Instrument-Assisted Soft Tissue Mobilization 2-Handed Grip Force Production Consistency During Simulated Treatment: A Technical Report

Context: Instrument-assisted soft tissue mobilization (IASTM) continues to increase in popularity and utilization among manual therapists. Despite its popularity, little is known about the consistency in peak or average forces that clinicians apply when performing IASTM treatments with a 2-handed grip. The purpose of this study was to examine intraclinician consistency in peak and average forces when applying a 2-handed IASTM grip. Design: Randomized crossover study conducted in a university biomechanics laboratory. Methods: Five (5) licensed athletic trainers with prior IASTM training used 5 different IASTM instruments to apply simulated treatment. Average peak forces (Fpeak) and average mean forces (Fmean) were collected via force plate for all 5 IASTM instruments with a skin simulant attached. Descriptive statistics, coefficients of variation (CVs), box and density plots, and Bland-Altman plots were assessed. Results: The clinicians' average Fpeak ranged from 3.0 N to 11.6 N and average Fmean from 1.9 N to 8.1 N. Fpeak CVs for all instruments ranged from 14% to 31%, and Fmean CVs ranged from 15% to 35%. Bland-Altman plots indicated that for both Fpeak and Fmean, 97% of the data points fell within the limits of agreement across instruments and clinicians. Mean differences across instruments ranged from 0.9 N (91.8 g) to 4.1 N (418.1 g) for Fpeak and from 1.0 N (102.0 g) to 2.8 N (285.5 g) for Fmean. Thus, CVs, box and density plots, and Bland-Altman plots supported general force application consistency. Conclusion: Trained IASTM clinicians produced consistent treatment application forces (ie, Fpeak and Fmean) within treatment sessions during 2-handed simulated application.