Kinematics of Arm Joint Motions in Basketball Shooting

A basketball shooting arm model is used to estimate arm joint motions for a set of desired release speed, angle and backspin. The model has three rigid planar links with rotational joints imitating an upper arm, forearm and hand with shoulder, elbow and wrist joints. The kinematics of the shooting arm is solved to calculate the joint angles, and the velocity and angular velocity of links at release. There are many angular displacement and velocity combinations of shoulder, elbow and wrist joints to produce the optimal release speed, angle and backspin of the ball at release. Shoulder rotation contributes to the vertical component of release velocity of the ball and elbow and wrist actions mostly produce the horizontal component of release velocity and backspin of the ball when the forearm and hand are nearly vertical at release.