You're going to need a water gun and a couple of pingpong balls and draw a finish-line with chalk. Have kids "push" the ball towards the finish line. Another great adaption is to use a straw in the bathtub, to push the ping pong around in the bath tub.
(This is a great idea from therapy fun zone, feel free to look around at other great ideas they have)
(This is a great idea from therapy fun zone, feel free to look around at other great ideas they have)