Influence of pressure-pain and vibrotactille sensitivity by isometric relaxation in a location with myofascial trigger point

Objective: The aim of this study was to evaluate the effect of post-isometric relaxation (PIR) on pressure pain treshold and vibrotactile theshold in the area of myofascial trigger point. Methods: The change in pressure pain threshold and vibrotactile treshold was taken from the area above myofascial trigger point number one trapezius muscle - pars ascendens, and the vibration treshold at dorsum of metacarpal bone of the index finger. Fifty myofascial trigger points were examined (twenty-four from a group of probands with chronic cervicalgia or cervicobrachialgia syndrome, twenty-six in the control group). Results: The pressure pain threshold and vibrotactile threshold did not change after the PIR in the group of patients. But the threshold of vibration sense significantly decreased (nearly by 18%, p = 0.001). The result was opposite in the control group. Pressure pain threshold increased by 11% (p < 0.001) and vibrotactile threshold fell by almost 16% (p = 0.001). Vibration threshold did not change. Conclusions: The study confirmed that PIR can affect not only the pressure pain treshold, but also vibrotactile and even vibration treshold. PIR revealed an alteration to pain perception, vibrotactile and vibratin sensation in the group of patients. This alteration had not been obvious (visible) before..