What is the Kinetic Chain?

 

 

Provided by American Council on Exercise

 

     The concept of the kinetic chain regarding anatomy has been around since 1955 when Dr. Arthur Steindler adapted the theory of Franz Reuleaux, a mechanical engineer.  Reuleaux proposed that a series of overlapping segments are connected via a pin joint, and these interlocking joints would create a system that allows movement of one joint to affect the movement of another joint within the kinetic link.  Dr. Steindler contended that the human body could be viewed the same way, as a system of rigid, overlapping segments connected by a series of joints, collectively referred to as the kinetic chain.  This idea proposed that movements occurring within each body segment would be capable of “closed-chain” or “open-chain” movement patterns.

     Anatomically, the kinetic chain describes the interrelated groups of body segments, connecting joints, and muscles working together to perform movements and the portion of the spine to which they connect. The upper kinetic chain consists of the fingers, wrists, forearms, elbows, upper arms, shoulders, shoulder blades, and spinal column. The lower kinetic chain includes the toes, feet, ankles, lower legs, knees, upper legs, hips, pelvis, and spine. In both chains, each joint is independently capable of a variety of movements. Dependent on whether the distal end of the chain is fixed or free to move without restriction, each movement is classified as either closed or open.

     A closed chain refers to a position where the most distal aspects of a given extremity are fixed to the earth or another solid object. This fixed position alters the movement of the joints and surrounding musculature up the chain. For example, if the feet are planted on the ground during a squat, the rest of the leg chain (i.e., ankles, knees, and hips) will move toward the fixed end of the extremity—the feet—as the body lowers into the squatting position. In contrast, an open chain refers to the distal end of an extremity moving freely in space—such as when performing a biceps curl with dumbbells or a seated leg extension on a weight machine—where the movement of the distal end of the extremity is not fixed.

     Closed-chain movements promote joint stabilization and have the potential to recruit more muscles and their associated joints. Further, closed-chain movements are transferable to many daily movements that involve more than one joint, which may lead to better neuromuscular coordination and overall joint health. Thus, many closed-chain exercises are considered “functional” and used in programming for functional training purposes [i.e., purposeful exercise that trains movement—not isolated muscle groups—and intentionally incorporates balance and body awareness (proprioception)].

     Open-chain movements, in contrast, involve more shearing forces at the involved joint compared to closed-chain movements and tend to recruit the musculature associated with only a single working joint in resistance training exercises like leg extensions and biceps curls.

Examples of closed-chain exercises include:

Notice that in each of the above exercises the distal end of the extremity is fixed, which results in the body moving about the fixed joint.

Examples of open-chain exercises include:

Notice that in each of the above exercises the distal end of the extremity is not fixed, and it moves about the body during the movement.

        As an exercise and health professional, it is important to recognize that good program design includes exercises that provide the most bang for the buck. Single-joint, open-chain exercises do have their place, such as in programs that isolate and strengthen a particular area of the body for aesthetic reasons (e.g., focused hypertrophy in body building) or improved function, such as in rehabilitative or pre-habilitative protocols. However, multi-joint, closed-chain exercises that focus on movement patterns that are transferrable to activities of daily living, recreation, and sport-specific activities may ultimately provide the most value to your clients.

 

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