Morten Wærsted - Academia.edu (original) (raw)
Papers by Morten Wærsted
Norsk Epidemiologi, 2009
A review is presented of epidemiological peer-reviewed publications that relate the mechanical ex... more A review is presented of epidemiological peer-reviewed publications that relate the mechanical exposure of the arm in work with visual display units (VDU) to musculoskeletal disorders of the upper limb. The twenty included studies were divided into those with (1-7) and without (8-21) use of physical examination in the definition of cases. The main conclusion of this review is the documentation of evidence for the VDU work per se, none or insufficient lower arm support and non-neutral positions of the wrist as predictors of distal upper limb disorders (DULDs). These findings are based solely on studies that use physical examination or objective signs to define the DULDs, and the conclusions are not changed after inclusion of studies based only on self-reported symptoms. When the last category of studies is included as documentation in the review, the amount of VDU work (and an exposuredose/effect relationship) will also be documented as predictors. The referred studies indicated that not only the VDU work per se, but also (and in particular) VDU work for more than 20 hours per week combined with limited opportunity for rest breaks and without lower arm support is a predictor of DULDs. Another conclusion is that critical reviews may benefit from use of both strict criteria and less strict criteria for inclusion of studies, to optimize the conclusions drawn from existing documentation.
International Journal of Environmental Research and Public Health, 2016
This study aimed to elucidate cardiovascular loads (CVL) in construction workers during work and ... more This study aimed to elucidate cardiovascular loads (CVL) in construction workers during work and leisure by relative heart rate (RHR) over several days. Furthermore, we sought to evaluate the level of CVL in relation to individual factors, work ability, musculoskeletal pain and subjective general health. From a group of 255 construction workers responding to the baseline questionnaire, the CVL during work and leisure time was determined by recording RHR in 42 workers over 3-4 days. Almost 60% of the workday was spent below 20% RHR. The mean RHR during work for all participants was 16% RHR, with large differences between professions. On average, the 42 workers spent 14% of the workday at a RHR above 33%, and four subjects (10%) had a mean RHR above 33% during work. Eight (19%) of the participants had a mean length of their workday exceeding calculated maximal acceptable work time. Seven persons (17%) experienced on average one or more episode(s) of 5 min or more continuously above 33% RHR. The cardiovascular load at work was significantly associated with age and V ˙O2max, but not with work ability, musculoskeletal pain or subjective general health.
BMC musculoskeletal disorders, 2016
There is a need to investigate the occurrence of multisite pain in young adults and to determine ... more There is a need to investigate the occurrence of multisite pain in young adults and to determine potential factors contributing to the early course of multisite musculoskeletal pain. The aim of this prospective study was to assess the occurrence and change of prevalence in the number of pain sites. We also wanted to identify work-related and individual risk factors associated with the number of musculoskeletal pain sites. We monitored musculoskeletal pain from 4 body regions, individual and work-related factors on 21 occasions over a 6.5 year period. The cohort consisted of 420 technical school students entering working life. Data were analyzed by generalized estimating equations (GEE). Pain from more than one body site was prevalent in this cohort of young adults (69 % at baseline), and the number of body sites in pain was found quite stable over the 6.5 year follow-up period. Women had higher number of pain sites compared with men and gender specific risk factors were identified. ...
BMC Public Health, 2015
The association between leisure time physical activity and low back pain in young adults is uncle... more The association between leisure time physical activity and low back pain in young adults is unclear and is in the need of prospectively obtained evidence. This study examined the course of low back pain and the association between low back pain and leisure time physical activity in a cohort of young adults in their transition from school to working life. Both low back pain and leisure time physical activity was monitored over a 6.5 year period in 420 subjects starting out as students within hairdressing, electrical installation and media/design. The association between physical activity and low back pain was investigated through the follow-up period by using linear mixed models analysis. Low back pain was significantly influenced by time and overall there was a decreasing trend of low back pain prevalence throughout the follow-up. Analysis showed a weak trend of decreasing low back pain with moderate/high physical activity levels, but this association was not significant. Low back pain decreased during follow-up with baseline as reference. Findings in our study did show non-significant trends of reduced low back pain with increased leisure time physical activity. Still, we could not support the theory of moderate/high levels of physical activity acting protective against low back pain in young adults entering working life. Our results, in combination with previous relevant research, cannot support a clear relationship between physical activity and low back pain for young adults. Thus, recommendations regarding effect of physical activity on reducing low back pain for this group are not clear.
Tidsskrift for Den norske legeforening
Recent research indicates that any continuous load on the shoulder and upper limb muscles is a ri... more Recent research indicates that any continuous load on the shoulder and upper limb muscles is a risk factor for occupational muscle pain. When the muscle load is moderate to low, the duration seems far more important than the actual load level, possibly because of a fixed recruitment order of motor units. Research at the Norwegian National Institute of Occupational Health has shown that a mentally challenging task at a visual display terminal may give a low level of muscle activation with apparently no purpose as regards posture or movement ("psychogenic" muscle tension), based on continuous firing in a few motor units. This indicates a possible mechanism for the often observed link between psychosocial stress and muscle pain.
Work (Reading, Mass.), 2012
The aim was to analyze the relationship between periods with uninterrupted neck muscle activity f... more The aim was to analyze the relationship between periods with uninterrupted neck muscle activity for ≥ 4 min and neck and shoulder pain. The trapezius muscle activity was recorded bilaterally on 40 young workers and students during a full shift. Neck and shoulder pain, mechanical work load and decision control were reported at the same time as the muscle activity recording and 6 months later. A dose-response relationship was found between uninterrupted muscle activity and neck and shoulder pain, with a ten-fold higher risk for the group with more than half, compared to less than a third, of the shift with uninterrupted muscle activity. Self-reported mechanical work load showed a small but protective effect related to pain. Gender and decision control did not emerge as important risk factors in this model. In conclusion, this study indicates that work or other exposures that contains long periods with uninterrupted neck muscle activity of 4 min duration or longer should be minimized t...
Journal of occupational medicine and toxicology (London, England), 2006
This study examined the association between psychosocial and organizational work conditions and m... more This study examined the association between psychosocial and organizational work conditions and mental health among women employed in the cleaning profession in Norway. Self-report questionnaires were mailed to 661 cleaning staff personnel from seven cleaning organizations in seven different cities across Norway. The response rate was 64%, of which 374 (88%) respondents were women. The questionnaires assessed socio-demographic information and employment history, work organization, and psychosocial working conditions. The Hopkins Symptoms Checklist (HSCL-25) was included to assess mental health. On average, respondents were 43 years old and reported 10.8 years of experience working in the cleaning industry. The proportion of women scoring a HSCL-25 equal to or above 1.75 was 17.5%, which was higher than the average prevalence of mental health problems among working Norwegian women (8.4%). A factor analysis of the questions specific to the psychosocial work environment identified the ...
Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, Jan 20, 1994
It is suggested that occupational exposure to muscle load should be described by three factors to... more It is suggested that occupational exposure to muscle load should be described by three factors to indicate health risks: level, repetitiveness and duration. A reduction in level is beneficial if the level is high (> 10-15% MVC). However, even a low level involves risk of musculoskeletal complaints if the exposure is repetitive. A reduction of the occupational exposure from 7-8 hours to 4-5 hours per day delays the development of musculoskeletal complaints, but does not provide long-term reduction of risk with frequent repetitions. When interventions are carried out to reduce the risk of occupational musculoskeletal complaints, it is necessary to consider psychosocial and individual constitutional factors in addition to the three factors constituting the occupational exposure to muscle load.
Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 2000
The following articles refer to this text: 2010;36(1):3-24 2010;36(1):1-2
Applied Ergonomics, 2015
This prospective study aimed at examining if work with prolonged arm elevation predicts shoulder ... more This prospective study aimed at examining if work with prolonged arm elevation predicts shoulder pain among 41 young adults in their first years of working life. Fifteen hairdressers, 15 electricians, 5 students and 6 with various work were followed over a 2.5-year period (2006/7e2009). Arm elevation was measured with inclinometers during a full working day at baseline. Shoulder pain was reported at baseline and twice in the follow-up period. Data were analyzed by generalized estimating equations (GEE-analysis), stratified by gender and adjusted for time, mechanical workload, work demand, physical activity, tobacco use and prior shoulder pain. Work with prolonged arm elevation with angles >60 and >90 were associated with shoulder pain among women. Even though the shoulder pain levels are low the study suggests work with arms elevated as an early work-related risk factor among women, and indicates the importance of early prevention strategies.
European Journal of Physiotherapy, 2013
ABSTRACT Purpose: To study the association between self-reported general tension and muscle tensi... more ABSTRACT Purpose: To study the association between self-reported general tension and muscle tension, and clinically tested relaxation ability. Methods: Self-reports on muscle tension habits and on general tension, and the covariates neck and shoulder pain, perceived stress level, perceived mastery of work, quantitative work demands, and leisure time physical activity, were collected on a questionnaire (52 males, 81 females, mean age 23 years). A clinical test on relaxation ability was performed by a trained physiotherapist on a subsample (38 males, 39 females). Results: Perceived general tension showed a highly significant (p < 0.001) correlation with the muscle tension habit score (0.58), and the muscle tension factor (0.54). None of the self-reported tension measures correlated with the relaxation ability score. The self-reported tension measures, but not the clinical tension score, showed an association with neck and shoulder pain and perceived stress level. Conclusions: The self-reported measures of general tension and of muscle tension correlated and probably represented similar phenomenon. However, the subjects’ perceived stress level was to a higher degree reflected in the measure of general tension. The score of the clinical test on relaxation ability did not show an association with the self-reported tension measures.
BMC Public Health, 2014
Background: Musculoskeletal disorders have a profound impact on individual health, sickness absen... more Background: Musculoskeletal disorders have a profound impact on individual health, sickness absence and early retirement, particularly in physically demanding occupations. Demographics are changing in the developed countries, towards increasing proportions of senior workers. These senior workers may have particular difficulties coping with physically demanding occupations while maintaining good health. Previous studies investigating the relationship between physical work demands and musculoskeletal disorders are mainly based on self-reported exposures and lack a prospective design. The aim of this paper is to describe the background and methods and discuss challenges for a field study examining physical demands in construction and health care work and their prospective associations with musculoskeletal disorders, work ability and sickness absence.
Scandinavian Journal of Work, Environment & Health, 2014
A longitudinal study on risk factors for neck and shoulder pain among young adults in the transit... more A longitudinal study on risk factors for neck and shoulder pain among young adults in the transition from technical school to working life by Hanvold TN, Waersted M, Mengshoel AM, Bjertness E, Twisk J, Veiersted KB
Scandinavian Journal of Work, Environment & Health, 2013
The results indicate that sustained trapezius muscle activity with periods of more than 4 minutes... more The results indicate that sustained trapezius muscle activity with periods of more than 4 minutes duration for more than half of the working day, increases the rate of neck and shoulder pain in a 2.5-year period. This implicates the importance of reducing the lengths of periods with sustained muscle activity at work. Hanvold TN, Waersted M, Mengshoel AM, Bjertness E, Stigum H, Twisk J, Veiersted KB. The effect of work-related sustained trapezius muscle activity on the development of neck and shoulder pain among young adults. Scand J Work Environ Health -online first.
Journal of Occupational and Environmental Medicine, 2013
To examine the effect of sex and socioeconomic position (SEP) on individuals' perceptions of pain... more To examine the effect of sex and socioeconomic position (SEP) on individuals' perceptions of pain and its work-relatedness. Methods: We compared self-reported pain in neck-shoulder or arm with clinical diagnoses and workers' judgments of work-relatedness with physicians' assessments based on specific criteria, between sexes and high-and low-SEP participants in the Oslo Health Study (n = 217). Results: Clinical diagnoses were more frequent in low-SEP subjects than high-SEP subjects with pain and generally higher in women than in men. Pain attributed to work was more frequently assessed as work-related by the physicians in low-SEP subjects than high-SEP subjects and in men than in women of low SEP. Conclusions: The threshold for reporting pain seemed higher in low-SEP subjects and among women. Physicians were more likely to agree with low-SEP workers about work-relatedness.
Journal of Adolescent Health, 2010
Purpose: The aim of this prospective study was to relate the prevalence of neck, shoulder, and up... more Purpose: The aim of this prospective study was to relate the prevalence of neck, shoulder, and upper back pain to occupational and individual risk factors among a population of technical school students in their transition from school to working life. In addition, we wanted to assess the changes in pain prevalence during follow-up. Methods: A cohort consisting of 173 technical school students was followed up during a 3-year period, from their last year of school through their first years of working life. Data on self-reported neck, shoulder, and upper back pain and factors such as mechanical exposure, perceived stress, and physical activity in leisure time were collected. Results: A high prevalence of pain in the neck, shoulder, and upper back among the technical school students was found. There were however few students reporting severe pain. Reporting pain at baseline gave over three times higher risk of reporting it at follow-up. A high level of physical activity outside working hours gave a lower risk of reporting neck, shoulder, and upper back pain at follow-up. High and moderate levels of mechanical exposure and high stress level were not found to be risk factors for pain after entering working life. Conclusion: Neck, shoulder, and upper back pain are common among adolescents and may persist into working life. These results may give potential for preventive efforts at a young age. There is still much uncertainty about the factors leading to musculoskeletal pain, and more research is needed on this topic. Ó
International Journal of Industrial Ergonomics, 1997
Body posture and trapezius EMG activity of twelve subjects were evaluated in an experimental VDU-... more Body posture and trapezius EMG activity of twelve subjects were evaluated in an experimental VDU-based work task and a paper-based task with the same work content. Work pace was faster with maintained quality (number of errors not significantly changed) in the VDU version of the work task. The seated posture was more upright. A low-level static EMG activity component was present most of the work time in both versions of the task. The EMG activity level was similar or decreased in the VDU version. Both the posture and the EMG activity showed significantly less variation in the VDU version. It is hypothesized that the decreased variation of physiological load patterns (posture and EMG), when a work task is transformed from paper-based to VDU-based, can be a risk factor for musculoskeletal complaints.
European Journal of Applied Physiology and Occupational Physiology, 1996
Activity of single motor units in relation to surface electromyography (EMG) was studied in 11 su... more Activity of single motor units in relation to surface electromyography (EMG) was studied in 11 subjects in attention-demanding work tasks with minimal requirement of movement. In 53 verified firing periods, single motor units fired continuously from 30 s to 10 min (duration of the experiment work task) with a stable median firing rate in the range of 8–13 Hz. When
Norsk Epidemiologi, 2009
A review is presented of epidemiological peer-reviewed publications that relate the mechanical ex... more A review is presented of epidemiological peer-reviewed publications that relate the mechanical exposure of the arm in work with visual display units (VDU) to musculoskeletal disorders of the upper limb. The twenty included studies were divided into those with (1-7) and without (8-21) use of physical examination in the definition of cases. The main conclusion of this review is the documentation of evidence for the VDU work per se, none or insufficient lower arm support and non-neutral positions of the wrist as predictors of distal upper limb disorders (DULDs). These findings are based solely on studies that use physical examination or objective signs to define the DULDs, and the conclusions are not changed after inclusion of studies based only on self-reported symptoms. When the last category of studies is included as documentation in the review, the amount of VDU work (and an exposuredose/effect relationship) will also be documented as predictors. The referred studies indicated that not only the VDU work per se, but also (and in particular) VDU work for more than 20 hours per week combined with limited opportunity for rest breaks and without lower arm support is a predictor of DULDs. Another conclusion is that critical reviews may benefit from use of both strict criteria and less strict criteria for inclusion of studies, to optimize the conclusions drawn from existing documentation.
International Journal of Environmental Research and Public Health, 2016
This study aimed to elucidate cardiovascular loads (CVL) in construction workers during work and ... more This study aimed to elucidate cardiovascular loads (CVL) in construction workers during work and leisure by relative heart rate (RHR) over several days. Furthermore, we sought to evaluate the level of CVL in relation to individual factors, work ability, musculoskeletal pain and subjective general health. From a group of 255 construction workers responding to the baseline questionnaire, the CVL during work and leisure time was determined by recording RHR in 42 workers over 3-4 days. Almost 60% of the workday was spent below 20% RHR. The mean RHR during work for all participants was 16% RHR, with large differences between professions. On average, the 42 workers spent 14% of the workday at a RHR above 33%, and four subjects (10%) had a mean RHR above 33% during work. Eight (19%) of the participants had a mean length of their workday exceeding calculated maximal acceptable work time. Seven persons (17%) experienced on average one or more episode(s) of 5 min or more continuously above 33% RHR. The cardiovascular load at work was significantly associated with age and V ˙O2max, but not with work ability, musculoskeletal pain or subjective general health.
BMC musculoskeletal disorders, 2016
There is a need to investigate the occurrence of multisite pain in young adults and to determine ... more There is a need to investigate the occurrence of multisite pain in young adults and to determine potential factors contributing to the early course of multisite musculoskeletal pain. The aim of this prospective study was to assess the occurrence and change of prevalence in the number of pain sites. We also wanted to identify work-related and individual risk factors associated with the number of musculoskeletal pain sites. We monitored musculoskeletal pain from 4 body regions, individual and work-related factors on 21 occasions over a 6.5 year period. The cohort consisted of 420 technical school students entering working life. Data were analyzed by generalized estimating equations (GEE). Pain from more than one body site was prevalent in this cohort of young adults (69 % at baseline), and the number of body sites in pain was found quite stable over the 6.5 year follow-up period. Women had higher number of pain sites compared with men and gender specific risk factors were identified. ...
BMC Public Health, 2015
The association between leisure time physical activity and low back pain in young adults is uncle... more The association between leisure time physical activity and low back pain in young adults is unclear and is in the need of prospectively obtained evidence. This study examined the course of low back pain and the association between low back pain and leisure time physical activity in a cohort of young adults in their transition from school to working life. Both low back pain and leisure time physical activity was monitored over a 6.5 year period in 420 subjects starting out as students within hairdressing, electrical installation and media/design. The association between physical activity and low back pain was investigated through the follow-up period by using linear mixed models analysis. Low back pain was significantly influenced by time and overall there was a decreasing trend of low back pain prevalence throughout the follow-up. Analysis showed a weak trend of decreasing low back pain with moderate/high physical activity levels, but this association was not significant. Low back pain decreased during follow-up with baseline as reference. Findings in our study did show non-significant trends of reduced low back pain with increased leisure time physical activity. Still, we could not support the theory of moderate/high levels of physical activity acting protective against low back pain in young adults entering working life. Our results, in combination with previous relevant research, cannot support a clear relationship between physical activity and low back pain for young adults. Thus, recommendations regarding effect of physical activity on reducing low back pain for this group are not clear.
Tidsskrift for Den norske legeforening
Recent research indicates that any continuous load on the shoulder and upper limb muscles is a ri... more Recent research indicates that any continuous load on the shoulder and upper limb muscles is a risk factor for occupational muscle pain. When the muscle load is moderate to low, the duration seems far more important than the actual load level, possibly because of a fixed recruitment order of motor units. Research at the Norwegian National Institute of Occupational Health has shown that a mentally challenging task at a visual display terminal may give a low level of muscle activation with apparently no purpose as regards posture or movement ("psychogenic" muscle tension), based on continuous firing in a few motor units. This indicates a possible mechanism for the often observed link between psychosocial stress and muscle pain.
Work (Reading, Mass.), 2012
The aim was to analyze the relationship between periods with uninterrupted neck muscle activity f... more The aim was to analyze the relationship between periods with uninterrupted neck muscle activity for ≥ 4 min and neck and shoulder pain. The trapezius muscle activity was recorded bilaterally on 40 young workers and students during a full shift. Neck and shoulder pain, mechanical work load and decision control were reported at the same time as the muscle activity recording and 6 months later. A dose-response relationship was found between uninterrupted muscle activity and neck and shoulder pain, with a ten-fold higher risk for the group with more than half, compared to less than a third, of the shift with uninterrupted muscle activity. Self-reported mechanical work load showed a small but protective effect related to pain. Gender and decision control did not emerge as important risk factors in this model. In conclusion, this study indicates that work or other exposures that contains long periods with uninterrupted neck muscle activity of 4 min duration or longer should be minimized t...
Journal of occupational medicine and toxicology (London, England), 2006
This study examined the association between psychosocial and organizational work conditions and m... more This study examined the association between psychosocial and organizational work conditions and mental health among women employed in the cleaning profession in Norway. Self-report questionnaires were mailed to 661 cleaning staff personnel from seven cleaning organizations in seven different cities across Norway. The response rate was 64%, of which 374 (88%) respondents were women. The questionnaires assessed socio-demographic information and employment history, work organization, and psychosocial working conditions. The Hopkins Symptoms Checklist (HSCL-25) was included to assess mental health. On average, respondents were 43 years old and reported 10.8 years of experience working in the cleaning industry. The proportion of women scoring a HSCL-25 equal to or above 1.75 was 17.5%, which was higher than the average prevalence of mental health problems among working Norwegian women (8.4%). A factor analysis of the questions specific to the psychosocial work environment identified the ...
Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, Jan 20, 1994
It is suggested that occupational exposure to muscle load should be described by three factors to... more It is suggested that occupational exposure to muscle load should be described by three factors to indicate health risks: level, repetitiveness and duration. A reduction in level is beneficial if the level is high (> 10-15% MVC). However, even a low level involves risk of musculoskeletal complaints if the exposure is repetitive. A reduction of the occupational exposure from 7-8 hours to 4-5 hours per day delays the development of musculoskeletal complaints, but does not provide long-term reduction of risk with frequent repetitions. When interventions are carried out to reduce the risk of occupational musculoskeletal complaints, it is necessary to consider psychosocial and individual constitutional factors in addition to the three factors constituting the occupational exposure to muscle load.
Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 2000
The following articles refer to this text: 2010;36(1):3-24 2010;36(1):1-2
Applied Ergonomics, 2015
This prospective study aimed at examining if work with prolonged arm elevation predicts shoulder ... more This prospective study aimed at examining if work with prolonged arm elevation predicts shoulder pain among 41 young adults in their first years of working life. Fifteen hairdressers, 15 electricians, 5 students and 6 with various work were followed over a 2.5-year period (2006/7e2009). Arm elevation was measured with inclinometers during a full working day at baseline. Shoulder pain was reported at baseline and twice in the follow-up period. Data were analyzed by generalized estimating equations (GEE-analysis), stratified by gender and adjusted for time, mechanical workload, work demand, physical activity, tobacco use and prior shoulder pain. Work with prolonged arm elevation with angles >60 and >90 were associated with shoulder pain among women. Even though the shoulder pain levels are low the study suggests work with arms elevated as an early work-related risk factor among women, and indicates the importance of early prevention strategies.
European Journal of Physiotherapy, 2013
ABSTRACT Purpose: To study the association between self-reported general tension and muscle tensi... more ABSTRACT Purpose: To study the association between self-reported general tension and muscle tension, and clinically tested relaxation ability. Methods: Self-reports on muscle tension habits and on general tension, and the covariates neck and shoulder pain, perceived stress level, perceived mastery of work, quantitative work demands, and leisure time physical activity, were collected on a questionnaire (52 males, 81 females, mean age 23 years). A clinical test on relaxation ability was performed by a trained physiotherapist on a subsample (38 males, 39 females). Results: Perceived general tension showed a highly significant (p < 0.001) correlation with the muscle tension habit score (0.58), and the muscle tension factor (0.54). None of the self-reported tension measures correlated with the relaxation ability score. The self-reported tension measures, but not the clinical tension score, showed an association with neck and shoulder pain and perceived stress level. Conclusions: The self-reported measures of general tension and of muscle tension correlated and probably represented similar phenomenon. However, the subjects’ perceived stress level was to a higher degree reflected in the measure of general tension. The score of the clinical test on relaxation ability did not show an association with the self-reported tension measures.
BMC Public Health, 2014
Background: Musculoskeletal disorders have a profound impact on individual health, sickness absen... more Background: Musculoskeletal disorders have a profound impact on individual health, sickness absence and early retirement, particularly in physically demanding occupations. Demographics are changing in the developed countries, towards increasing proportions of senior workers. These senior workers may have particular difficulties coping with physically demanding occupations while maintaining good health. Previous studies investigating the relationship between physical work demands and musculoskeletal disorders are mainly based on self-reported exposures and lack a prospective design. The aim of this paper is to describe the background and methods and discuss challenges for a field study examining physical demands in construction and health care work and their prospective associations with musculoskeletal disorders, work ability and sickness absence.
Scandinavian Journal of Work, Environment & Health, 2014
A longitudinal study on risk factors for neck and shoulder pain among young adults in the transit... more A longitudinal study on risk factors for neck and shoulder pain among young adults in the transition from technical school to working life by Hanvold TN, Waersted M, Mengshoel AM, Bjertness E, Twisk J, Veiersted KB
Scandinavian Journal of Work, Environment & Health, 2013
The results indicate that sustained trapezius muscle activity with periods of more than 4 minutes... more The results indicate that sustained trapezius muscle activity with periods of more than 4 minutes duration for more than half of the working day, increases the rate of neck and shoulder pain in a 2.5-year period. This implicates the importance of reducing the lengths of periods with sustained muscle activity at work. Hanvold TN, Waersted M, Mengshoel AM, Bjertness E, Stigum H, Twisk J, Veiersted KB. The effect of work-related sustained trapezius muscle activity on the development of neck and shoulder pain among young adults. Scand J Work Environ Health -online first.
Journal of Occupational and Environmental Medicine, 2013
To examine the effect of sex and socioeconomic position (SEP) on individuals' perceptions of pain... more To examine the effect of sex and socioeconomic position (SEP) on individuals' perceptions of pain and its work-relatedness. Methods: We compared self-reported pain in neck-shoulder or arm with clinical diagnoses and workers' judgments of work-relatedness with physicians' assessments based on specific criteria, between sexes and high-and low-SEP participants in the Oslo Health Study (n = 217). Results: Clinical diagnoses were more frequent in low-SEP subjects than high-SEP subjects with pain and generally higher in women than in men. Pain attributed to work was more frequently assessed as work-related by the physicians in low-SEP subjects than high-SEP subjects and in men than in women of low SEP. Conclusions: The threshold for reporting pain seemed higher in low-SEP subjects and among women. Physicians were more likely to agree with low-SEP workers about work-relatedness.
Journal of Adolescent Health, 2010
Purpose: The aim of this prospective study was to relate the prevalence of neck, shoulder, and up... more Purpose: The aim of this prospective study was to relate the prevalence of neck, shoulder, and upper back pain to occupational and individual risk factors among a population of technical school students in their transition from school to working life. In addition, we wanted to assess the changes in pain prevalence during follow-up. Methods: A cohort consisting of 173 technical school students was followed up during a 3-year period, from their last year of school through their first years of working life. Data on self-reported neck, shoulder, and upper back pain and factors such as mechanical exposure, perceived stress, and physical activity in leisure time were collected. Results: A high prevalence of pain in the neck, shoulder, and upper back among the technical school students was found. There were however few students reporting severe pain. Reporting pain at baseline gave over three times higher risk of reporting it at follow-up. A high level of physical activity outside working hours gave a lower risk of reporting neck, shoulder, and upper back pain at follow-up. High and moderate levels of mechanical exposure and high stress level were not found to be risk factors for pain after entering working life. Conclusion: Neck, shoulder, and upper back pain are common among adolescents and may persist into working life. These results may give potential for preventive efforts at a young age. There is still much uncertainty about the factors leading to musculoskeletal pain, and more research is needed on this topic. Ó
International Journal of Industrial Ergonomics, 1997
Body posture and trapezius EMG activity of twelve subjects were evaluated in an experimental VDU-... more Body posture and trapezius EMG activity of twelve subjects were evaluated in an experimental VDU-based work task and a paper-based task with the same work content. Work pace was faster with maintained quality (number of errors not significantly changed) in the VDU version of the work task. The seated posture was more upright. A low-level static EMG activity component was present most of the work time in both versions of the task. The EMG activity level was similar or decreased in the VDU version. Both the posture and the EMG activity showed significantly less variation in the VDU version. It is hypothesized that the decreased variation of physiological load patterns (posture and EMG), when a work task is transformed from paper-based to VDU-based, can be a risk factor for musculoskeletal complaints.
European Journal of Applied Physiology and Occupational Physiology, 1996
Activity of single motor units in relation to surface electromyography (EMG) was studied in 11 su... more Activity of single motor units in relation to surface electromyography (EMG) was studied in 11 subjects in attention-demanding work tasks with minimal requirement of movement. In 53 verified firing periods, single motor units fired continuously from 30 s to 10 min (duration of the experiment work task) with a stable median firing rate in the range of 8–13 Hz. When