PARAMAUS, N.J. -- You may not realize it, but many students were learning the kinetic chain long before they learned their fractions or state capitals. Remember the song, “the shin bone’s connected to the knee bone?” That favorite childhood song is actually a good way to think about the kinetic chain.
The idea of the kinetic chain was first described in the late 1800s when scientists discovered that in a system fixed at both ends with a series of overlapping segments connected by joints, an applied force was transferred to adjacent segments in a chain reaction. This concept was applied to the human body in the 1930s, with the bones acting as the segments linked by joints.
A good example of the body's kinetic chain at work is the throwing motion. "What many people don't realize is the arm is actually just the last stop in the kinetic chain," said Dr. David A. Wang, a sports medicine physician at Hospital for Special Surgery. "The legs and trunk start the chain by generating the majority of the force behind the throw, which is then transmitted up to the arm, and ultimately out to the ball."
Because all segments in the kinetic chain are connected, an injury to one part can affect the entire chain. "By then overcompensating, it places increased stress on areas that are not used to handling them, potentially leading to injury," said Dr. Wang. "With the throwing motion, if the legs and trunk do not produce the necessary force, the shoulder and arm must work harder to offset this, placing them at risk for injury."
The kinetic chain also plays a large role in the rehab setting because the opposite is true as well. "If you rehab one part of the chain, the benefits can be seen elsewhere," said Dr. Wang. An example of this is the rehab for patellofemoral pain syndrome of the knee. Addressing further up the chain by strengthening the thigh, hip, and core, or further down the chain by correcting any abnormalities in foot biomechanics can improve symptoms at the knee.
Dr. David A. Wang is a sports medicine physician at Hospital for Special Surgery specializing in the treatment of acute and overuse injuries. His main clinical and research interests are overuse injuries, concussions, viscosupplementation injections, and the pre-participation physical exam. As a former collegiate baseball player, he also has a special interest in the care of baseball players. He practices at both the HSS Outpatient Center in Paramus and the hospital’s main campus in New York.