Work-related musculoskeletal disorders - exposure assessment and gender aspects

Work-related musculoskeletal disorders are widespread, and are, for unclear reasons, more common among females than in males. Several risk factors have been described; constrained and awkward postures, repetitive and/or force demanding motions, and lack of recovery. The exposure to such risk factors was systematically assessed in 116 male and 206 female fish-processing industry workers. Large differences were shown, females to a much higher extent performed repetitive work with constrained neck postures, while males had heavier, but more varied work tasks. Surface electromyography (EMG) was evaluated as a measurement method of muscular activity. An important aspect is time for recovery of muscle fibres, especially in work tasks that demand low level, long duration activity. Muscle fibres are recruited according to a predefined order, some them, probably, being active whenever the muscle is used. To assess recovery time in these, a method that quantifies resting time of the entire muscles is needed. Such a method, 'muscular rest', was further developed and validated. It discriminated well between workers in occupations with high and low prevalence of neck/shoulder myalgia. EMG is, moreover, extensively used to assess the level of muscular activity during work. Large differences have been shown between individuals that perform the same work task, which could be due to differences in strength or working technique, or to a measurement error. The precision of the method has been poorly known. Six females repeated three different work tasks at three different occasions. For m.trapezius, the variation between days (within individual) was small, 8%. For the forearm extensors, it was somewhat larger, 33%, probably because of less adequate normalisation. To study the impact of gender on the development of neck and upper limb disorders, 105 males and 172 females with identical repetitive and force demanding work tasks were examined. The prevalence of disorders was much higher among the females. Further, the physical exposure was quantified, separately for the genders, by EMG, as well as by inclinometry and goniometry for working postures and movements. When normalising to a maximal exertion, a significant difference was shown, with higher exposures for females. The relative peak load was 50% higher for m.trapezius, and 44% higher for the forearm extensors. Further, females had 45% less muscular rest in the forearm extensors, and 40% higher wrist flexion/extension velocity on the right side. It is likely that a substantial share of the excess morbidity among females can be explained by higher physical exposure at work

The importance of work organization on workload and musculoskeletal health - Grocery store work as a model.

We have evaluated the consequences of work organization on musculoskeletal health. Using a postal questionnaire, answered by 1600 female grocery store workers, their main work tasks were identified and four work groups were defined (cashier, picking, and delicatessen work, and a mixed group, who performed a mix of these tasks). The crude odds ratios (ORs) for neck/shoulder complaints were 1.5 (95% CI 1.0-2.2), 1.1 (0.7-1.5) and 1.6 (1.1-2.3), respectively, compared to mixed work. Adjusting for individual and psychosocial factors had no effect on these ORs. For elbows/hands, no significant differences were found. Technical measurements of the workload showed large differences between the work groups. Picking work was the most strenuous, while cashier work showed low loads. Quantitative measures of variation revealed for mixed work high between minutes variation and the highest between/within minutes variation. Combining work tasks with different physical exposure levels increases the variation and may reduce the risk of musculoskeletal complaints

Population-based consultation patterns in patients with shoulder pain diagnoses

Background: To assess the annual consultation prevalence and new onset consultation rate for doctor-diagnosed shoulder pain conditions. Methods: We identified all residents in the southernmost county in Sweden who received a shoulder pain diagnosis during 2006 (ICD-10 code M75). In subjects who did not consult due to such disorders during 2004 and 2005, we estimated the new onset consultation rate. The distribution of specific shoulder conditions and the length of the period of repeated consultation were calculated. Results: Annual consultation prevalence was 103/10 000 women and 98/10 000 men. New onset consultation rate was 80/10 000 women (peak in age 50-59 at 129/10 000) and 74/10 000 men (peak in age 60-69 at 116/10 000). About one fifth of both genders continued to consult more than three months after initial presentation, but only a few percent beyond two years. Rotator cuff - and impingement syndromes were the most frequent diagnoses. Conclusion: The annual consultation prevalence for shoulder pain conditions (1%) was similar in women and men, and about two thirds of patients consulted a doctor only once. Impingement and rotator cuff syndromes were the most frequent diagnoses

Cross-sectional associations between occupational factors and musculoskeletal pain in women teachers, nurses and sonographers

A. Technical measurements of the physical workload. (DOCX 18 kb