 Examples include a motor that aids or replaces original muscle tissue.Targeted muscle reinnervation (TMR) is a technique in which motor nerves, which previously controlled muscles on an amputated limb, are surgically rerouted such that they reinnervate a small region of a large, intact muscle, such as the pectoralis major.As a result, when a patient thinks about moving the thumb of his missing hand, a small area of muscle on his chest will contract instead.