Biomechanics is the science of human motion. It is a science that helps us to understand the human body as a system of relationships and interactions that produce smooth efficient movement. It studies the effects of internal and external forces on the human body in both movement and rest. The challenge is to make this science that can be quite technical and complex practical and applied. I have found it helps to think of the big picture, think of whole movements not individual muscles. Visualize and actualize how the parts fit together. Movement should flow; there should be no herky-jerky movements. Look at the movement in the context of the end result. It is not necessary to be a biomechanist, but you can think biomechically to improve your effectiveness as a coach, trainer or therapist.
It is important to remember that biomechanics as a science does not stand-alone. There is a convergence of the sport sciences that leads to optimum performance. The coach should have a basic understanding of how all the sciences interact in a practical applied manner. For example mechanically correct technique will result in more efficient movements, which results in less energy cost to perform the movement.
I prefer to think of human motion and the subsequent performance as the interaction of three movement constants. Those constants are the body, ground and gravity. The body is central. It is an intricate system of levers and motors (muscles) that enable use to produce or reduce the necessary force to produce the desired movement in three planes of motion. Gravity is the second movement constant; it serves to load the system. It is always there; we live in a gravitationally enriched environment. Movement involves attempting to beat and cheat gravity because gravity is always trying to best us. The third constant is the ground. It is from the ground we actually derive force; we are terrestrial beings that must learn to use the ground effectively. We learn and adapt rapidly to varied surfaces. We must understand that we get out of the ground what we put into it. This is called ground reaction force. Typical ground reaction forces for athletic activities are: Walking 1.2 – 2.0 x body weight, Running 2.0 – 3.0 x body weight, Sprinting 7.5 x body weight, Long Jump Takeoff 10.9 x body weight, Lay-up Landing 8.9 x body weight, and cutting 3 x body weight. Typically these forces are imparted to the ground in very short periods of time. In World Class sprint performance the amount of time the sprinters foot is on the track can range from 0.08 to 0.10 second per foot contact. This represents Impulse, which is the amount of force that the athlete can put into the ground in the least amount of time.
In order to apply biomechanics it is imperative to understand the distinction between technique and style. For example a high leg kick in pitching is an example of individual style. At the moment of truth, which is the point of release every pitcher must do certain things to achieve results, regardless of how they look getting to that point. Do not copy the performers individual style. Look beyond individual personal style points and find the underlying principle that enables that movement to be effective. Coach that! Look for the keys that make them able to achieve their performances. Remember, everyone has a movement signature that is as individually unique as a fingerprint. Therefore it is important to carefully observe and study the athlete before making any significant changes in their technique. Make sure that what you see is what is detracting from their performance. There is no secret code that needs to be cracked to elicit peak performance, just some simple laws of motion that must be understood and applied.
