From: Paul Chek Date: Mon, 16 Jun 1997 06:35:16 -0600 (MDT) Subject: (Weights-2) Open vs Closed chain exercise Regarding Richard Muller's question: >What do "open kinetic chain" and "closed kinetic chain" mean?< The terms "Open and Closed Kinetic Chain" were developed by Dr. Steindler and my recollection of the first published item referring to the terms is "Text Book Of Kinesiology", published in 1956. Because I am currently in Australia lecturing and running internships I don't have access to my library and can't give you the publisher although it is long out of print. To simplify the terms, OPEN KINETIC CHAIN exercises are those exercises in which the force applied by the body is great enough to overcome the resistance. An example of an open chain exercise would be a bench press, or any leg press which allows the force applied to move the load away from the body. In contrast, CLOSED KINETIC CHAIN EXERCISES are those in which the force applied is not great enough to overcome the resistance. Examples would be the push-up and squat exercises. To clarify for the novice list reader, even though the load applied during the squat is on the body, the force generated is applied to the ground, not the bar. To move the bar, the lifter must apply a force against the earth great enough to overcome the resistance created by the load on the bar. How this information is relevant to Richard Muller's questions regarding knee extensions as a means of improving squat strength: The knee extension is performed such that the thigh is fixed to the machine, while the knee extension force generated by the quadriceps serves to move the tibia across the femur. In a squat, the trunk, hip and knee extensors act as prime movers, moving the femur across the tibia, which is the fixed distal segment (along with the foot) in this closed kinetic chain exercise. The relevance here lies in the fact that the motor recruitment patternsfor the knee extension are 180 degrees out of phase with the recruitment patterns activated by the CNS to perform the squat. Another classic exampleis the difference between performing a lat pull down and a chin-up. Any serious climber will tell you that there is a huge difference in the strength quality necessary to perform a closed chain pull-to-press over a rock ledge and an open chain lat pull down." It is this very point which must be considered when designing resistance training programs for athletes. If for example you use an open chain leg press in attempt to develop explosive strength for sprinting, you will NEVER achieve optimal performance. To shed further light on this potentially "very deep subject", when training a cyclist, you have carryover from both open chain and closed chain exercises due to the very nature of cycling (pushing the pedal down from a seated position vs. standing and driving a big gear or during an intense hill climb). I choose this example because this is where Open and Closed Chain have a grey area: Initially, when the cyclist stands up to drive downward on the pedal, his body may momentarily move away from the pedal, until the arms counter the upward movement of the body - turning the movement into an open chain movement as the pedal descends away from the body. The same scenario can be developed for a boxer punching an opponent in the head; the chain is closed upon contact, yet opens as the force of the arm overcomes the momentary resistance created by the head (a concept I am very familiar with by the way!). This is why boxers can be seen doing both open and closed chain exercises in their training programs, if their coach knows what he is doing! In bodybuilding, the concept of open and closed chain is far less relevant because there is no athletic component to bodybuilding; the goal being to have the biggest muscles, the best proportions and a good posing routine. Bodybuilders can benefit greatly from this information though, as alternating between open and closed chain exercises serves to more fully develop both the nervous system and musculature due to the variety of recruitment patterns needed. To give another illustration that may help clear the confusion, consider that running is a closed chain dominant exercise (you apply force against the earth and you move), while cycling is predominantly an open chain exercise (press on the pedal and it moves away from you). If there was any real transfer of strength qualities and skills developed, Carl Lewis would make a hell of a track cyclist and the Race Across America would probably be won by an ultra distance runner, or vice versa. There are many other factors I could go into but it is dinner time! This information should be standard to all who prescribe exercises. The reasons above should make it obvious why!! Sincerely, Paul Chek MSS, HHP, NMT PAUL CHEK SEMINARS US - 1-800-552-8789 New Zealand and Australia 64-9-478-2111 www.paulchekseminars.com