Towel Hamstring Stretch Lie on the back, supporting the thigh with the hand or with a towel wrapped around it.. Slowly straighten the knee until a stretch is felt in the back of the thigh, trying to get the bottom of the foot to face the ceiling, one leg at a time. Hold the position initially for 10 seconds, and gradually work up to 20 to 30 seconds. Seated Hamstring Stretch While sitting at the edge of a chair, straighten one leg in front of the body with the heel on the floor. Then, sit up straight and try pushing the navel towards the thigh without leaning the trunk of the body forwards. Hold this stretch for 30 seconds Repeat 3 times for each leg.