“From a research perspective, a lack of hip internal rotation has a direct correlation to low back pain,” Suarez says. Try these 6 hip stretches for lower-body mobilityThe hip is a complex joint with many stabilizing muscles as well as, of course, its prime movers. If you’re unable to fully extend at the top of the movement, Suarez says you’ll feel where your tightness is, whether it’s in the front hip (external rotation) or the back hip (internal rotation). Watch Seated Hip Internal Rotation:Suarez says many people will experience cramping as a result of this movement because they’re not accustomed to using their hip internal rotators, which get a lot of action here. Image: Stan Horaczek / Popular Science Stan HoraczekA slightly more advanced movement targeting the adductors of the inner thigh, this hip internal rotation exercise helps improve hip mobility.