Tennis is a competitive recreational activity in which participants hit a tennis ball back and forth over a net and attempt to outplay their opponent by placing the ball in strategic areas of the court. There are two versions of tennis within disability sport - ambulatory tennis and wheelchair tennis. See the new NCHPAD video-enabled factsheet on wheelchair tennis at http://www.ncpad.org/37/291/Wheelchair~Tennis, as well as an additional NCHPAD factsheet on adapted table tennis (http://www.ncpad.org/843/205/Table~Tennis).