Kinetic Chain Exercises
Whether you are training for performance and health or rehabilitating an injury, you have most likely encountered both open and closed chain exercises. The differences between the two are important to understand, as exercise prescription will dictate safety, functionality and forward progress.
Before diving into the literature, a few terms need to be defined. Open kinetic chain exercises involve movements where the load is placed on the distal (i.e. hands or feet) part of a limb. The limbs are able to travel through a greater range of motion and typically a single muscle group or joint is isolated. Simply put, the force that we apply causes the weight to move while the rest of our body stays fixed. Common examples of open chain exercise include knee extensions and bicep curls. On the other hand, closed kinetic chain exercises occur when the distal segment is fixed. Typically, the weight is loaded through the individual’s center of mass and the force is applied to a stationary object. The object (ex. ground during a squat, bar during a pull-up) does not move, but the force that we apply to it causes our body to change position. Each body part transfers force to its adjacent segments as these movements’ tend to incorporate multiple joints and muscle groups.
With the overhead athlete (ex. baseball, volleyball and water polo), there is a necessity for open chain exercises as these individuals need to gain adequate mobility, motor control and strength in order to allow for optimal performance and injury prevention. One should proceed with caution and monitor the volume of these movements as they cause an increased force through distraction, rotation, or shear as well as an increase in joint deformation. Ultimately, open chain exercises mimic the functionality of the upper limbs but the factors mentioned above should be considered, especially in an acute rehab setting. Closed chain exercises are more functional. An exception would include those athletes who compete in kicking sports; both open and closed chain exercises are preferred in this instance. Generally, closed chain exercises are deemed to be safer. Since the weight is loaded through an individual during these movements, increased joint compression is seen which improves joint congruency and dynamic stability. As well, sequential co-contraction of muscles throughout the body serves to further stabilize joints. One of the most important characteristics seen in closed chain exercises is proper joint centration. Functional joint centration allows for the best possible distribution of loads where the joints articulate. Said differently, the optimal position for a joint to support the body is seen when there is balance of muscle tension acting to support a centered joint. Due to this fact, most rehabilitation protocols (both lower and upper body) should start with closed chain exercises in order to encourage greater recruitment and better joint positioning. These movements involve the neuromuscular and motor control systems (i.e. the ‘software’ that controls your body) to a greater extent, which promotes coordination and proprioceptive feedback to initiate muscular control. Closed chain exercises also prove to create minimal distraction, rotational, and shear forces, which exerts less stress towards healing structures. The only con involving these types of exercises would be the appropriateness in relation to functionality of the upper limbs.
There are situations where both open and closed kinetic chain exercises are suitable; it all depends on the type of injury, goals of the individual and the specifics of the case. Above all, it is important to have a justified reason for your exercise choice, both in rehab and performance. These decisions should be well thought out and should consider functionality, level of ability and most importantly, safety and injury prevention.