Had successful ACL surgery 2 years ago on left leg but it still feels weaker. Is there a good hamstring and quad strengthening program for that leg? I had a bad habit of masturbation. Sometimes I would do it 2-3 times a day. I used to do it vigorously. This went on for few years. Now my right arm feels weaker than my left. My right shoulder mass and size has decreased drastically. Any advice or suggestions?