Shoulders Exercises with Stability Ball
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.
Strengthen your shoulder muscles and reduce the change of injury (such as the rotator cuff) with the exercises found below.

A stability or exercise ball is a ball constructed of soft elastic and filled with air until firm.Most stability balls range from a diameter of approximately 35 to 85 centimeters (14 to 34 inches).
A primary benefit of exercising with an exercise ball as opposed to exercising directly on a hard flat surface is that the body has to respond to the instability of the ball in order to remain balanced. This in turn forces the body to engage far more stabilizing muscles (i.e. core muscles) and those muscles become stronger over time.
The stability ball is most often used during core (abdominal, lower back) strength exercises.
The reverse lunge with the overhead stability ball shoulder stretch is a dynamic warm-up exercise that is suitable for any fitness level.
Quadriceps & Shoulders Exercise
Equipment: Stability Ball