Team control of the ball is determined by the player who has control of the ball. In some situations, players from opposing teams may control the ball at the same time. This results in a held ball.
Held balls frequently occur when one player is carrying the ball, usually on the lap, and an opposing player is able to place a hand firmly on the ball, preventing the first player from being able to move it. A held ball may also called if the ball becomes trapped under a wheelchair or between two wheelchairs, or if two or more opposing players simultaneously cause the ball to go out-of-bounds.
When a held ball occurs, the referee will blow his whistle and indicate the held ball by raising both arms in the air, fists clenched and thumbs extended upwards. Possession after a held ball is determined according to the alternating process. Once the ball has become live after a held ball, the scorekeeper will change the direction of the alternating possession arrow.