Related Terms

• Bench press, closed kinetic chain exercises, CKCE, kinetic chain, knee extensions, open kinetic chain exercises, OKCE, squat.

Background

• Kinetic chain exercise is a specific type of physical exercise that may be integrated into aerobics, circuit training, certain endurance training, weight lifting, pilates, yoga or kickboxing. It may also be used in physical therapy, such as knee rehabilitation.

• A kinetic chain is a chain of joints exercised together. For example the hip, knee, and ankle joints, when taken together, comprise the lower extremity kinetic chain.

• Whether used for rehabilitation purposes or for strengthening purposes, there are two types of kinetic chain exercises: open (OKC) and closed (CKC). Closed kinetic chain exercises (such as squatting) involve weight bearing while open kinetic chain exercises (such as active flexion-extension) of the leg do not.

• 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. In contrast, open kinetic chain exercises use isolated joint and muscle function and the motion is uni-planer.

• Closed kinetic chain exercise has become popular in the last five to ten years for use 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. Clinicians also contend that CKC exercise is equally effective as OKC exercise in restoring quadriceps femoris muscle force production following ACL reconstructive surgery.

Technique

• Kinetic chain exercises are usually performed in three sessions per week. They may be done at home or at a gym, individually or under the supervision of a physical trainer or physical therapist. They may also be incorporated into various exercise programs.

• Whether used for rehabilitation purposes or for strengthening purposes, there are two types of kinetic chain exercises: open and closed. Closed kinetic chain exercises (such as squatting) involve weight bearing while open kinetic chain exercises (such as active flexion-extension) do not.

• 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 quadricep contraction, which will strengthen the quadriceps and restore quadricep power output.

• 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, and lunge.

Theory/Evidence

• During kinetic exercises there are typically two kinds of external forces: shear and compression. Using the knee as an example, shear force causes a side-to-side shift in the knee, which is typical of the open chain exercises, and may place a large amount of stress on certain ligaments (such as the ACL). Compression force is caused from a strong external force placed on the knee, which pushes the head of the femur together with the head of the tibia. Pincivero et al. found that closed chain kinetic exercise (CKCE) reduced shear force and increased compression force in the knee joint. CKCE activated the hamstrings, which increase knee stability. Similarly, Escamilla et al. found that there was a large amount of quadricep activity during both exercises. They found strain placed on the ACL during exercise is directly related to the shear force placed on the knee joint. When shear force is decreased, this leads to a decrease in displacement. During CKCE the hamstrings are contracted, which reduces displacement.

• Previous research performed comparing OKCE and CKCE found that CKCE was a safer and more beneficial from of exercise for rehabilitation or strengthening. However, according to a recent study, throughout the entire flexion (bending of a joint) range, the open kinetic chain stresses are not supraphysiologic (beyond normal physiologic range) nor significantly higher than the CKCE stresses. These findings conflict with previous research, which state that open kinetic exercises are riskier. However, OKCE may be important alternatives for patients who have undergone an operation and may feel too unstable on their feet to do closed CKCE. OKCE at low flexion angles may be recommended for patients whose knee injuries prevent deep knee joint flexion.

• Moreover, based on a review of data, it does not appear that clinicians should completely abandon more traditional OKCE and replace them with CKCE in all rehabilitation or strengthening cases. Both types of exercise may be modified to minimize the risk of applying excessive strain on injured ligaments and joints. Depending on the functional goals of the individual, both OKCE and CKCE may be appropriate.

Safety

• A qualified healthcare provider should be consulted before beginning any new exercise program.

• To avoid soreness and injury, individuals contemplating an increase in physical activity should start out slowly and gradually build up to the desired amount. People with chronic health problems such as heart disease, diabetes, or obesity, or those high at risk for developing these problems, should first consult a physician before beginning a new program of physical activity.

• Squatting may be linked with an increased risk of knee and/or low-back injury and pain.

Author Information

• This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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2. Cohen ZA, Roglic H, Grelsamer RP, et al. Patellofemoral stresses during open and closed kinetic chain exercises. An analysis using computer simulation. Am J Sports Med. 2001 Jul-Aug;29(4):480-7. View Abstract

3. Escamilla RF, Fleisig GS, Zheng N, et al. Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Med Sci Sports Exerc. 1998 Apr;30(4):556-69. View Abstract

4. Escamilla RF. Knee biomechanics of the dynamic squat exercise. Med Sci Sports Exerc. 2001 Jan;33(1):127-41. View Abstract

5. Fitzgerald GK. Open versus closed kinetic chain exercise: issues in rehabilitation after anterior cruciate ligament reconstructive surgery. Phys Ther. 1997 Dec;77(12):1747-54. View Abstract

6. Heller BM, Pincivero DM. The effects of ACL injury on lower extremity activation during closed kinetic chain exercise. J Sports Med Phys Fitness. 2003 Jun;43(2):180-8. View Abstract

7. Pincivero DM, Lephart SM, Karunakara RG. Relation between open and closed kinematic chain assessment of knee strength and functional performance. Clin J Sport Med. 1997 Jan;7(1):11-6. View Abstract

8. Pincivero DM, Aldworth C, Dickerson T, et al. Quadriceps-hamstring EMG activity during functional, closed kinetic chain exercise to fatigue. Eur J Appl Physiol. 2000 Apr;81(6):504-9. View Abstract

9. Rogol IM, Ernst G, Perrin DH. Open and Closed Kinetic Chain Exercises Improve Shoulder Joint Reposition Sense Equally in Healthy Subjects. J Athl Train. 1998 Oct;33(4):315-318. View Abstract

10. Stensdotter AK, Hodges PW, Mellor R, et al. Quadriceps activation in closed and in open kinetic chain exercise. Med Sci Sports Exerc. 2003 Dec;35(12):2043-7. View Abstract