Step by Step Guide
Begin lying on your stomach on a mat propped up onto your forearms (spinx pose). Bend one leg up bringing the foot toward your buttocks.
Reach back with your hand on that side of the bent leg to grab your foot and assist to deepen the stretch by pulling the foot toward your buttocks even further.
Hold for about 30-seconds. Keep the torso upright and chest open by engaging the scapula on the other side.
Relax and repeat on the other side.
A common mistake is not keeping the hips extended - pushing down into the mat. If you allow the hips to flex (as they naturally want to) and raise up off the mat, you are no longer fully lengthening those hip flexors. So squeeze the glutes, and press the pubic and pelvis bones down into the mat the entire time.