If your legs feel tight, the hip flexor stretch is a good stretch for people with back pain or who sit a lot. As Point Performance’s Chris Ricardo demonstrates, the stretch helps stretch the front of the thigh. It’s a common stretch, although can be done incorrectly. Arching your back is one way that can make the stretch less effective.
Make sure to keep back straight and can even squeeze the glute for an extra stretch. Progressing the exercise is having one foot on a stool to maximize the stretch.