This stretch is essential if you spend all day on your feet, or suffer from hip pain or sciatica. Start in hook-lying position: on your back with your knees bent and feet flat on the ground. On the side you want to stretch, turn your knee out, and cross your ankle across the opposite knee. Reach the arm on the stretch side through the triangle space between your legs and hold behind the knee of the opposite leg with both hands. To increase the stretch, lift the opposite side foot off the ground and bring that knee toward your chest.