Stretching: The Truth You’re doing it wrong. Here’s the “scorpion” (for the lower back, hip flexors and gluteus muscles): Lie on your stomach, with your arms outstretched and your feet flexed so that only your toes are touching the ground. Kick your right foot toward your left arm, then kick your left foot toward your right arm. Since this is an advanced exercise, begin slowly, and repeat up to 12 times.