Aims: To determine quantitative exposure-response relations between work with highly elevated arms and supraspinatus tendinitis, shoulder pain with disability, and shoulder pain without disability. Methods: A cross sectional study was conducted in a historical cohort of 1886 males from three occupational groups. Exposure measurements were performed for four consecutive working days in a random sample of 72 currently employed subjects. Individual work histories were obtained by questionnaire and register data. Health status was ascertained by physical examination blinded towards exposure and symptoms. Data were analysed by generalised estimating equation and multiple logistic regression with adjustment for potential confounders. Results: For current upper arm elevation above 90˚, a duration increment of 1% of the daily working hours was associated with odds ratios of 1.23 (95% CI 1.10 to 1.39) for supraspinatus tendinitis, 1.16 (95% CI 1.08 to 1.24) for shoulder pain with disability, and 1.08 (95% CI 1.04 to 1.13) for shoulder pain without disability. The outcomes were not related to duration of employment in one of the three trades. Conclusions: Quantitative exposure-response relations were established between current work with highly elevated arms and clinically verified shoulder disorders. Substantial long term cumulative effects were not shown. A potential for primary prevention was revealed. Shoulder disorders have considerable impact on sickness absence, 1 utilisation of primary 2 and secondary 3 4 health services, and premature withdrawal from the labour market.5 Several occupational exposures have been associated with shoulder complaints and disorders; these include work with elevated arms, monotonous repetitive work, and forceful exertions.6 7 However, most epidemiological investigations into the work relatedness of shoulder disorders suffer from methodological limitations, in particular concerning exposure assessment and verification of disorders.8 The present lack of knowledge hampers the development of guidelines and regulations to prevent work related shoulder disorders. 9Work with elevated arms has been hypothesised to cause degenerative changes in the rotator cuff tendons 10 and thus predispose to tears. It is unclear how high the arms must be elevated and for how long a time before the harmful effects occur. Existing evidence points to elevation angles above 60˚, but the majority of studies cannot separate effects of postural load and monotonous repetitive work.6 Few studies have focused on elevation angles above 90˚, 11-13 and the literature is scarce on the effects of varied patterns of arm elevation. 14-16We aimed to establish quantitative exposure-response relations between work with highly elevated arms and shoulder disorders. The study was based on direct measurements of upper arm elevation, register based data on occupational histories, and physical examinations blinded to exposure and symptoms. METHODS PopulationWe conducted a cross sectional study in a historical cohort of male machinists...

ObjectivesThe primary aim was to examine exposureresponse relationships between cumulative occupational shoulder exposures and surgery for subacromial impingement syndrome (SIS), and to compare sexspecific exposure-response relationships. The secondary aim was to examine the time window of relevant exposures. Methods We conducted a nationwide register study of all persons born in Denmark (1933Denmark ( -1977, who had at least 5 years of full-time employment. In the follow-up period (2003)(2004)(2005)(2006)(2007)(2008), we identified first-time events of surgery for SIS. Cumulative exposure estimates for a 10-year exposure time window with a 1-year lag time were obtained by linking occupational codes with a job exposure matrix. The exposure estimates were expressed as, for example, arm-elevation-years in accordance with the pack-year concept of tobacco consumption. We used a multivariable logistic regression technique equivalent to discrete survival analysis. Results The adjusted OR (OR adj ) increased to a maximum of 2.1 for arm-elevation-years, repetition-years and force-years, and to 1.5 for hand-arm-vibration-years. Sex-specific exposure-response relationships were similar for men and women, when assessed using a relative risk scale. The OR adj increased gradually with the number of years contributing to the cumulative exposure estimates. The excess fraction was 24%. Conclusions Cumulative occupational shoulder exposures carried an increase in risk of surgery for SIS with similar exposure-response curves for men and women. The risk of surgery for SIS increased gradually, when the period of exposure assessment was extended. In the general working population, a substantial fraction of all first-time operations for SIS could be related to occupational exposures.

The impact of occupational biomechanical shoulder exposures on risk of surgery for subacromial impingement syndrome (SIS) is unknown. Shoulder load increased the risk of surgery for SIS. Neck-shoulder complaints combined with high shoulder load conveyed the highest risk.Affiliation:

Background: The physical and psychosocial work environment is expected to modify recovery from shoulder disorders, but knowledge is limited. Methods: In a follow up study of musculoskeletal disorders in industrial and service workers, 113 employees were identified with a history of shoulder pain combined with clinical signs of shoulder tendonitis. The workers had yearly reexaminations up to three times. Quantitative estimates of duration, repetitiveness, and forcefulness of current tasks were obtained from video recordings. Perception of job demands, decision latitude, and social support was recorded by a job content questionnaire. Recovery of shoulder tendonitis was analysed by Kaplan-Meier survival technique and by logistic regression on exposure variables and individual characteristics in models, allowing for time varying exposures. Results: Some 50% of workers recovered within 10 months (95% CI 6 to 14 months). Higher age was strongly related to slow recovery, while physical job exposures were not. Perception of demands, control, and social support at the time when the shoulder disorder was diagnosed, were associated with delayed recovery, but these psychosocial factors did not predict slow recovery in incident cases identified during follow up. Conclusion: The median duration of shoulder tendonitis in a cross sectional sample of industrial and service workers was in the order of 10 months. This estimate is most likely biased towards too high a value. Recovery was strongly reduced in higher age. Physical workplace exposures and perceived psychosocial job characteristics during the period preceding diagnosis seem not to be important prognostic factors.

Background: Evidence for effective interventions to prevent long-term sequelae after concussion is sparse. This study aimed to test the efficacy of Get going After concussIoN (GAIN), an interdisciplinary, individuallytailored intervention of 8 weeks duration based on gradual return to activities and principles from cognitive behavioural therapy. Methods: We conducted an open-label, parallel-group randomised trial in a hospital setting in Central Denmark Region. Participants were 15À30-year-old patients with high levels of post-concussion symptoms (PCS) 2À6 months post-concussion (i.e., a score 20 on the Rivermead Post-concussion Symptoms Questionnaire (RPQ)). They were randomly assigned (1:1) to either enhanced usual care (EUC) or GAIN+EUC. Masking of participants and therapists was not possible. The primary outcome was change in RPQ-score from baseline to 3-month FU. All analyses were done on an intention-to-treat basis using linear mixed-effects models. This trial is registered with ClinicalTrials.gov, number NCT02337101. Findings: Between March 1, 2015, and September 1, 2017, we included 112 patients. Patients allocated to GAIN+EUC (n=57) reported a significantly larger reduction of PCS than patients allocated to EUC (n=55) with a mean adjusted difference in improvement of 7¢6 points (95% confidence interval (CI) 2¢0À13¢1, p=0¢008), Cohen's d=0¢5 (95% CI 0¢1À0¢9). Number needed to treat for prevention of one additional patient with RPQ 20 at 3-month FU was 3¢6 (95% CI 2¢2À11¢3). No adverse events were observed. Interpretation: Compared with EUC, GAIN+EUC was associated with a larger reduction of post-concussion symptoms at 3-month FU. Funding: Central Denmark Region and the foundation "Public Health in Central Denmark Region-a collaboration between municipalities and the region".

We found indications of safe exposure intensities for repetition. Any intensities of force and upper arm elevation >90° above minimal implied an increased risk across 10-year exposure time windows. No independent associations were found for HAV.

Objective. To investigate the risk of total hip replacement (THR) due to primary osteoarthritis in relation to cumulative occupational mechanical exposures and lifestyle factors. Methods. Using register information, we identified first-time THR cases within the Danish working population in 2005-2006. For each case, 2 age-and sex-matched controls were drawn. Persons within 2,500 randomly selected case-control sets received a questionnaire about job history, weight at age 25 years, present weight and height, smoking, and sports activities at age 25 years. The job history was combined with a job exposure matrix. Cumulative exposure estimates were expressed according to the pack-year concept of smoking (e.g., cumulative lifting was expressed as ton-years). We used conditional logistic regression for statistical analyses.

Objective. To determine whether work performed with the arms in a highly elevated position is associated with alterations in the rotator cuff tendons as assessed by magnetic resonance imaging (MRI).Methods. A cross-sectional study was performed in a historical cohort of male machinists, car mechanics, and house painters. The participants were righthanded, ages 40-50 years, and had been employed in their trades for not less than 10 years. Seventy-one percent of invited subjects participated (136 of 192). Lifetime upper arm elevation was assessed by direct measurements combined with individual work histories obtained by questionnaire and from registry data. Supraspinatus tendinopathy was evidenced by MRI signal intensity changes and morphologic alterations. Infraspinatus and subscapularis tendinopathy were also assessed. Additional outcomes were acromioclavicular joint degeneration and humeral head cysts. The MRI findings were evaluated by radiologists who were blinded to exposure status and symptoms.Results. An exposure-response relationship was found between lifetime upper arm elevation and supraspinatus tendinopathy, with an age-adjusted odds ratio of 1.27 (95% confidence interval 1.02-1.60) for a 5-month increase in the total number of fulltime working months spent with the arm elevated >90 o .Conclusion. Work with the arms in a highly elevated position is associated with MRI-diagnosed alterations in the supraspinatus tendon. By demonstrating the first part of a possible biologic pathway, the study corroborates the work-relatedness of rotator cuff disorders.