How to stretch the back of your thighs. I'm Tanya Eberhardt and this is "How to Stretch the Back of the Thighs," The muscles of the back of the thigh are the hamstrings and they're very important to stretch, especially if you're a runner or you like to do the elliptical. Stretching will help prevent muscle spasms and keep your hamstring muscles healthy, happy and strong. Start with your toes together and heels slightly apart. Bring your hands to your hips, inhale, lift the chest and engage the abdominals, exhale, hands on your hips and bring your forehead towards the floor. Bring your hands to the outsides of your feet or the back of the calf, if you can't reach the floor. Slightly bend your knees and bring your chest and belly completely onto your thighs. Inhale to slowly straighten out your legs but keep your chest and your belly completely glued to your quadriceps. Inhale, exhale, contract your abdominals, contract your quadriceps and bring yourself into your legs. Inhale brings you all the way up with your abs contracted to protect your lower back. You want to hold uttanasana, the forward fold, for six long and deep breaths.