What are kinetics in relation to body motion?

Kinetics is specifically concerned with how forces influence motion. It examines the relationship between the motion of objects and the forces acting upon them. In the context of body motion, this means understanding how different forces—such as those generated by muscles, gravity, and external stimuli—affect the way the body moves. Kinetics is crucial in fields such as biomechanics and physical therapy, where understanding these forces can help practitioners design effective treatment and rehabilitation plans.

In contrast, the other options focus on different aspects of body mechanics: the study of muscle tissue is associated with histology and physiology, the analysis of joint angles pertains to kinematics, which is concerned with the motion of the body without reference to the forces that cause it, and the effects of gravity on posture relates more to postural analysis than to kinetics itself. Therefore, the emphasis on forces in option B accurately captures the essence of kinetics in relation to body motion.