Effect of instrument type and one-handed versus two-handed grips on force application during simulated instrument-assisted soft tissue mobilisation

Abstract

Objective The purpose of this study was to examine whether the forces used by trained clinicians during a simulated instrument-assisted soft tissue mobilisation (IASTM) treatment varied across five different instruments during one-handed and two-handed IASTM grips.Methods Nine athletic trainers who previously completed IASTM training and used the technique in professional practice were included in the study. A skin simulant was attached to a force plate and used to evaluate force production during a simulated IASTM treatment scenario. Peak (Fpeak) and mean (Fmean) forces were recorded for both one-handed and two-handed grips for each participant across the five instruments. Data were analysed using separate 2 (grip type) × 5 (IASTM instrument) repeated measures analysis of variance for both Fpeak and Fmean.Results Data for Fpeak demonstrated a significant main effect for grip type (F(1, 8)=46.39, p<0.001, ηp2 =0.34), instrument (F(4, 32)=4.61, p=0.005, ηp2 =0.06) and interaction (F(2, 16)=10.23, p=0.001, ηp2 =0.07). For Fmean, there was also a statistically significant main effect for grip type (F(1, 8)=60.47, p<0.001, ηp2 =0.32), instrument (F(4, 32)=4.03, p=0.009, ηp2 =0.06) and interaction (F(2, 19)=7.92, p=0.002, ηp2 =0.06).Conclusions Clinicians produced greater IASTM forces when applying a two-handed grip than a one-handed grip. Instrument weight may matter less than instrument shape, size and bevelling for influencing force production as instrument length appears to influence force production when using one-handed or two-handed grips. Although the effects of IASTM force variation on patient outcomes remains unknown, these findings may be considered by clinicians when making instrument and grip choices.