Alexander, "Open Versus Closed Chain
Kinetic Exercises After Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Study," The American Journal of Sports Medicine, vol.
Typically, compound movements are closed chain
, which essentially means the hands or feet are in contact with either the ground or with a machine.
If the hand is free to move in space, it is an "open chain." If instead the hand is holding onto a stable object/surface, for example a banister when climbing the stairs, it is a "closed chain
An example of an open chain exercise would be the knee extension, whereas the lunge is closed chain
. Closed chain
exercises more closely mimic the demands of running.
maneuvers can be used to compensate for inadequacies at a weak link in the chain.
Since the model contained a closed chain
(both feet were attached to the ground, creating a closed chain
bounded by the legs, ground, and pelvis), only 9 of the 15 DOFs were independent--6 in the legs and 3 at the ball joint between the trunk and the pelvis.
There is little research concerning the timing of activation of VMO and VL during the combination of closed chain
activity and an unstable surface.