Exercises can be broken down into two main categories, open kinetic chain and closed kinetic chain. But what does this actually mean for the athlete who is training. Before we go any further let’s look at the word “Chain”. A chain is simply an amount of links joined to together and held in place by either a weld or by the strength of the structure itself; and herein lays the clue to the name. From a physiological point of view The “chain” that these terms refer to is the kinetic chain of the body, which simply means that all of your bones and muscles are connected in a “chain” and therefore the movements you make are also part of a that kinetic chain.
Open Chain Exercises
Putting simply, your hand or foot is free to move during an open chain exercise. These types of movements tend to isolate a single muscle group and a single joint. For example, the one joint involved during a bicep curl is the elbow and the muscle group it isolates is the biceps. The weight is placed at the distal (far away) portion of the limb. Examples of open chain exercises include chest presses, biceps curls, leg curls, and leg extensions.
Closed Chain Exercises:
During these movements, your hands or feet are in a constant, fixed position (usually on the ground) during the exercise (such as press up). Closed chain exercises work multiple joints and multiple muscle groups at once. For example, a squat involves the knee, hip and ankle joints, and multiple muscles groups (quads, hamstrings, hip flexors, calves and glutes).
When external weight is added, it is usually rested across the back of the shoulders or the front of the chest, which is considered much safer than the “distal” placement of weight during open chain exercises. Examples of closed chain exercises include press up, pull-ups, squats, and lunges, all of which can be done with or without added weight.
When I prescribe an exercise programme for a client I give them more closed chain exercises than open chain (apart from the bench press and rowing movements); as I believe they are safer and offer a greater metabolic challenge. They are also great athletes, too, since sports require multiple joint and muscle movements to happen at once. Very few movements in real life or in athletics isolate joints and muscles like open chain exercises do.
Closed chain exercises are safer for your joints; especially the knee joint, which is very vulnerable to stress and injury. The force involved in closed chain exercises like lunges and squats is compressive, meaning it actually stabilizes the joint and helps strengthen it. In contrast, open chain exercises, like knee extensions or hamstring curls produce shear force, which stresses the knee joint (and the ACL) and is more likely to result in injury.
Lutz GE etal (1993) “Comparison of tibiofemoral joint forces during open-kinetic-chain and closed-kinetic-chain exercises” The Journal of Bone and Joint Surgery. American Volume
W. Ben Kibler (2000) “Closed Kinetic Chain Rehabilitation for Sports Injuries” Am J Phys Med Rehabil. Volume 11, Issue 2, Pages 369–384