Throwing is a physical action which consists of mechanically accelerating a projectile and then releasing it into a ballistic trajectory, usually with the aim of impacting a distant target. This action typically refers to hand-throwing by animals with prehensile forelimbs. In this case, the projectile is grasped in a hand while the proximal limb segments move through compounded kinematic chains to impart a mechanical advantaged swinging motion. For other animals, the definition of throwing is somewhat unclear, as other actions such as spitting or spraying may or may not be included.