In order to prevent knee injuries, a person must strengthen all of the muscles around the knee, such as the quadriceps, the hamstrings and the calf muscle. Discover exercises for strengthening a number of muscles around the knee withhelp from a certified personal trainer in this free video on preventing knee injuries. Expert: Tanya Batts Bio: Tanya Batts has been a certified personal fitness trainer for more than 11 years. She specializes in Pilates, yoga, combat...