The motor system includes the components of the central and peripheral nervous system along with the muscles, joints and bones that enable movement. Motor control is the study of how body movements are planned by the brain and performed by the body. Woodworth stated that there were two phases: an impulse phase in which the brain calculates the necessary movements and a control phase where vision is the key to accuracy.The degrees of freedom of a joint is the number of ways it can move. The degrees of freedom problem refers to the choice of how to move the body when there are countless possible ways to do so. There are several theories of movement planning:Equilibrium point hypothesis (mass-spring model)This is a theory of motor control that emphasizes how the problem of control can be simplified by taking into account muscle properties. The muscle tension determines the movement. If one muscle increases tension, another muscle decreases tension (because most muscles are arranged in an agonist/antagonist system) and this causes the correct movement.Dynamical systemsMuscles and joints work together in a certain way. Movement is determined by the physical properties of the body (e.g: the difference between walking and running is determined by speed and transitions automatically). The dynamical systems cause movement to be performed correctly.Optimal control theoryThis is a theory of motor control that states that movement that is the most efficient and the most optimal is selected. The most efficient movement is the movement that causes the least amount of torque change at the joints. This system uses forward models. This predicts the relationship between actions and their consequences. The body tries to predict sensory feedback (e.g: we can type relatively quickly and this wouldn’t be possible if we didn’t predict feedback, because we move too quickly to first process it and then act according to the perceived feedback). The control...