BACKGROUND: Prolonged sitting leads to low back discomfort and lumbopelvic muscle fatigue. This study examined the characteristics of body perceived discomfort and trunk muscle fatigue during 1 hour of sitting in three postures in office workers. METHODS: Thirty workers sat for 1 hour in one of three sitting postures (i.e., upright, slumped, and forward leaning postures). Body discomfort was assessed using the Body Perceived Discomfort scale at the beginning and after 1 hour of sitting. Electromyographic (EMG) signals were recorded from superficial lumbar multifidus, iliocostalis lumborum pars thoracis, internal oblique (IO)/transversus abdominis (TrA), and rectus abdominis muscles during 1 hour of sitting. The median frequency (MDF) of the EMG power spectrum was calculated. RESULTS: Regardless of the sitting posture, the Body Perceived Discomfort scores in the neck, shoulder, upper back, low back, and buttock significantly increased after 1 hour of sitting compared with baseline values (t(9) = -11.97 to -2.69, p < 0.05). The MDF value of the EMG signal of rectus abdominis, iliocostalis lumborum pars thoracis, and multifidus muscles was unchanged over time in all three sitting postures. Only the right and left IO/TrA in the slumped sitting posture was significantly associated with decreased MDF over time (p = 0.019 to 0.041). CONCLUSION: Prolonged sitting led to increased body discomfort in the neck, shoulder, upper back, low back, and buttock. No sign of trunk muscle fatigue was detected over 1 hour of sitting in the upright and forward leaning postures. Prolonged slumped sitting may relate to IO/TrA muscle fatigue, which may compromise the stability of the spine, making it susceptible to injury.
Buttocks ; Electromyography ; Muscle Fatigue* ; Muscles ; Neck ; Paraspinal Muscles ; Posture* ; Rectus Abdominis ; Shoulder ; Spine

This randomized control pilot study quantified the efficacy of interactive virtual reality golf training on balance performance among community mobile older person. Eight older women were assigned randomly to a conventional mat exercises program group (n = 4, mean age = 51 ± 1.6 years old) or an experimental group that participated in interactive virtual reality golf (n = 4, mean age = 53.5 ± 1.4 years old). Balance assessments of all participants included Multi-Directional Reach Test (MDRT), Step Up Test (SUT), Double Leg Static Balance (DLSB) with eyes open and closed and excursion of centre of pressure (COP) sway quantified with a force plate. One subject dropped out from the experimental group and three subjects from the conventional mat exercise group due to work commitments to complete the once a week study for four weeks. No significant differences in base-line balance abilities were found between groups. The experiment group did not have significant improvements in balance capability compared with control subjects (MDRT p = 0.16-0.66; SUT p = 0.05; COP during DLSB p = 0.18-0.66). However, virtual reality golf intervention improved medial-lateral sway by 57.24% during DLSB compared to 14.99% after floor-mat exercises. The improvement in COP during DLSB after interactive virtual reality golf hints towards improved postural control. Further studies with a larger population should explore using off-the shelf interactive virtual reality sports for balance training. This novel technology can complement rehabilitation programs.

Physical Activity Scale for the Elderly (PASE) is a simple, valid and reliable questionnaire that can be administered to quantify older adults’ physical activity levels during daily living. However, PASE in Malay language for use among older population is not available. The objective of our current study was to evaluate the reliability and validity of the Malay translated Physical Activity Scale for Elderly (PASE-M) for the use among older adults. Objective results of physical activity were obtained by wearing continuously an accelerometer for one week among a population of older adults in Malaysia who speak Malay language. Participants completed PASE-M twice, on day-8 (PASE-M1) and day-15 (PASE-M2). Concurrent validity between PASE-M1 and accelerometer results was assessed using Spearman’s rank correlation coefficient. Test-retest reliability for one week interval of PASE-M was tested using Spearman’s rank correlation coefficient and Intra-class correlation coefficients (ICC). Forty-four community-dwelling older adults (12 men and 32 women; mean age ± SD= 66.95 ± 5.34) participated in this study. However, only 33 participants (8 men and 25 women; mean age ± SD= 66.64 ± 5.51) were able to achieve the minimum accelerometer wearing time and filled up the PASE-M questionnaire for two times with one weeks interval. The results showed the PASE-M score was significantly correlated with vector magnitude (VM) counts (r=0.54, p<0.01), time in moderate-to-vigorous physical activity (MVPA) (r =0.55, p<0.01), energy expenditure (r =0.53, p<0.01) and walking steps (r=0.39, p<0.05). A high reliability (ICC = 0.96) was demonstrated between first and the subsequent administration of PASE-M (p<0.01, 95% CI: 0.92-0.98). The PASE-M is a valid and reliable questionnaire to assess physical activity level for Malaysian community-dwelling older adults.
older adults, physical activity, questionnaire, accelerometer, validity, reliability

There is limited information regarding gender differences in spinal morphological attributes among healthy young adultsalthough alterations have been reported to influence postural changes, mainly with forward-bending and extensionpostures. The aim of this preliminary study was to examine gender differences in spinal morphological attributes oflumbar extensor muscles that includes its muscle fibre angles, thickness, endurance and thoracolumbar curvature amongyoung adults. Nineteen male and 26 female healthy young adults (aged 21-24 years) matched for age, body mass indexand physical activity levels participated in this preliminary study. Fibre angles and thickness of lumbar extensor muscleswere examined using ultrasonography. Lumbar extensor muscle endurance and thoracolumbar curvatures were assessedusing Sorenson’s test and a flexible ruler respectively. Paired t-test showed a significant mean difference (p < 0.01)between the right and left fibre angles. However, no significant mean difference (p = 0.50) was found between the rightand left muscle thickness. Results of independent t-test showed a significant difference (p < 0.01) in muscle thicknessbetween males and females. No significant differences were shown in right fibre angle (p = 0.12), left fibre angle (p =0.89), muscle endurance (p = 0.46), thoracic curvature (p = 0.76) and lumbar curvature (p = 0.06) between genders.There were no gender differences in spinal morphological attributes except for lumbar extensor muscle thickness inyoung adults age between 21 to 24. This study data may be useful as an initial reference norm of spinal morphologicalattributes among young adults. Further studies may be required to examine the factors that may influence changes inspinal morphological attributes among healthy adults.