Instrument-assisted soft tissue mobilization increases myofascial trigger point pain threshold

A myofascial trigger point (MTrP) has been defined as a hyperirritable, palpable nodule in a skeletal muscle. The signs and symptoms of a MTrP include muscle pain, weakness, and dysfunction. MTrPs are common problems associated with soft tissue pathology. Having an intervention to decrease MTrP pain can be clinically valuable.

To determine if a series of six instrument-assisted soft tissue mobilization (IASTM) treatments rendered over three weeks would influence the pressure pain threshold (PPT) of a myofascial trigger point (MTrP).

Randomized, control trial of healthy individuals (n = 29) with MTrPs in the upper trapezius muscle. The intervention was six IASTM treatments rendered over three weeks. Each treatment included 1 min of sweeping with the GT-1/HG-2 (handle bar), 1 min of swivel with the knob of the GT-1/HG-2 directly over the MTrP, 2 min of fanning with the GT-4/HG-8 (convex single bevel), and concluded with 1 min of sweeping with GT-1/HG-2. The outcome measure used a dolorimeter to compare PPT before and after three weeks in both the treatment and control groups.

Paired t-test for PPT pre-test and post-test of the control and treatment groups were p = 0.42159 and p = 0.00003, respectively. A one-way ANOVA of the control and IASTM groups revealed a statistically significant difference (p < 0.0001). The power calculation was greater than 0.99.

A 5-min intervention using three IASTM techniques can effectively increase the PPT of a MTrP in six treatments over a three-week period of time.