Reciprocal Inhibition—“when a movement needs to be performed, a signal from the central nervous system (CNS) to activate a muscle on one side of a joint causes the inhibition of CNS signals to its functional antagonist, causing it to relax and lengthen to allow the desired movement to occur. If a muscle is chronically overactive and receiving elevated contraction signals in its resting position, then reciprocal inhibition dictates that its functional antagonist will have its neural drive chronically inhibited, in turn. When that inhibited muscle needs to be an agonist for a movement, the chronic inhibition prevents it from correctly doing its job, reducing the amount of force it can produce. Muscles in this situation are referred to as underactive/lengthened.” (NASM, 2008).