From
http://www.cmcrossroads.com/bradapp/docs/rec/stretching/stretching_2.html
Stretching and Flexibility - Physiology of Stretching
by Brad Appleton
When an agonist contracts, in order to cause the desired motion, it usually forces the antagonists to relax (see section Cooperating Muscle Groups). This phenomenon is called reciprocal inhibition because the antagonists are inhibited from contracting. This is sometimes called reciprocal innervation but that term is really a misnomer since it is the agonists which inhibit (relax) the antagonists. The antagonists do not actually innervate (cause the contraction of) the agonists.
Such inhibition of the antagonistic muscles is not necessarily required. In fact, co-contraction can occur. When you perform a sit-up, one would normally assume that the stomach muscles inhibit the contraction of the muscles in the lumbar, or lower, region of the back. In this particular instance however, the back muscles (spinal erectors) also contract. This is one reason why sit-ups are good for strengthening the back as well as the stomach.
When stretching, it is easier to stretch a muscle that is relaxed than to stretch a muscle that is contracting. By taking advantage of the situations when reciprocal inhibition does occur, you can get a more effective stretch by inducing the antagonists to relax during the stretch due to the contraction of the agonists. You also want to relax any muscles used as synergists by the muscle you are trying to stretch. For example, when you stretch your calf, you want to contract the shin muscles (the antagonists of the calf) by flexing your foot. However, the hamstrings use the calf as a synergist so you want to also relax the hamstrings by contracting the quadricep (i.e., keeping your leg straight).
It still does not answer the question as to how the agonists inhibit (relax) the antagonists.
Until that is understood I don't see how we are going to figure out how to stop spasticity. Researchers anyone? Whats your theory?
Dean what's your degree in? Did you learn all this stuff post stoke?
ReplyDeleteMy degree was in Accounting although my work is in computer programming. Which always has a cause and effect, its distressing that the medical world does not seem to have the same desire to find the cause of recovery or prevention. I learned everything post-stroke because no one else seems to know or want to know everything about stroke.
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