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

Abstract

ObjectiveThe 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.MethodsNine 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 Fpeakand Fmean.ResultsData for Fpeakdemonstrated 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).ConclusionsClinicians 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.

Implementing A Flexible Sensor to Identify Forces during Instrument-Assisted Soft Tissue Mobilization

“…However, it should be noted that this instrument was selected for its rounded edge beveling which avoided creating a crease in the sensor when it was attached to the instrument. The prior study that used the ELF system also used instruments with rounded edge beveling [14]. Instruments with a sharper beveled edge may not be suitable for the ELF system.…”

“…Following previously established methods [13,14], a skin simulant (SynTissue, Syn-Daver, Tampa, FL, USA) was attached to a force plate (HE6X6, AMTI, Watertown, MA, USA) and used to obtain the resultant force readings from the combined x (anterior/posterior), y (horizontal), and z (vertical) vectors during a simulated IASTM treatment using the following formula:…”

“…The Economical Load and Force (ELF) measurement system is a flexible pressure sensor that can be easily attached to commercially available IASTM products and may be an economical option for measuring IASTM forces in human trials. Prior to the current study, the ELF system has been used in one human trial [12] and the forces found with the ELF measurement system were similar to the forces found in force plate studies [13,14]. However, the methods of instrument calibration were not included within the prior study and it is unknown how the forces measured with the ELF measurement system relate to those measured on a force plate.…”

“…Simulated treatment scenarios have also found that trained clinicians can be reliable when applying forces across days when using instruments of different sizes, shapes, and weights [15]. Interestingly, findings from simulated treatment studies have also indicated the potential for different instruments and grip types (i.e., one versus two-handed grips) to impact the amount of force being applied over a single simulated treatment session [14]. Although this initial information is valuable for the current understanding of how much force patients may be receiving in practice, these simulations were unable to account for variability that occurs due to the different shapes and tissue types that make up the human anatomy.…”

“…Initial efforts to quantify IASTM forces used by trained clinicians have been conducted on simulated tissue attached to a force plate: one-handed IASTM strokes resulted in 2.6 to 14.0 N for peak forces and 1.6 to 10.0 N for average force across clinicians [13], while two-handed IASTM stroke forces ranged from 1.1 to 21.3 N for average peak force and 0.9 to 15.3 N for average mean force across clinicians [14]. Simulated treatment scenarios have also found that trained clinicians can be reliable when applying forces across days when using instruments of different sizes, shapes, and weights [15].…”