P&P#60

P&P #60: Open-Closed Chain Reactions

The following response from Stephen Perle sheds further valuable light on the whole tradition of open-closed chain actions. It is useful in that it stresses that the original definition of Closed vs Open chain by Steindler DID NOT refer to predetermined, restrained or cyclic actions vs unrestrained, non-repeated, 'functional' or acyclic actions in many dimensions.

This makes the important point that many original definitions or concepts are re-interpreted, misinterpreted or misapplied by series of users who may not have seen the original definition or may not fully appreciate all the nuances or idiosyncracies inherent in the original. This is not to state categorically that the original is either right or wrong - it means that the critic is using his or her own definition or rendition of the same.

In an earlier P&P we discussed the imprecision inherent in stating (incorrectly) that Newton stated that his 2nd Law is given by the equation : Force = Mass x acceleration. The closed-open saga is similar, but worse in that it is even more subject to opinion and personal interpretation than any of Newton's Laws.

Please note that Steindler's definition is by no means the final word in this matter, even though he has propriety rights to the original application of such terminology in sports science. We still need to re-examine the value, use and relevance of such classification - and thus far, nobody has put forward a convincing case for the validity and value of this closed vs open chain classification in human movement systems.

"Stephen Perle, DC" (perle@cse.bridgeport.edu) commented:

The concept of closed chain exercise and the definition that Dr. Siff gave is a paraphrase of the definition from Arthur Steindler, MD who it appears to have coined the term in his book Kinesiology of the Human Body Under Normal and Pathological Conditions. Springfield: IL, 1955.

Dr. Steindler wrote:

"We designate an open kinetic chain a combination in which the terminal joint is free. The waving of the hand is an open kinetic chain in which the action of the shoulder joint, the elbow joint, and the wrist joint are successively involved.

A closed kinetic chain, on the other hand, is one in which the terminal joint meets with some considerable external resistance which prohibits or restrains it free motion. Eventually, the external resistance may be overcome and the peripheral portion of the joint may move against this resistance, for instance, in pushing a cart or lifting a load; or the external resistance is absolute, in which case the proximal part moves against the peripheral, as for instance, in chinning oneself on a horizontal bar; or the limitations of the muscular effort may assert itself both peripherally and proximally and may be unsurmountable, in which case no visible motion is produced. Only in the latter instance is the kinetic chain strictly and absolutely closed.

However in common use we apply the term to all situations in which the peripheral joint of the chain meets with overwhelming external resistance."

One will note that Dr. Steindler presents some of the same problems inherent in his own definition that Dr. Siff noted in his posting. Dr.Steindler allows that eventually moving a great external force still would be classified as a closed chain exercise. Thus, one would suppose that the use of an isokinetic dynamometer at slow speeds should also be considered to be a closed chain exercise. However, a MedLine search of the literature (done two years ago) found that the all the experimental studies that dealt with open vs closed chain exercise were contrasting the use of isokinetic dynamometer to squat type exercises in the rehabilitation of ONE condition - ACL injury.

It appears that in the open chain exercise, especially including using isokinetic dynamometer, that knee extension is associated with a relative anterior translation of the tibia on the femur. However, doing closed chain exercises for knee extension (the squat) does not cause the anterior translation of the tibia. This translation in the open chain exercise applies a longitudinal strain to the ACL. Given the fact that these studies were geared toward developing a rehabilitation protocol for ACL injury one must logically assume that this strain on an already injuried tendon would be contraindicated.

Rather disturbing is the fact that the race to use "closed chain" rehabilitation methods for athletic injuries to tissues and joints other than the ACL and the knee are often supported in the literature (case reports) by the above mentioned phenomenon in the knee. Some proponents of closed chain exercise do, however, point to the importance of making rehabilitation exercises similar to the actual event.

This would of course mean that, for example, football punters should not do closed but do open chain exercise.

*** THIS IS THE MEDLINE SEARCH REFERRED TO ABOVE

Maitland ME, Lowe R, Stewart S et al. Does Cybex testing increase kneelaxity after anterior cruciate ligament reconstructions? Am J Sports Med 1993;21(5):690-5.

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