Hip Flexor Stretch - A: Start on knees. Bring left leg to a bent-knee position with left foot flat on the floor and right foot behind you. (If you have knee problems, put a pillow under right knee.) B: Place right hand on waist and left hand on left leg for support. Lean forward into right hip while keeping right knee on the floor. You should feel the stretch in the front of right hip. Hold for 30 seconds; switch sides and repeat.