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. Back (upper) You can’t see your back without a lot of effort, but this doesn't mean you shouldn’t train it. Back exercises consisting of both back stretching and back strengthening is very important to your health and overcoming back pain. Equipment Used Resistance Band n/a Exercise Instructions Step 1 Start in a standing position while holding an exercise band in each hand. Step 2 Keep your arms straight and spread the band apart as you lift it over your head. Step 3 Continue all the way over until the band touches your butt and then return to the starting position.