* I recommend straight leg raises to strengthen the thigh muscles and protect the knee against injury. To do them, lie on the floor on your back, one knee bent, the other straight, hands palm-down under the buttocks to support the low back. Contract the quadriceps on the straight leg, then raise the leg to the height of the other knee. Pause one to two seconds at the top, then lower the leg but do not allow it to touch the floor. Repeat 10-15 reps, three sets. You can use ankle weights if these are very easy. Start with one pound and work up. You should always be able to do 10-15 reps. As you get stronger, you can progress to leg extensions, leg curls, leg presses, squats, and other leg exercises.