Can a metric combining arm elevation and trapezius muscle activity predict neck/shoulder pain? A prospective cohort study in construction and healthcare.

OBJECTIVE: To determine whether a composite metric of arm elevation and trapezius activity (i.e. neck/shoulder load) is more strongly associated with the 2-year course of neck and shoulder pain intensity (NSPi) among construction and healthcare workers than each exposure separately. METHODS: Dominant arm elevation and upper trapezius muscle activity were estimated in construction and healthcare employees (n = 118) at baseline, using accelerometry and normalized surface electromyography (%MVE), respectively. At baseline and every 6 months for 2 years, workers reported NSPi (score 0-3). Compositions of working time were determined for arm elevation (< 30°; 30-60°; > 60°), trapezius activity (< 0.5%; 0.5-7.0%; > 7.0%MVE), and a composite metric "neck/shoulder load" (restitution, low, medium, and high load). Associations between each of these three compositions and the 2-year course of NSPi were determined using linear mixed models. RESULTS: Associations between exposure compositions and the course of NSPi were all weak and in general uncertain. Time spent in 0.5-7.0%MVE showed the largest and most certain association with changes in NSPi during follow-up (ß = - 0.13; p = 0.037; corresponding to a -0.01 change in NPSi every 6 months). Among pain-free workers at baseline, medium (ß = - 0.23; p = 0.039) and high (ß = 0.15; p = 0.031) neck/shoulder load contributed the most to explaining changes in NSPi. CONCLUSION: The composite metric of neck/shoulder load did not show a stronger association with the course of NSPi than arm elevation or trapezius activity alone in the entire population, while some indications of a stronger association were found among those who were pain-free at baseline.

Associations of objectively measured total duration and maximum bout length of standing at work with lower-extremity pain intensity: a 2-year follow-up of construction and healthcare workers.

BACKGROUND: Musculoskeletal disorders are among the major reasons for years lived with disability. Approximately one third of the European working population report lower-extremity discomfort and many attribute these discomforts to work-related factors. Employees in the healthcare and construction sectors reports high levels of lower-extremity pain and commonly relate the pain to their profession. These workers spend a large part of their workday standing. Periods of prolonged standing is suggested to increase lower-extremity symptoms, but this cannot be concluded on, since limited evidence is available from longitudinal studies using objective measures. This study aimed to determine possible associations between objectively measured total duration and maximum bout length of static- and dynamic standing at work and lower-extremity pain intensity (LEPi) among Norwegian construction- and healthcare workers. METHODS: One-hundred and twenty-three construction and healthcare workers wore two accelerometers for up to four consecutive days, to establish standing behavior at baseline. The participants reported LEPi (Likert scale 0-9) for the preceding 4 weeks at baseline and after 6, 12, 18, and 24 months. We investigated associations between standing at work and average and change in LEPi using linear mixed models with significance level p ≤ 0.05. RESULTS: Total duration of static- and dynamic standing showed weak associations with average LEPi, for the total sample and for construction workers. Maximum bout of static- and dynamic standing was associated with average LEPi in construction workers, but not in healthcare workers. Furthermore, we found no associations between standing and change in LEPi over the 2-year follow-up in any of our analyses. CONCLUSIONS: This study indicate that objectively measured standing is associated with average LEPi over 2-years follow-up in construction workers, and that maximal bout of standing have a stronger association to LEPi than total duration. For every 10 min added to the maximal length of continuous standing during an average workday, we found approximately one unit increase in pain on a 0-9 scale. The lack of significant findings in analyses on healthcare workers suggest that the association between standing and LEPi depend on work-tasks, gender and/or other sector-specific factors.

Work above shoulder level and shoulder complaints: a systematic review.

OBJECTIVE: To investigate the association and the exposure-response relationship between work above shoulder height and shoulder pain or disorders. METHODS: A systematic search was performed in Medline, Embase, and Health and Safety Science Abstracts. Included were articles with prospective cohort, case-control, cross-sectional, or intervention study designs. Quality assessment was based on an evaluation scheme adjusted to study design and normalized to 100%. The cut-off for sufficient quality to include articles was above 40% and cut-off for high-quality articles was above 50% of maximal score. The level of strength of evidence for an association between exposure and effect was assessed according to the GRADE guidelines. RESULTS: Thirty-four articles were included. Articles that document large effects (higher risk estimates; OR ≥ 2) have higher quality score, include analyses of severe arm elevation, more often use clinical outcome, and report an exposure-response relationship compared to studies reporting lower risk estimates. The studies that reported large effects were all significant. An exposure-response relationship was found in many high-quality studies when relating exposure intensity of arm elevation (level of arm elevation, amplitude) as well as duration of arm elevation, especially > 90°. CONCLUSION: We conclude on a limited evidence for an association between arm elevation at work and shoulder disorders. Severe arm elevation with elbows above shoulder level (i.e., > 90°) shows a moderate evidence for an association with shoulder disorders.

Associations of objectively measured forward bending at work with low-back pain intensity: a 2-year follow-up of construction and healthcare workers.

OBJECTIVES: This study aimed to determine possible associations between objectively measured forward bending at work (FBW) and low-back pain intensity (LBPi) among Norwegian construction and healthcare workers. METHODS: One-hundred and twenty-five workers wore two accelerometers for 3-4 consecutive days, during work and leisure to establish duration of ≥30° and ≥60° forward bending. The participating workers reported LBPi (0-3) at the time of objective measurements and after 6, 12, 18 and 24 months. We investigated associations using linear mixed models with significance level p≤0.05 and presented results per 100 min. RESULTS: The duration of ≥30° and ≥60° FBW was not associated with average LBPi during follow-up, neither for the total sample nor stratified on work sector. Furthermore, analyses on all workers and on construction workers only found no significant association between ≥30° or ≥60° FBW and change in LBPi over the 2-year follow-up. For healthcare workers we found a consistent significant association between the duration of ≥30° FBW at baseline and the change in LBPi during follow-up, but this was not found for ≥60° FBW. CONCLUSIONS: This study suggests that objectively measured duration of FBW in minutes is not associated with average levels of, or change in LBPi in construction workers over a 2-year period. In healthcare workers, exposure to ≥30° FBW was associated with change in LBPi, while we did not find this for ≥60° FBW. Results may indicate that the associations between FWB and LBP vary depending on type of work tasks, gender or sector-specific factors.

Physical capacity, occupational physical demands, and relative physical strain of older employees in construction and healthcare.

PURPOSE: To assess age-related differences in physical capacity, occupational physical demands, and relative physical strain at a group level, and the balance between capacity and demands at an individual level, for construction and healthcare workers. METHODS: Shoulder strength, back strength, and aerobic capacity were assessed among construction (n = 62) and healthcare workers (n = 64). During a full working day, accelerometers estimated upper-arm elevation, trunk flexion, and occupational physical activity as indicators of occupational physical demands. Simultaneously, normalised surface electromyography (%sEMGmax) of the upper trapezius and erector spinae muscles, and normalised electrocardiography (percentage heart rate reserve (%HRR)) estimated relative physical strain. Differences between younger (≤ 44 years) and older (≥ 45 years) workers, as well as the moderating effect of age on the associations between capacity and demands, were analysed per sector. RESULTS: Compared to younger workers, older workers had similar strength and lower aerobic capacity; older construction workers had similar demands while older healthcare workers had higher demands. Compared to younger workers, older employees had unfavourable muscle activity patterns; %HRR had a tendency to be lower for older construction workers and higher for older healthcare workers. Among construction workers, age moderated the associations between shoulder strength and arm elevation (p = 0.021), and between aerobic capacity and occupational physical activity (p = 0.040). Age did not moderate these associations among healthcare workers. CONCLUSIONS: In both sectors, the level of occupational physical demands and the higher relative physical strain in older employees require addressing to promote sustainable work participation among an aging population.

Sleep duration mediates abdominal and lower-extremity pain after night work in nurses.

OBJECTIVES: The aim of this study was to investigate the association between different working shifts (i.e. morning, evening, night shifts) and headache, musculoskeletal and abdominal pain, and the extent to which reduced sleep duration could account for these associations. METHODS: Nurses (N = 679, 649 female, aged 22-53 years) were followed up for a period of 28 consecutive days, responding to a diary about sleep, shift type and pain complaints (measured on a Likert-type scale ranging from 0 to 3). Generalised structural equation modelling mediation analysis (GSEM) was performed to test whether shift type was associated with higher incidence or higher intensity of pain (headache, pain in neck/shoulders/upper back, upper extremity, low back, lower extremity and abdominal pain), and if this effect was mediated by sleep duration (continuous variable), after controlling for age, work and lifestyle factors. RESULTS: Pain scores in lower extremities were decreased following night shifts in general. However, when night shifts were followed by short sleep duration, the risk of pain in the lower extremities and abdominal pain were increased. Headache and pain in the upper extremity were increased after night shifts, but were not associated with sleep duration. Pain in the neck/shoulder/upper back and lower back was not related to shift work. CONCLUSIONS: Among nurses in a three-shift rotating schedule, night shifts increased the risk of pain in several regions, but only pain in the lower extremities and abdomen was related to reduced sleep duration.

Multisite musculoskeletal pain among young technical school students entering working life.

BACKGROUND: 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. METHODS: 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). RESULTS: 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. Increased mechanical workload and quantitative demands and low socioeconomic status were associated with increased number of musculoskeletal pain sites among women, while tobacco use was found as a risk factor among young men. Increased perceived muscle tension was the only factor significantly associated with increased number of pain sites in both genders. CONCLUSION: The current study supports earlier findings and show that pain from multiple body sites are frequent also among young workers. The identification of gender specific risk factors in our study is important and may facilitate practical prevention and future research.

Low back pain and physical activity--A 6.5 year follow-up among young adults in their transition from school to working life.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Musculoskeletal health and work ability in physically demanding occupations: study protocol for a prospective field study on construction and health care workers.

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. METHODS AND DESIGN: This protocol describes a prospective cohort study on 1200 construction and health care workers. Participants will answer a baseline questionnaire concerning musculoskeletal complaints, general health, psychosocial and organizational factors at work, work demands, work ability and physical activity during leisure. A shorter questionnaire will be answered every 6th months for a total of two years, together with continuous sickness absence monitoring during this period. Analysis will prospectively consider associations between self-reported physical demands and musculoskeletal disorders, work ability and sickness absence. To obtain objective data on physical exposures, technical measurements will be collected from two subgroups of N = 300 (Group A) and N = 160 (Group B) during work and leisure. Both group A and B will be given a physical health examination, be tested for physical capacity and physical activity will be measured for four days. Additionally, muscle activity, ground reaction force, body positions and physical activity will be examined during one workday for Group B. Analysis of associations between objectively measured exposure data and the outcomes described above will be done separately for these subpopulations. DISCUSSION: The field study will at baseline produce objectively measured data on physical demands in the construction and health care occupations. In combination with clinical measurements and questionnaire data during follow-up, this will provide a solid foundation to prospectively investigate relationships between physical demands at work and development of musculoskeletal disorders, work ability and sickness absence.

Frequency of breaks, amount of muscular rest, and sustained muscle activity related to neck pain in a pooled dataset.

BACKGROUND: Neck pain remains a persistent challenge in modern society and is frequently encountered across a wide range of occupations, particularly those involving repetitive and monotonous tasks. It might be expected that patterns of trapezius muscle activity at work, characterized by few breaks and prolonged periods of sustained muscle activity, are linked to neck pain. However, previous cross-sectional studies have generally failed to establish a definitive association. While some longitudinal studies have suggested that extended periods of heightened muscle activity could be a risk factor for neck pain, these findings often relied on limited participant numbers or specific professional groups. This study aimed to investigate the relationship between trapezius muscle activity and neck pain by pooling data from seven Scandinavian research institutes encompassing a diverse range of occupational backgrounds. METHODS: Electromyographic (EMG) data for the upper trapezius muscle, collected during working hours, were coupled with questionnaire responses pertaining to neck pain, individual characteristics, and potential confounding variables for a total of 731 subjects. Additionally, longitudinal data from 258 subjects were available. The various EMG datasets were consolidated into a standardized format, and efforts were made to harmonize inquiries about neck pain. Regression analyses, adjusting for sex and height, were conducted to explore the associations between muscle activity variables and neck pain. An exposure index was devised to quantify the cumulative neck load experienced during working hours and to differentiate between various occupational categories. RESULTS: The cross-sectional data displayed a distinct pattern characterized by positive associations for brief periods of sustained muscle activity (SUMA) and negative associations for prolonged SUMA-periods and neck pain. The longitudinal data exhibited a contrasting trend, although it was not as pronounced as the cross-sectional findings. When employing the exposure index, notable differences in cumulative muscle load emerged among occupational groups, and positive associations with longitudinal neck pain were identified. DISCUSSION: The results suggest that individuals with neck pain experience higher cumulative workloads and extended periods of muscle activity over the long term. In the short term, they appear to compensate by taking frequent short breaks, resulting in a lower cumulative workload. Regardless of their occupation, it is crucial to distribute work breaks throughout the workday to ensure that the cumulative load remains manageable.

Defensive Functioning Moderates the Effects of Nondirective Meditation.

We have recently found that nondirective meditation facilitates stress reduction. This supplementary study investigated whether defensive functioning would moderate these beneficial effects. We explored the occurrence of defense mechanisms and the impact of defensive functioning on the outcome of companies' stress management programs regarding worries nervousness, mental distress, sleep problems, and muscle pain. The sample was a population of active, working professionals recruited from Norwegian companies (n = 105). The intervention group obtained significant benefits on all outcome measures, but there were no effects in the control group. We analyzed defensive functioning with the self-report questionnaire, Life Style Index, at four time points. The healthy adults who participated had a low level of defense scores at the outset. There was a significant reduction in the level of defenses in both groups over the study period, 6 months. Defensive functioning significantly moderated the change of the outcome measures from baseline to follow-up in the intervention group, but not in the control group.

Do intensity of pain alone or combined with pain duration best reflect clinical signs in the neck, shoulder and upper limb?

OBJECTIVES: It is important to validate self-reported musculoskeletal pain used in epidemiological studies for evaluation of pain outcome measures. The main objective of this paper was to assess the association between self-reported neck/shoulder/upper limb pain and clinical signs of disorders in the region, especially by comparing a measure that only used pain intensity with a measure that combined pain intensity and pain duration. METHODS: Four hundred and twenty technical school students of both genders were included with a median age of 17 years (16-28). The students stated the pain in four intensity grades and the pain duration in four period lengths within the preceding four weeks period. A pain severity index was calculated by multiplying the pain intensity (0-3) and the duration (1-4). A clinical examination was performed within a week after completing the form. The associations were evaluated by agreement, correlation and symmetric strength of association (contingency). RESULTS: The study found low correlation and low positive agreement for neck/shoulder and upper limb pain related to clinical signs of disorders in the region. However, the relationship showed high negative agreement and high contingency. The negative agreement increased for the neck/shoulder region with higher cut-off points for dichotomization, but not for the upper limb region. The index combining reports of pain intensity with pain duration, do not improve agreement, correlation or contingency with clinical signs compared to use of pain intensity alone. CONCLUSIONS: This study showed an association between self-reported neck/shoulder/upper limb pain intensity and clinical signs of musculoskeletal disorders of the region. An index combining pain intensity and duration (Pain Severity Index) did not increase this association. From the results we suggest using pain intensity reports alone and if dichotomizing is wanted, choosing a cut-off point at high pain levels, especially for neck and shoulder pain.

Computer work and musculoskeletal disorders of the neck and upper extremity: a systematic review.

BACKGROUND: This review examines the evidence for an association between computer work and neck and upper extremity disorders (except carpal tunnel syndrome). METHODS: A systematic critical review of studies of computer work and musculoskeletal disorders verified by a physical examination was performed. RESULTS: A total of 22 studies (26 articles) fulfilled the inclusion criteria. Results show limited evidence for a causal relationship between computer work per se, computer mouse and keyboard time related to a diagnosis of wrist tendonitis, and for an association between computer mouse time and forearm disorders. Limited evidence was also found for a causal relationship between computer work per se and computer mouse time related to tension neck syndrome, but the evidence for keyboard time was insufficient. Insufficient evidence was found for an association between other musculoskeletal diagnoses of the neck and upper extremities, including shoulder tendonitis and epicondylitis, and any aspect of computer work. CONCLUSIONS: There is limited epidemiological evidence for an association between aspects of computer work and some of the clinical diagnoses studied. None of the evidence was considered as moderate or strong and there is a need for more and better documentation.

Pain complaints after consecutive nights and quick returns in Norwegian nurses working three-shift rotation: an observational study.

OBJECTIVES: To determine whether nurses working consecutive night shifts, or short transitions between shifts (quick returns (QRs)), yielded higher risk for pain complaints when compared with regular morning shifts. Sleep duration was tested as a potential mediator. DESIGN: Observational diary study. SETTING: Random hospitals. PARTICIPANTS: Nurses with three-shift rotation (morning, evening and night), n=679, 22-63 years old. OUTCOMES MEASURES: Daily ratings of working hours, sleep and subjective pain complaints in six anatomical regions (head, neck/shoulder/upper back, upper extremity, low back, lower extremity and abdomen) for 28 days. In addition, we assessed demographics, habitual sleep and pain complaints, work and lifestyle factors. It was tested (1) whether the risk for pain complaints was higher after workday 3 versus after workday 2, and whether the difference was larger for consecutive night shifts versus consecutive morning shifts, and (2) whether the risk for pain complaints was higher after QRs versus after two morning shifts. Risk for pain complaints refers to combined increased risk for any pain and risk for increased intensity. RESULTS: Adjusted analyses showed no shift type by workday interaction for pain complaints in the neck/shoulder/upper back, upper extremities, low back, lower extremities or abdomen. For headache, a strong trend indicated that the risk was higher on workday 3 compared with workday 2 for night shifts (OR 1.13, 95% CI 0.99 to 1.28). The risk was lowered if sleep duration was taken into account (OR 0.37, 95% CI 0.17 to 0.81). No conclusive support was found for the risk for pain complaints being higher after QRs, compared with after morning shifts. CONCLUSIONS: For five of six pain complaints, the hypotheses were not supported by the current data. For headache, we found potential support for a sleep-relieving effect on headache after working several nights in a row. Pain complaints were not instigated or exacerbated by an evening-to-morning transition between shifts.

Self-reported versus expert-assessed work-relatedness of pain in the neck, shoulder, and arm.

OBJECTIVES: The aim of this study was to compare self-reported work-relatedness of neck-shoulder and arm pain with experts' assessments based on specific criteria. METHODS: A sample of 217 employed participants in the Oslo Health Study 2000-2001, aged 30, 40, and 45 years, who reported neck-shoulder or arm pain in the past month, underwent a health examination. A criteria document for evaluating the work-relatedness of upper-extremity musculoskeletal disorders was used to -establish clinical diagnoses and assess the work-relatedness of pain with respect to the subject's present job. We measured agreement between the participants and experts on whether pain was related to work as observed agreement, positive and negative specific agreement, and kappa. RESULTS: A major proportion of the cases were assessed as work-related, somewhat more frequently by self-report than when assessed by experts (80% versus 65% for neck-shoulder pain, and 78% versus 72% for arm pain, respectively). However, there was considerable disagreement as to which cases were work-related. The experts disagreed more frequently in cases that were reported as non-work-related (particularly for neck-shoulder pain and cases reported by men). Positive specific agreement was fairly high (76-85% in the total population), while negative specific agreement was lower (37-51%). Kappa values were also low (0.16-0.34). CONCLUSIONS: Compared with expert assessment, self-reporting did not seem to particularly exaggerate work-relatedness. Nevertheless, there was considerable disagreement, especially on cases assessed as non-work--related. However, agreement will depend on the case definitions and the criteria for work-relatedness used both by the participants and the experts.

Occupational Safety and Health Among Young Workers in the Nordic Countries: A Systematic Literature Review.

This review aimed to identify risk factors for occupational accidents and illnesses among young workers in the Nordic countries and to attain knowledge on specific vulnerable groups within the young working force that may need special attention. We conducted a systematic review from 1994 to 2014 using five online databases. Of the 12,528 retrieved articles, 54 met the review criteria and were quality assessed, in which data were extracted focusing on identifying occupational safety, health risk factors, and vulnerable groups among the young workers. The review shows that mechanical factors such as heavy lifting, psychosocial factors such as low control over work pace, and organizational factors such as safety climate are all associated with increased injury risk for young Nordic workers. Results show that exposures to chemical substances were associated with skin reactions, e.g., hand eczema. Heavy lifting and awkward postures were risk factors for low back pain, and high job demands were risk factors for mental health outcomes. The review identified young unskilled workers including school drop-out workers as particularly vulnerable groups when it comes to occupational accidents. In addition, apprentices and young skilled workers were found to be vulnerable to work-related illnesses. It is essential to avoid stereotyping young Nordic workers into one group using only age as a factor, as young workers are a heterogeneous group and their vulnerabilities to occupational safety and health risks are contextual. Politicians, researchers, and practitioners should account for this complexity in the education, training and organization of work, and workplace health and safety culture.

Simple descriptive missing data indicators in longitudinal studies with attrition, intermittent missing data and a high number of follow-ups.

OBJECTIVE: Missing data in longitudinal studies may constitute a source of bias. We suggest three simple missing data indicators for the initial phase of getting an overview of the missingness pattern in a dataset with a high number of follow-ups. Possible use of the indicators is exemplified in two datasets allowing wave nonresponse; a Norwegian dataset of 420 subjects examined at 21 occasions during 6.5 years and a Dutch dataset of 350 subjects with ten repeated measurements over a period of 35 years. RESULTS: The indicators Last response (the timing of last response), Retention (the number of responded follow-ups), and Dispersion (the evenness of the distribution of responses) are introduced. The proposed indicators reveal different aspects of the missing data pattern, and may give the researcher a better insight into the pattern of missingness in a study with several follow-ups, as a starting point for analyzing possible bias. Although the indicators are positively correlated to each other, potential predictors of missingness can have a different relationship with different indicators leading to a better understanding of the missing data mechanism in longitudinal studies. These indictors may be useful descriptive tools when starting to look into a longitudinal dataset with many follow-ups.

Heavy Physical Work: Cardiovascular Load in Male Construction Workers.

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 V̇O(2max), but not with work ability, musculoskeletal pain or subjective general health.

Work with prolonged arm elevation as a risk factor for shoulder pain: a longitudinal study among young adults.

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 (2006/7-2009). 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.

A longitudinal study on risk factors for neck and shoulder pain among young adults in the transition from technical school to working life.

OBJECTIVES: The study examined the course of neck and shoulder pain among a cohort of technical school students entering working life. We also aimed to identify work-related and individual risk factors for neck and shoulder pain during this transition period. METHODS: The study was designed as a prospective cohort study following 420 technical school students (167 student hairdressers, 118 student electricians, and 135 media/design students) from school, through their apprenticeship and into working life. Every 4 (th)month over a 6.5 year period (2002-2009), the participant`s neck and shoulder pain for the preceding four weeks was assessed. Mechanical and psychosocial workplace factors as well as individual factors were evaluated at baseline and/or during the follow-up period. Data were analyzed by generalized estimating equations (GEE). RESULTS: We found a significant increase in neck and shoulder pain over time in the transition from technical school to working life. High mechanical workload was associated with neck and shoulder pain among women, while a high level of shoulder muscle endurance capacity was associated with lower rates of neck and shoulder pain among men. Perceived muscle tension and ethnicity were the most consistent predictors for neck and shoulder pain, found among both women and men. CONCLUSION: Increased neck and shoulder pain was found in the transition from technical school to working life, and both work-related and individual factors were associated with pain development.