Collision Mechanics
Collisions occur with every movement we make, that is how we interact with the world. Whether it is our hands on the keyboard, the barbell coming to rest on our backs or the push-off from the blocks into a sprint. Collisions are a regular occurrence, and that is in fact how we propel ourselves through our environment. The interactions we have with the external world change the shape of our bodies, and that shape change is what permits our mobility.
A straightforward, and common example would be walking. The moment our foot strikes the ground, the tissues and joints that comprise our bodies reorient themselves to accommodate the force traveling through us. This change in position stores energy via the elastic mechanisms within us, and that storage eventually gets converted into forward propulsion. Let’s drill down on that for a sentence or two and use the ankle as the point of reference. The foot strikes the ground; the heel then moves into a position termed pronation via that same force. Pronation lengthens the tissues on the plantar aspect of the foot, and like a sling shot they then return that force into the Earth, moving us forward.
Another common example seen in the fitness realm is during a loaded squat. Once the barbell collides with our body, tension is almost immediately developed. That tension is then slowly released, like pulling back on that same sling shot from earlier. Once we hit our desired depth, we can utilize that stored energy to return to the starting position. An easy visual here could be the lower back, and specifically where the lumbar spine meets the thoracic. This is home to a dense region of connective tissue that, once loaded, develops tension and springs our body from the depth of the squat to the standing position. We need the interactions, the collisions, in order to shape our body in such a way that we can go where we want to go.
The mechanics involved with colliding are paramount to how we move. We actually need them to get around, without something to push against, we are motionless. Think about it this way, try to move a heavy dumbbell while you’re treading water in a deep pool. Even though you have buoyancy on your side, you have nothing but the water to push against and that medium isn’t helping much. Changing shape and manipulating energy is how we get where we want to be, and everybody is trying to go somewhere.
Austin Ulrich, Physical Therapist
