Sawitri Wanpen

Effects of handicraft sitting postures on lower trunk muscle fatigue

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. Practitioner Summary: Trunk muscle fatigue in handicraft work is a potential risk for low back pain. Based on EMG and discomfort analyses, heel sitting is preferred to crossed-leg posture. Discomfort ratings are consistent with EMG measures in identifying trunk muscle fatigue in such postures.

Effects of mechanical-bed massage on exercise-induced back fatigue in athletes

[Purpose] The study aimed to preliminarily investigate the effects of mechanical-bed massage on exercise-induced back fatigue in athletes. [Subjects and Methods] Twelve male college athletes, randomly allocated to experimental or control groups, were instructed to perform reverse sit-up for 8 sessions until they became fatigued. The experimental group received a 20-min mechanical-bed massage session, while the control group rested on a bed for the same period of time. Visual Analogue Scale (VAS) on perceived back muscle fatigue, back muscle endurance, and Heart Rate Variability (HRV) parameters including stress index (SI), HRV index, SDNN, RMSSD, pNN50, LF, HF, and LF/HF were analyzed. [Results] Immediately and 24 hours after the intervention, the VAS significantly differed between the groups. Experimental group’s HF was significantly higher immediately after the intervention than control group. Experimental group’s LF and LF/HF were significantly lower immediately after the intervention than the control group. [Conclusion] Mechanical bed massage may help athletes overcome the subjective feelings of exercise-induced fatigue, modulate the automatic nervous system activity, especially for balancing sympathetic and parasympathetic activities. Therefore, mechanical bed massage may facilitate recovery from muscle and central fatigue after athlete training or competition.

Effects of Treadmill Running Between Novices and Experienced Runners on Total Range of Lumbar Flexion and Lumbar Extension

This research was an experimental study. The aim of this study was to investigate the effects of treadmill running to total range of lumbar flexion and lumbar extension between novices and experienced runners. Ten novices and ten experienced healthy male runners, aged between 20 and 39 years. Each subject was measured their spinal range of motion in total lumbar flexion and total lumbar extension using an inclinometer, before and after a period of intervention. Each subject was asked to run on the treadmill for 30 minutes. The findings showed that range of motion in total lumbar flexion was significantly increased after performing the treadmill running in both groups (P < 0.001, P = 0.03), however there was no * iA“∫—≥±‘μ A≈—° Ÿμ√«‘∑¬“»“ μ√iA“∫—≥±‘μ “¢“«‘TM“°“¬?“ae∫”∫—¥ §≥–‡∑§π‘§°“√·ae∑¬a iA“«‘∑¬“≈—¬¢Oπ·°aπ ** √Os»“ μ√“®“√¬a °≈yai«‘®—¬a«¥A≈—s a«¥§O ·≈–a«¥¢âOO◊EπE §≥–‡∑§π‘§°“√·ae∑¬a iA“«‘∑¬“≈—¬¢Oπ·°aπ *** oŸâTMa«¬»“ μ√“®“√¬a °≈yai«‘®—¬a«¥A≈—s a«¥§O ·≈–a«¥¢âOO◊EπE §≥–‡∑§π‘§°“√·ae∑¬a iA“«‘∑¬“≈—¬¢Oπ·°aπ 42 «“√ “√«‘®—¬ i¢. (∫».) 9 (4) : μ.§. ∏.§. 2552