At Gray Institute®, the movement exercises that make up our training, rehabilitation, and injury prevention programs are determined by Strategies. The Strategies emanate from the truth of human movement that we observe every day. These truths are called Principles that make up the Principles-Strategies–Techniques (PST) Process. One of the core Principles states that “the body is a Chain Reaction®.” The spiritual song entitled “Dem Bones,” although mixing bones and joints, tells the story in a wonderful manner: “The thigh bone connected to the hip bone, the hip bone connected to the backbone, …” The soft tissues of the body, including muscles, tendons, capsules, and fascia, connect all the bones together creating a relationship between all the joints. The study of the motion of the bones is called osteokinematics. The “connectedness” of movement can be referred to as the kinematic Chain Reaction®.

Understanding the Chain Reaction® provides movement practitioners with new methods for dynamically assessing the function of joints and muscles. 3DMAPS® (3D Movement Analysis & Performance System), from Gray Institute®, is a powerful tool to determine the relative success of the body’s ability to move in each of the three planes of function. Once dysfunction is identified, the means of eliminating barriers to successful movement are exponentially increased if practitioners leverage the body’s Chain Reaction®. The Performance System in 3DMAPS® provides an organized path for creating movement success. Motion begets motion! (For more information on 3DMAPS®, please visit 

This all sounds good, but what about practical application? To see Chain Reaction® in action, just stand up and reach with your right hand up and around your left shoulder as far as you can (comfortably). Your right foot will pronate / evert and your arch will lower. Your left foot will supinate / invert and will roll to the outside. In between, the right shoulder went through flexion and horizontal adduction. The thoracic spine and lumbar spine experienced rotation to the left. The right hip joint went through the motion of external rotation, while the left hip joint went through internal rotation. The Chain Reaction® went from the hand to the foot. But, if you fix the hand and take a step, it will go from the foot to the hand.

The power of the Principle becomes clear with patients / clients who have plantar fasciitis. Individuals have difficulty explaining how they developed this problem, and they suffer for long periods because of the difficulty in finding a resolution of the symptoms. The biomechanical cause is often propelling off a foot that is “unlocked” at the mid-tarsal joint. Why doesn’t the foot “lock up” during propulsion? How can we get the foot to “lock up”? Two questions with the same Chain Reaction® answers. The foot does not “lock up” because there is excessive pronation during landing, or insufficient supination during propulsion. Causes of excessive pronation include inefficient / weak calf muscles, posterior tibialis muscles, posterior lateral hip muscles, and abdominals. Reasons for failure to supinate include all the muscles listed above as well as poor trunk rotation and insufficient push-off of the opposite leg. As movement specialists, we can be confused by all the potential causes. Or we can be empowered by all the possible solutions. The road from “confused” to “empowered” is the path of knowledge about the biomechanics of the miraculous Chain Reaction® that is the human body. At Gray Institute®, we hope to be your guide for understanding the Applied Functional Science® truth of how the body works.

This knowledge enhances success. And, as you know, success then begets success – from a movement standpoint and an educational standpoint!