding deep musculature to aggressively contract and spasm to prevent the joint … Read more