differential relaxation
a technique for exerting only the amount of muscular tension or energy required to perform an activity successfully. For example, an individual driving an automobile can practice easing and releasing contracted muscles that are not primarily involved in the act of driving (e.g., the shoulders and upper back or the neck and facial muscles) and thus permit more appropriate focus and engagement of those muscles directly involved (e.g., in the hands, arms, legs, and lower back).