Open versus closed kinetic chain Dr. Ali Abd El-Monsif Thabet

Open-Chain Exercises Open-chain exercises involve motions in which the distal segment (hand or foot) is free to move in space, without necessarily causing simultaneous motions at adjacent joints.

Closed-Chain Exercises Closed-chain exercises involve motions in which the body moves on a distal segment that is fixed or stabilized on a support surface.

Advantages and disadvantaged of open versus closed kinetic chain Open- and closed-kinetic-chain exercises offer advantages and disadvantages in the rehabilitation process. The choice to use one. or the other depends on the desired treatment goal.

Carryover to Function and Injury Prevention There is evidence to demonstrate that both open- and closed-chain exercises effectively improve muscle strength, power, and endurance. Exercises should be incorporated into a rehabilitation program that simulate the desired functions .

Carryover to Function and Injury Prevention The majority of activities performed in daily living, such as walking, climbing, and rising to a standing position, as well as in most sport activities, involve a closed-kinetic-chain system. With the exception of a kicking movement, there is no question that closed-kinetic-chain exercises are more sport- or activity-specific, involving exercise that more closely approximates the desired activity.

The Concurrent Shift in a Kinetic Chain The concept of the concurrent shift applies to Particular muscles that have distinctive muscle actions within the kinetic chain during weight-bearing activities. For example, the rectus femoris and hamstring in squat to stand exercises.

The effect of open versus closed kinetic chain exercises on knee joint Two critical forces at the knee joint A shear force occurs in a posterior direction that would cause the tibia to translate anteriorly if not checked by soft tissue constraints (primarily the anterior cruciate ligament). The second force is a compressive force directed along a longitudinal axis of the tibia. Weight-bearing exercises increase joint compression, which enhances joint stability.

The effect of open versus closed kinetic chain exercises on knee joint In an open-kinetic-chain seated knee joint exercise, as a resistive force is applied to the distal tibia, the shear and compressive forces would be maximized When a resistive force is applied more proximally. shear force is significantly reduced, as is the compressive force. If the resistive force is applied in a more axial direction, the shear force is also smaller . If a hamstring co-contraction occurs, the shear force is minimized.

The effect of open versus closed kinetic chain exercises on knee joint Closed-kinetic-chain exercises induce hamstring contraction by creating a flexion moment at both the hip and the knee, with the contracting hamstrings stabilizing hip and the quadriceps stabilizing the knee. Co-contraction of the hamstring muscles helps to counteract the tendency of the quadriceps to cause anterior tibial translation. efficient in reducing shear force

OPEN-VERSUS CLOSED-KINETIC-CHAIN ACTIVITIES IN THE UPPER EXTREMITY the upper extremity is most functional as an open-kinetic-chain system. Most sport activity involve movement of the upper extremity in which hand moves freely. These activities are generally dynamic movements, often occurring at high velocity such as throwing a baseball, serving a tennis ball spiking a volleyball. In these movements, the proximal segments of the kinetic chain are used for stabilization while the distal segments have a high degree of mobility.

Figure 8 Leg-press exercise.

Figure 7 Stairmaster stepping machine

Figure 9 Terminal knee extensions using surgical tubing resistance.

Figure 10 Stationary bicycle

Figure11 Balance board exercise.

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