A search term on my blog recently was “what does eccentricity control?” Well, it can control having a somewhat strange personality, which I do, so I guess eccentricity controls my personality.
But, when talking about muscle movement and what is controlled in that way, think of downward movements.
Eccentric muscle contraction occurs when the muscle is being used but it’s lengthening. Think of a bicep curl, everyone knows what that is, the hand is being brought closer to the upper arm as a result of contracting the biceps muscle. The muscle is getting shorter. This is called a concentric contraction and is more commonly, I think, of how people think a muscle works.
Now think of putting down a cup of water on the table from a standing position. That same muscle is controlling that movement, the biceps, but it is lengthening. Your forearm is moving further away from the upper arm. Your biceps are in control of moving your lower arm downward to the table. The muscle is getting longer.
Now, think of walking downhill. The quadriceps are mainly in control here. When you take a step on a descending slope, the quads are active, being lengthened to control that movement. Walk down a hill or down a step and put your hand on the front of your thigh, you’ll feel your quadriceps being activated. The attachment of the quads on the lower leg is moving further away from the attachment of the quadriceps muscles which is at the top of the thigh and hip.
The opposite occurs when going uphill, The quads are again in play here but thigh is getting closer to the lower leg. The muscles are shortening. The attachment of the quads on the lower leg is moving closer to the attachment of the quadriceps muscles at the top of the thigh/hip.
Eccentric contractions are so important and are harder. They’re usually the last to come back after an injury but I’ve seen patients that are able to control a muscle eccentrically first, so we went with that.
eBooks are coming…so all of the information on this blog will be in one place.