Kinetic Chain Exercises Open vs. Closed Kinetic Chain Mazyad Alotaibi

Definition: In rehabilitation settings such as sports and physical therapy clinics, the body is often viewed as functioning in interconnected segments, for example, the arm, shoulder, and the spine. The theory behind this is that movement of one part affects the others via a chain reaction. Kinetic chain were used to describe how forces occur during human motion and how segments (structures) of the body are linked together.

Types: there are two types of kinetic chain exercises: Open (OKC) and Closed (CKC). Closed Kinetic Chain Exercise (CKC): (such as squatting) involve weight bearing Distal segment is fixed or stabilized relative to proximal segment Used more often in rehabilitation for lower extremity conditions In closed kinetic chain exercises, movement at one joint produces predictable movements at all other joints. Weight bearing closed kinetic chain activities may increase joint compressive force and thus enhance joint stability. Open Kinetic Chain Exercise (OKC): (such as active flexion-extension) of the leg do not involve weight bearing . Distal segment is mobile and not fixed In contrast, open kinetic chain exercises use isolated joint and muscle function and the motion is uni-planer.

Closed kinetic chain exercises (CKCE): These are physical exercises performed where the hand (for arm exercises) or foot (for leg exercises) is fixed and cannot move. The hand/foot remains in constant contact with the surface, usually the ground or the base of a machine. These exercises are typically weight-bearing exercises, where an exerciser uses their own body weight and/ or external weight. Arm CKCE include pushups and handstand pushups. Leg CKCE include back squat, front squat, leg press. Closed kinetic chain exercise could be used after anterior cruciate ligament (ACL) reconstructive surgery. Closed kinetic chain exercises appear to have gained popularity over more traditionally used open kinetic chain exercises because many clinicians believe that CKC exercises are safer and more functional.

Technique: Open kinetic chain exercises (OKCE): These exercises are performed typically where the hand or foot is free to move. These exercises are typically non-weight bearing, with the movement occurring at the elbow or knee joint. If there is any weight applied it is to the distal (away from the point of attachment or origin) portion of the limb. Arm OKCE include the bench press and leg OKCE include knee extensions and straight leg raises. OKCE for legs concentrate on a strong quadriceps contraction, which will strengthen the quadriceps and restore quadriceps power output.

Muscle Action in the Kinetic Chain Muscle actions that occur during open kinetic chain activities are often reversed during closed chain drills Open chain – muscle origin is fixed with insertion moving Closed chain – muscle insertion segment is fixed and muscle work to move origin

Advantages of Open vs. CKC Exercises Closed Chain Exercises Increase joint compressive forces Increase joint stability Decrease shear forces Decrease acceleration forces Stimulation of proprioceptors Enhanced dynamic stability More safer and produce less threatening forces Co-activation and co-contraction Functional and very sports specific

Open Kinetic Chain Exercises OKC activities are used primarily to develop muscular strength Increased acceleration forces Decreased resistance forces Increased distraction and rotational forces Increased deformation of joint and muscle mechanoreceptors Promotes functional activity Often isolated to single joint motion

Using CKC Exercises to Regain Neuromuscular Control Functional weight-bearing activity requires coordinated muscle and joint function Lack of normal motion due to injury disrupts movement on multiple levels Closed chain activities requires integrated action of all segments – facilitates proprioception and joint position sense

Closed Kinetic Chain Exercises for the Lower Extremity Better understanding of kinesiology and biomechanics has allowed for increased and earlier use in rehabilitation Alteration in rehabilitation techniques and shift in protocols Number of lower extremity exercises available

Leg Press Decreases strain on low back, provides stability and takes advantage of kinetic chain Allows for Training more or less than body weight Training legs independently

Stair Climbing Useful for cardiovascular fitness and as OKC unit Functions, biomechanicaly, similar to leg press Maintain erect body position to maximize hamstring recruitment Elicits increased quadriceps EMG compared to hamstrings

Step-Ups Can be performed forward, backward and laterally Encourages movement of full body weight Stair climber maintains CoG at constant height Use caution when anterior shear forces are a concern Lateral step-up results in high levels of shear Hamstring activity not significant enough to neutralize forces Ideal for quadriceps strengthening

Stationary Bicycling Amount of weight bearing force exerted can be adapted based on athlete’s limitations Seat height must be adjusted to minimize knee flexion moment Seat can also be adjusted for ROM activities

Biomechanics of Open vs. CKC Activities in the Upper Extremity CKC exercise should also be incorporated into upper extremity rehabilitation Upper extremity generally operates as an open kinetic chain High velocity, dynamic movements Proximal segments serve stabilization role while distal segments exhibit high degree of mobility CKC activities for Upper limb include Push-ups, chin-ups, handstands

Combination activities Swimming and cross country skiing CKC generally used in upper extremity to strength and develop neuromuscular control in stabilizing musculature Allows them to function as a stable base more effectively during dynamic movements of distal segments

Shoulder Complex Joint CKC exercises can promote and enhance joint stability Enhances force couples Function of scapula stabilizers

Elbow Elbow is highly involved in open kinetic chain activities Propels objects at rapid velocities with accuracy When hitting, it must possess static stability and dynamic strength Swimming require it to produce power, and stability Gymnastics and wrestling rely on it as both an open and closed kinetic link for both stability and propulsion

CKC Exercises for the Upper Extremity Used to train co-contractions in the shoulder early in the rehabilitation phase Enhance stability and decrease shutdown of rotator cuff secondary to pain Can be utilized in later stages for endurance of glenohumeral and scapulothoracic musculature OKC exercises should also be incorporated particularly during middle phase of shoulder rehabilitation

For the elbow, CKC exercises assist in enhanced muscular balance and neuromuscular control of surrounding musculature Improve dynamic stability of proximal muscles OKC exercises are essential for regaining strength necessary for high velocity dynamic movements Throwing activities

Weight Shifting Variety of exercises available that facilitate dynamic stability through axial compression Can be performed in a series of positions on varying surfaces Degrees of body weight can also be altered

Shifting can occur in multiple directions Alterations in base of support PNF patterns can be incorporated Rhythmic stabilization