This study investigated the effect of integrated neuromuscular inhibition technique (INIT) in the management of piriformis syndrome. The outcome of this study indicated that INIT is effective in the management of a patient with PS. Even though there is evidence to suggest the effect of INIT in the management of non-specific neck pain, literature for the effect of INIT in the management of PS is lacking. This study is the first to report the effect of INIT in the management of PS.
INIT was developed by Chaitow et al. (
8) as an extension of techniques that are used to ameliorate somatic dysfunction. According to Chaitow et al. (
8), INIT involves the combination of two manual therapy techniques (muscle energy technique - MET) and positional release technique - PRT) which must be delivered in a single coordinated manner to achieve the most effective approach to treating trigger points (TrPs) and tissue dysfunctions.
Positional release technique has been investigated as one of the most effective manual therapy techniques for the management of PS (
11,
12). This technique involves the identification of TrPs, followed by the application of ischemic compression to reproduce the nociceptive response (
16). The limb is then placed in such a way as to minimize the tension in the affected muscle and subsequently, the painful TrP is deactivated (
17). The possible underlying effect of TrP ischemic compression was documented by a study (
18) which indicated that pain and muscle spasm relief from ischemic compression may be due to the reactive hyperemia produced in the area of the lesion, or from the spinal reflex arc.
On the other hand, MET has also been indicated in the management of PS (
9,
10). The concept behind using MET is to achieve sufficient muscle relaxation and lengthening either by using post-isometric relation (PIR) or reciprocal inhibition (RI). Post-isometric relation refers to the immediate decrease in the tone of the agonist muscles following isometric contractions that happens due to the effects of stretch receptors (Golgi tendon organs) which react to excessive stretching of the muscles by counteracting longer muscle contractions. This is a natural self-defense mechanism and has a lengthening effect due to the immediate relaxation of the whole muscle under tension (
10).
On the other hand, RI refers to the inhibition of the antagonist muscles due to isometric contractions of the agonist muscles which happens due to stretch receptors within the muscle spindles which work to maintain steady muscle length by providing information on the nature of the contraction (
10). When stretched out, muscle spindles produce nerve impulses, which augment contractions and thus prevent excessive stretching (
10). Better relief in pain and/or spasm in the muscles housing TrPs is achieved when MET is applied while the muscle is in a stretched position (
10). It has been thought that all the effects of INIT due to the administration of MET and PRT have significantly assisted in the restoration of pathological changes of the piriformis muscle and also lessened compressive forces on the sciatic nerve.