Open vs. closed chain kinetic exercises: A clinical application

The purpose of this paper is to define open and closed kinetic systems and their applications. Closed kinetic chain (CKC) exercises involve functional movement patterns in a weight-bearing environment with contraction of both the agonist and antagonist muscle groups. Open kinetic chain (OKC) exercise is a non-weight-bearing activity and involves a single muscle within a single plane of motion and is effective when isolation of muscle and joint activity is warranted. The arthrokinematics between these two types of exercises are different: OKC activities create greater shear forces within the joint with less joint compression, and CKC exercises have the reverse effect. This accounts for the current trend toward using CKC protocols in anterior cruciate ligament reconstruction rehabilitation. Understanding the impact of the concurrent shift on joint arthrokinematics will help the physician establish the appropriate progression of exercises when developing a rehabilitation program.