In case you're wondering what you're missing, check out this article from the NYTimes: The Art and Science of Wheelchair Basketball.

Chairs cannot move left or right, only forward and back. That makes defense a fascinating exercise of players’ positioning their wheels perpendicular to those of the ball carrier, allowing for more responsive movements.

Defense is Schulte’s strength. He can zip one way or another, stop and make half or full spins with such speed and precision that he and the player he is guarding look like synchronized swimmers. Beyond his 6-foot-5 arm span, he can perform the wheelchair player’s version of a jump — tilting his chair on one of its large wheels to reach a few inches higher and block a shot.