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Range of motion is a basic technique used for the examination of movement and for initiating movement into a program of therapeutic intervention. Movement that is necessary to accomplish functional activities can be viewed, in its simplest form, as muscles or external forces moving bones in various patterns or ranges of motions. When a person moves, the intricate control of the muscle activity that causes or controls the motion comes from the central nervous system. Bones move with respect to each other at the connecting joints. The structure of the joints, as well as the integrity and flexibility of the soft tissues that pass over the joints, affects the amount of motion that can occur between any two bones. The full motion possible is called the range of motion (ROM). When moving a segment through its ROM, all structures in the region are affected: muscles, joint surfaces, capsules, ligaments, fasciae, vessels, and nerves. ROM activities are most easily described in terms of joint range and muscle range. To describe joint range, terms such as flexion, extension, abduction, adduction, and rotation are used. Ranges of available joint motion are usually measured with a goniometer and recorded in degrees.16 Muscle range is related to the functional excursion of muscles.
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Functional excursion is the distance a muscle is capa ble of shortening after it has been elongated to its maximum.26 In some cases the functional excursion, or range of a muscle, is directly influenced by the joint it crosses. For example, the range for the brachialis muscle is limited by the range available at the elbow joint. This is true of one-joint muscles (muscles with their proximal and distal attachments on the bones on either side of one joint). For two-joint or multijoint muscles (those muscles that cross over two or more joints), their range goes beyond the limits of any one joint they cross. An example of a two-joint muscle functioning at the elbow is the biceps brachii muscle. If it contracts and moves the elbow into flexion and the forearm into supination while simultaneously moving the shoulder into flexion, it shortens to a point known as active insufficiency, where it can shorten no more. This is one end of its range. The muscle is lengthened full range by extending the elbow, pronating the forearm, and simultaneously extending the shoulder. When fully elongated, it is in a position known as passive insufficiency. Two-joint or multijoint muscles normally function in the midportion of their functional excursion, where ideal length-tension relations exist.26
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To maintain normal ROM, the segments must be moved through their available ranges periodically, whether it is the available joint range or muscle range. It is recognized that many factors, such as systemic, joint, neurological, or muscular diseases; surgical or traumatic insults; or simply inactivity or immobilization for any reason, can lead to decreased ROM. Therapeutically, ROM activities are administered to maintain ...