MUSCLES ENGAGED Shoulders The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well. Quadriceps The quadriceps (quads) are a group of four muscles on the front of the thigh. They allow your knee to straighten and provide stability when standing. Your quads are the most important muscle group for maintaining the ability to stand and to walk independently. Equipment Used Skipping Rope Skipping rope is a low impact, aerobic exercise. In contrast to running, jumping rope is unlikely to lead to knee damage since the impact of each jump or step is absorbed by the balls of both feet rather than the heels which greatly decreases the ground reaction forces through the patella-femoral joint. Exercise Instructions Step 1 Hold the rope in both hands. Step 2 Skip for the recommended amount of time. Step 3 Try not to lift your feet too high off the ground when jumping over the rope.