Comparison of the clinical and morphological effects of release techniques using manual pressure or an algometer on the latent trigger points of the trapezius muscle.

BACKGROUND AND PURPOSE: Using an algometer, therapists can objectively measure the pressure exerted on the body tissue. However, it is unknown whether administering accurate pressure by an algometer is more successful than the usual method of pressure release by hand in producing therapeutic effects. This study examined the effects of manual pressure release (MPR) and algometer pressure release (APR) on the latent myofascial trigger points (MTrP) of the upper trapezius muscle.

METHODS

In this clinical trial, 40 patients with latent MTrP of the upper trapezius were randomly allocated to the MPR (n: 20) or APR groups (n: 20). Treatments were applied for 5 sessions over 2 weeks. Pain, neck range of motion, pressure pain threshold, and morphometric indications were examined using a visual analog scale, goniometry, algometer, and ultrasonography, respectively. Ultrasonography was used to evaluate the penetration angle, muscle thickness, L-mean (muscle echogenicity), and standard deviation of echogenicity. Before treatment, at the end of the fifth session, and 2 weeks following the intervention (follow-up session), measurements were taken at rest and during contraction of the upper trapezius muscle at 90°of shoulder abduction.

RESULTS

At the end of treatment (P = 0.012) and follow-up session (P = 0.015), the pressure-pain threshold was significantly higher in the APR group than in the MPR group. In contrast, the penetration angle at rest (P = 0.005) and during contraction (P = 0.003) and the L-mean during contraction (P = 0.004) were significantly reduced in the MPR group compared with the APR group.

CONCLUSION

The APR approach assisted in raising the pressure pain threshold, whereas the MPR technique was more efficient at enhancing the morphological markers of the upper trapezius with latent MTrp.