Hamstring curls strengthen the muscles in the back of the thigh. Do 8 to 12 repetitions.

• Lie on your stomach with your knees straight. If your kneecap is uncomfortable, roll up a washcloth and put it under your leg just above your kneecap.
• Lift the foot of your injured leg by bending the knee so that you bring the foot up toward your buttocks. If this motion hurts, try it without bending your knee quite as far, in order to avoid any painful motion.
• You may also want to add a cuff weight to your ankle (not more than 5 pounds), or use soup cans in a plastic bag with the loops around your ankle. With weight, you don't have to lift your leg more than 12 inches to get a hamstring workout.