Comparing the Reciprocal Inhibition Method and Post-isometric Inhibition Method of Muscle Energy Technique on the Spinal Reflex Excitability in Healthy Subjects

Overview

This a cross-over study to compare the effect of two different muscle energy techniques (MET) including post-isometric inhibition and reciprocal inhibition on the spinal reflex excitability. The study contains two experimental groups, while one group will receive post-isometric inhibition MET in the first stage and reciprocal inhibition MET in the second stage, the other group will receive reciprocal inhibition MET in the first stage and post-isometric inhibition MET in the second stage.

Reciprocal inhibition MET works based on the two mechanisms a) voluntary activation of agonist muscle that is simultaneously accompanied by the inhibition of the antagonist muscles or b) the activation of muscle spindle which causes a reflexive contraction in the agonist muscle (known as the stretch reflex) and relaxation of the antagonist muscles. By using this method, the activation of agonist muscles may inhibit or deactivate the antagonist muscles which may permit the therapist to introduce further ROM to the affected joint. The other method of MET is post-isometric relaxation which works based on the two mechanisms including; 1) activation of Golgi Tendon Organs (GTO) that located between the muscle belly and its tendon and 2) presetting muscle spindles by muscle contraction witch project information to the spinal cord via afferent type II fibers and through a complex central control systems, the spindle is preset to adjust the tone of the muscle. It seems that moderate isometric contraction of muscle may preset the muscle spindle and cause a post-isometric relaxation within the agonist muscles which now can be stretched further, and this may permit the therapist to introduce further ROM to the affected joint and help to improve joint mobilization.