Do you have a day job that requires to sit all day long? If the answer to this question is yes you might be suffering from LPHC (Lumbar-Pelvic Hip Complex) dysfunction. Sitting for long extended periods of time can cause your hip flexor muscles to flex which causes them to become overly tight. This also can cause your glute muscles to become weaker causing a muscle imbalance which leads to back and hip pain. There is an easy fix and can be corrected by fixing your posture, getting up several times throughout the day and stretching.
If you are interested in learning some stretches to help correct this and learn some deeper information please see this blog