Stand up straight holding the handle of a medicine ball in your hand to be exercised.
Stand with your back to the wall, then rotate yourself slightly towards the medicine ball.
Lift your arm out to your side with your elbow bent to 90 degrees.
The back of your elbow should rest against the wall with your forearm facing toward the floor.
With your neck long, rotate your forearm upwards quickly, slamming the ball against the wall.
Control the movement as you return your forearm back to the starting position, and then repeat.
Ensure your body stays in the same position, with your neck long and trunk square.
Tighten your abdominal muscles during the movement to hold your body in position.
