Range of motion (or ROM), is the distance (linear or angular) that a movable object may normally travel while properly attached to another object. It is also called range of travel, particularly when talking about mechanical devices and in mechanical engineering fields. For example, a volume knob may have a 300° range of travel from the "off" or muted position at lower left, going clockwise to its maximum-loudness position at lower right. As used in the biomedical and weightlifting communities, range of motion refers to the distance and direction a joint can move between the flexed position and the extended position...