Force
Force is very straight forward, such that Isaac Newton developed an equation which many have probably seen before: Force = mass x acceleration, or, F=ma. This equation is so powerful that it was one of the essential pieces of physics that contributed to the moon landing. Generating force is what propels us around in the world, and despite our fascination with strength, the more precise measurement is that of force absorption and production.
The fitness and rehab worlds seem to be endlessly searching for more strength. As a previous powerlifter, I can understand. The thing about the term, strength, is that it is a fairly nebulous word that ultimately comes down to force production. It may sound like semantics, but the words we use to describe our roles in people’s health and movement are important. If we want to improve upon their force production, then we should consider the equation above. Which variables do we need to alter in order to help clients move the way they want to?
There are two primary influences in how we can move in our environment. We can absorb force, and slow down, or we can produce force and speed up. In all circumstances, these two aspects of movement are occurring somewhere. Our intentions dictate which element we want to bias. Without sufficient braking capabilities we fall, however if we brake too hard we find ourselves in the same predicament. The fine-tuned ability to slow down, absorb forces, and then redirect them back to the environment is what smooth, fluid movement looks like. As an example, if we want to squat well, we first may begin to slow down absorb forces from the ground and/or the weight we’re holding. Once we reach the bottom of our squat then we redirect those forces and push into the ground returning to the standing position. This is applicable to each and every movement we create. By increasing our mass via the resistance of the exercise the amount of force within the activity immediately increases and we must find a way to manage it.
Force is defined relatively simply, we take our mass and multiply it by our acceleration. Strength is a term we use in reference to force, but it muddies the waters. Should we elect to alter our movement capabilities, we should stop and think about what characteristics we want to influence. If it revolves around force (and it probably does), then which aspect of the equation would provide us with the most direct route to our goal? Managing forces is not easy, but nature made it simple: either absorb them or produce them.
Austin Ulrich, Physical Therapist
