CLOSED KINETIC CHAIN EXERCISES

By: Bill Steinberger, MS, PT, CSCS

Most functional movements in the lower extremity take place when the foot is on the ground. The hip, knee and ankle joints, when taken together, comprise the lower extremity kinetic chain. When the distal segment is fixed and proximal segments move, the motion is called closed kinetic chain motion. Muscle contractions in closed kinetic chain motion are different from those in open kinetic chain motion at the same joint, and they also recruit all 3 joints in unison. Joint motion in the lower extremity is caused by many controlled muscle contractions that are the opposite of those in the open kinetic chain. For example, in the open kinetic chain, knee flexion is caused by concentric contraction of the hamstring muscles, which moves the tibia towards the femur. During closed kinetic chain motion, knee flexion is caused by controlled eccentric contraction of the quadriceps muscles, which moves the femur towards the tibia.

Closed kinetic chain exercise has become highly popular in rehabilitation, partly due to the belief that it is more closely related to function than open kinetic chain exercise. It is also believed that closed kinetic chain exercises are safer, particularly with regard to a healing anterior cruciate ligament (ACL) graft. Research has shown that ACL strain is reduced during closed kinetic chain exercise by virtue of the axial orientation of the applied load and muscular co-contraction of the quadriceps and hamstrings. In addition, closed kinetic chain exercise, through recruitment of all hip, knee and ankle extensors in synchrony takes advantage of specificity of training principles.

Research has also shown that closed kinetic chain exercise is more effective than joint isolation exercise in restoring function in patients with patellofemoral dysfunction, improving reflex stabilization and proprioception, reducing pain and promoting a return to normal daily activities and sports. For athletes in particular, closed kinetic chain exercise has been shown to more greatly improve strength and jumping ability in comparison to open kinetic chain exercise.

While open kinetic chain exercise certainly has its benefits and its own place in rehabilitation and strength training of the lower extremities, it is important to incorporate (and quite possibly emphasize) closed kinetic chain exercises for the greatest functional gains.