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

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 (F(peak)) and mean (F(mean)) 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 F(peak) and F(mean). RESULTS: Data for F(peak) demonstrated a significant main effect for grip type (F((1, 8))=46.39, p<0.001, [Formula: see text] =0.34), instrument (F((4, 32))=4.61, p=0.005, [Formula: see text] =0.06) and interaction (F((2, 16))=10.23, p=0.001, [Formula: see text] =0.07). For F(mean), there was also a statistically significant main effect for grip type (F((1, 8))=60.47, p<0.001, [Formula: see text] =0.32), instrument (F((4, 32))=4.03, p=0.009, [Formula: see text] =0.06) and interaction (F((2, 19))=7.92, p=0.002, [Formula: see text] =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.