A Principle or Truth of human movement is that the body is an integration of many systems – neurological, cardiovascular, and musculoskeletal (to name a few). Each system is made up of many integrated parts that can’t be separated or isolated. The musculoskeletal system is comprised of muscles and bones, but also tendons, ligaments, and other soft tissues that connect the different bone segments to create joints. Whenever our rehab or training programs focus on one muscle or a single joint, while attempting to exclude or limit the contributions from other parts of the body, the exercises in those programs become less like function. There may be reasons for a local isolation focus, but this should occur as part of the overall Strategy of integration.
Many years ago Dr. Gary Gray coined the term “integrated isolation.” As equipment was developed to isolate a particular joint motion or muscle for testing or rehabilitation, Gary saw the folly of this approach. While acknowledging the need to isolate at times, he advocated for a more functional approach. With his Strategy, the part was “isolated” while integrated with the rest of the body: Integrated Isolation. The Principle creates a Strategy to always maximize the integration. Pure isolation is not functional, while integrated isolation is functional.
The authenticity of integration is critical not only to rehabilitation but also performance training. Integrated training and rehabilitation programs allow the body to “measure” the physical forces of gravity, ground reaction force, mass, and momentum. The body can learn to withstand, accommodate to, and take advantage of these forces in the environment. The mechanoreceptors in the body provide coordinating information (proprioception) with integrated movements. Isolated joint exercises limit the proprioceptive information and deny the body the information required to create efficient muscle synergies.
Integrated muscle function is characterized by loading transformed into exploding. Muscle actions are never in a single plane. Muscle function is tri-planar due to two “truths”: (1) joint motion occurs in three planes; and (2) muscle alignment from origin to insertion is never straight. During integrated global body movements, muscles will influence multiple joints in three planes of motion. This multiple joint influence is true even for muscles that anatomically cross only one joint.
For example, the gluteus maximus crosses the hip joint, so its influence at that joint is not questioned. But because of the attachment to the femur, it will influence the knee. During the landing phase of running the gluteus maximus slows down knee flexion and then helps with knee extension. This could be called “adjacent joint” action. At the time of knee flexion, the forward motion of the lower leg creates ankle dorsiflexion. By controlling knee flexion the gluteus maximus contributes to decelerating ankle dorsiflexion. Let’s consider this “non-adjacent” joint action. Try training the gluteus maximus to assist in the control of ankle motion with your patient / client on a table!
More than 30 years ago, Dr. Gary Gray wrote an article entitled “The Achilles Hip.” Based on the Principle of Integration, he proposed that the cause of, and the solution to, Achilles tendinitis were the hip muscles. Programs to resolve Achilles tendon pathology require Strategies that emanate from the appreciation of the Principle of Integration. This is true throughout the body. Without integration the perception of movement is inhibited, the body’s recognition of what needs to occur is compromised, and the muscle activation patterns become ineffective and inefficient resulting in less than optimal training and rehabilitation.