Rehab exercises are used in helping correct improper muscle movement patterns and biomechanics. Biomechanics is the study of the mechanical laws relating to the movement or structure of living organisms (humans in this case). This means that there is a specific way your body should be moving to function at an optimal level.
By implementing rehab exercises, this will allow you to build a foundation of stability to help manage and keep you out of pain. Rehabilitative exercises should strengthen the musculature necessary to stabilize the area affected and improve your movement globally to not only get you out of pain, but keep you out of pain.