2012 journal article

Effects of handicraft sitting postures on lower trunk muscle fatigue

ERGONOMICS, 55(6), 693–703.

co-author countries: Thailand 🇹🇭 United States of America 🇺🇸
author keywords: trunk muscle fatigue; body discomfort; surface electromyography; visual analogue scale; normalised median frequency slope
MeSH headings : Aged; Analysis of Variance; Confidence Intervals; Electromyography / instrumentation; Ergonomics / instrumentation; Female; Humans; Linear Models; Male; Middle Aged; Muscle Fatigue; Muscle, Skeletal / physiology; Occupational Exposure / adverse effects; Occupational Health; Pain Measurement; Posture / physiology; Risk Factors; Statistics as Topic
Source: Web Of Science
Added: August 6, 2018

The purpose of this study was to assess trunk muscle fatigue in seated handicraft tasks using surface electromyography (sEMG) and visual analogue scale (VAS) ratings for trunk discomfort, and to assess the relationship of these responses. Twenty-three participants were randomly assigned to assumed crossed-leg and heel sitting postures for 30 min. Normalised median frequency (NMF) slopes for lumbar multifidus (LM) and internal oblique (IO) muscles and VAS ratings were recorded. Results revealed that the crossed-leg posture produced significantly steeper NMF slopes for both sides of the LM and IO muscles than heel sitting. Greater VAS ratings were found in crossed-leg sitting posture than the heel sitting posture. The NMF slopes and the VAS ratings had significant negative correlations for both postures. Findings support heel sitting in handicraft tasks over crossed-leg sitting due to greater trunk muscle fatigue and discomfort during the latter posture. Results support VAS ratings as a complementary method to sEMG for identifying trunk muscle fatigue.