WHEELCHAIR BASKETBALL has been part of the Summer Paralympics since 1960. At the London 2012 Paralympics, 144 men and 120 women will be competing in two medal events at the Basketball Arena and North Greenwich Arena in Olympic Park from August 30 through September 8. Classifications in Wheelchair Basketball are assigned in the form of a point value of 1.0 to 4.5 to indicate a player's degree of functional ability, least to most, and the total on the floor at any time for any one team can't be more than 14. There are two competitions, one for men and one for women.
According to the description on the site of the 2012 London Summer Paralympics, "The rules of Wheelchair Basketball are broadly similar to Basketball. The court is the same size, the basket is at the same height, and the scoring is identical: two points for a regular shot from open play, one point for each successful free throw and three points for a shot from distance (6.75m from the basket). Players move the ball around the court by passing or dribbling, and are required to throw or bounce the ball after every two pushes of the wheels on their chairs to avoid being penalised for travelling."
You can read more about Paralympic Wheelchair Basketball on the site of the International Paralympic Committee.