Montakarn Chaikumarn

Participatory Ergonomics and an Evaluation of a Low-Cost Improvement Effect on Cleaners' Working Posture

Cleaning is a highly physically demanding job with a high frequency of awkward postures and working environments as contributing risk factors. Participatory ergonomics is a method in which end-users take an active role in identifying risk factors and solutions. The aim of this study was to apply the participatory ergonomics method to identify cleaning problems and to evaluate the effect of a low-cost improvement on cleaners ‘ working postures in an office environment. The results show that the cleaning problem was identified, and the low-cost ergonomics solution suggested by the cleaners was implemented. Thus an improved working environment reduced the number of awkward cleaning postures and the Ovako Working Posture Analysis System (OWAS) action category for floor mopping decreased. It can be concluded that working in an improved environment can lead to better working postures which, in turn, leads to the cleaners’ better health and better cleaning results.

Effect of different types of rest-break interventions on neck and shoulder muscle activity, perceived discomfort and productivity in symptomatic VDU operators: a randomized controlled trial.

Objective. This study evaluated the effect of different types of activities during rest-break interventions on neck and shoulder muscle activity, muscle discomfort and productivity among symptomatic video display unit (VDU) operators performing prolonged computer terminal work. Study design and setting. Randomized controlled trial was used. Thirty symptomatic VDU operators were randomly assigned to 2 active break groups (stretching and dynamic movement) and a reference group. The subjects performed the same typing task for 60 min and received 3-min breaks after each 20 min of work. Root mean square and median frequency were calculated for neck and shoulder muscle activity. Muscle discomfort was measured with Borg’s CR-10 scale. Productivity was measured by counting words. Results. There were no significant differences between the types of activities during breaks on neck and shoulder muscle activity, muscle discomfort or productivity. However, there was a significant difference in the level of muscle discomfort over time. Conclusions. Three types of activity during breaks showed a favourable effect on neck and shoulder muscle activity and productivity, and a positive effect on muscle discomfort in symptomatic VDU operators.

Differences in Dentists’ Working Postures When Adopting Proprioceptive Derivation vs. Conventional Concept

New technologies and changes in dental care, including the proprioceptive derivation (Pd) concept, aimed at providing dentists with greater comfort and better health, were introduced in Thailand. The aim of this study was to investigate the differences in dentists’ working postures when adopting different work concepts: Pd and the conventional concept. The results showed differences in dentists’ sitting posture, clock-related working positions, and Rapid Upper Limb Assessment (RULA) scores. This implied that Pd helped dentists to discover new ways of positioning themselves, and working comfortably and effectively, which made it possible for them to adopt better working posture and have lower RULA scores. In conclusion, the Pd concept had a positive effect on dentists’ working posture.

Prevalence of self-reported musculoskeletal symptoms in salespersons.

BACKGROUND Salespersons are required to stand for long periods of time during work. Prolonged standing is one physical factor contributing to the development of musculoskeletal symptoms in the working population. AIMS To estimate the 12-month prevalence of self-reported musculoskeletal symptoms in the head/neck, shoulders, elbows, wrists/hands, upper back, low back, hips, knees and ankles/feet in salespersons. METHODS A cross-sectional survey using a descriptive questionnaire was used to evaluate musculoskeletal symptoms in 1310 female salespersons in 18 department stores. RESULTS Of the 1200 subjects (92%) who completed the questionnaire, 1189 were eligible for inclusion in the study. The 1-year prevalence of self-reported musculoskeletal symptoms was 77%. The ankle/foot (35%) was the most frequently affected body region followed by low back (34%), knees (33%), hips (28%), shoulders (28%), head/neck (26%), upper back (21%), wrists/hands (14%) and elbows (3%). The older the salespersons were, the more likely they were to report knee symptoms (P < 0.05). Salespersons with a body mass index (BMI) >23 kg/m(2) were more likely to report knee symptoms than those with a BMI <18.5 kg/m(2) (P < 0.05). CONCLUSIONS Musculoskeletal symptoms are common among salespersons with a high proportion experiencing symptoms in the low back, knees and ankles/feet. The prevalence of musculoskeletal symptoms in the knees is associated with age and BMI. Attention should be given to developing specific measures to reduce or prevent musculoskeletal symptoms in salespersons.

Biopsychosocial Risk Factors for Musculoskeletal Symptoms of the Spine in Salespeople

Abstract This study aimed to identify biopsychosocial factors associated with the self-reported prevalence of musculoskeletal symptoms in the spine in saleswomen in department stores. A cross-sectional survey was conducted in which 1310 saleswomen in 18 department stores received a self-administered questionnaire. Returns were 1200 (92%) questionnaires, and after screening for exclusion criteria, 1189 saleswomen were eligible for the study. Standing/walking for >10 hours/day, as well as frequent working in static postures and twisting the body during work were each significantly associated with a high prevalence of experiencing head/neck symptoms. A significant association was found between standing/walking for > 10 hours/day and a high prevalence of experiencing upper back symptoms. Working for > 10 hours/day, standing/walking for > 5 hours/day without rest breaks, as well as frequent working in static postures and sitting during work were each significantly related to a high prevalence of experiencing lower back symptoms. Surprisingly, poor self-rated perceptions of physical work environments significantly correlated with a low prevalence of musculoskeletal symptoms in all spinal regions.

Working Conditions and Dentists’ Attitude Towards Proprioceptive Derivation

Proprioceptive derivation (Pd), a new method of organising a dentist workstation as well as a working procedure, was introduced to Thailand. The aim of this study was to assess the working conditions and the attitude to Pd among experienced users. Questionnaires were distributed among 12 dentists. The results showed that all dentists chose to work in a sitting posture and mostly worked without breaks between patients. They spent less time on dental examination and crown and bridge therapy tasks. Solving problems in patients with physical limitations resulted in a low stress level. Seven dentists (58.3%) always used Pd and liked it. Five dentists (41.7%) sometimes used Pd, with 3 of them liking it. Only 2 dentists, who sometimes used Pd, did not like it because it could not cover all dental tasks and treatment, and it was difficult and complex.

Biopsychosocial factors and musculoskeletal symptoms of the lower extremities of saleswomen in department stores in Thailand.

Biopsychosocial Factors and Musculoskeletal Symptoms of the Lower Extremities of Saleswomen in Department Stores in Thailand: Praneet Pensri, et al. Department of Physical Therapy, Faculty of Allied Health Sciences, Chulalongkorn University, Thailand

Impact of rest-break interventions on the neck and shoulder posture of symptomatic VDU operators during prolonged computer work

There is limited research on the effects of different types of rest-break interventions for visual display unit (VDU) operators on neck and shoulder postures. This study examined the effect of rest-break interventions on the neck and shoulder postures of symptomatic VDU operators during prolonged computer work. Thirty subjects were randomly and equally assigned to breaks with stretching, breaks with dynamic movement and passive breaks. Subjects performed the typing task for 60 min and received 3-min breaks after 20 min of work. The craniovertebral and forward shoulder angles were obtained from a 3D motion analysis system. Results showed that there were no significant differences in the craniovertebral and forward shoulder angles among any types of rest breaks. It can be concluded that the three types of rest-break interventions had positive effects on neck and shoulder posture during prolonged computer terminal work.

Repeatability of electromyography normalization of the neck and shoulder muscles in symptomatic office workers

Purpose. The purpose of the study was to examine the repeatability of electromyography (EMG) normalization in office workers with neck and shoulder symptoms. Methods. Fifteen female office workers with neck/shoulder symptoms were recruited to participate in two separate days of testing. Maximum voluntary isometric contraction (MVIC) was used for the normalization of EMG data on the following muscles: cervical erector spinae, upper trapezius, lower trapezius and anterior deltoid. Repeatability was calculated using the intra-class correlation (ICC), relative standard error of measurement (%SEM) and relative coefficient of variation (%CV). Results. Peak root mean square (rms) and median frequency (MF) showed good to high repeatability in the UT, AD and CES (ICC = 0.87–0.95, %SEM= 2.65–9.48, %CV= 0.2–5.9). The repeatability of peak rms was good (ICC = 0.87, %SEM = 12.56, %CV = 3.3) and the MF of the LT was fair (ICC = 0.76, %SEM = 5.71, %CV = 2.9). Conclusion. Peak rms and MF from the MVIC normalization method can be measured with sufficient repeatability in symptomatic office workers.