Question

What are the interactions/connections between joint angles in open kinetic chain verse closed kinetic chain?  Explain this relationship using knee flexion in both an open and closed chain example.

Answer 1

For an open kinematic chain, the joint angle can be changed without risking any adjustments to the other joints. Whereas in the closed kinematic chain, both ends of the chain are fixed and any adjustment of the angle in one joint results in the alteration of the angles in the other joint.

Kinematic chains are used to characterize the relationship between body and joint segments during movement.

Open kinetic chain exercises are usually characterized by a rotary stress pattern on the joint.

For example, when a seated knee extension is performed, the primary stress on the joint is the rotation of the distal tibia on the proximal femur, even if certain accessory movements such as rolling and translating occur.

Movement in one part of the closed chain causes movement in all other joints in a predictable manner.

For example, during a squat, movement at the knee joint is followed by movement at the hip and ankle joints.