Stand with side of body facing wall. Position feet wider than shoulder's width apart with knees and hips slightly bent. With both hands, hold medicine ball to front side of hip furthest from wall.
Rotate body while extending and rotating foot furthest from wall so far leg turns toward wall with foot extended. At same time, rapidly extend arms upward toward wall. Throw ball against wall at slightly upward angle. Catch ball on rebound. Turn body to original position and return medicine ball to far side of hip. Immediately repeat movement.
Perform prescribed repetitions or for time. See Spot Reduction Myth regarding spinal rotation.