Documents upper extremity disorders 103 results

Objectives This study compares questionnaire-assessed exposure data on work postures and movements with direct technical measurements.Methods Inclinometers and goniometers were used to make full workday measurements of 41 office workers and 41 cleaners, stratified for such factors as musculoskeletal complaints. The subjects answered a questionnaire on work postures of the head, back, and upper arms and repeated movements of the arms and hands (3-point scales). The questionnaire had been developed on the basis of a previously validated one. For assessing worktasks and their durations, the subjects kept a 2-week worktask diary. Job exposure was individually calculated by time-weighting the task exposure measurements according to the diary.Results The agreement between the self-assessed and measured postures and movements was low (kappa = 0.06 for the mean within the occupational groups and kappa = 0.27 for the whole group). Cleaners had a higher measured workload than office workers giving the same questionnaire response. Moreover, the subjects with neck-shoulder complaints rated their exposure to movements as higher than those without complaints but with the same measured mechanical exposure. In addition, these subjects also showed a general tendency to rate their postural exposure as higher. The women rated their exposure higher than the men did.Conclusions The questionnaire-assessed exposure data had low validity. For the various response categories the measured exposure depended on occupation. Furthermore, there was a differential misclassification due to musculoskeletal complaints and gender. Thus it seems difficult to construct valid questionnaires on mechanical exposure for establishing generic exposure-response relations in epidemiologic studies, especially cross-sectional ones. Direct technical measurements may be preferable.

The incidence of upper-limb, neck-shoulder, and low-back disorders and their induction times were investigated among new workers in tasks with various physical workloads.New trailer assemblers (N=364) were followed prospectively for 45 months - the workers' health status via medical records and exposure to physical workload factors via job titles, walk-throughs, task descriptions, and some direct measurements. The incidence rate of first sick leave due to such disorders was calculated for different workload groups. The proportion of workers surviving without musculoskeletal disorders was estimated by the Kaplan-Maier product-limit estimator, and the effect of the exposure on the risk of incident disorders was estimated with the Cox proportional hazards model.The highest annual incidences were observed for strenuous tasks, the incidence rate for men being 16.8 per 100 person-years [95% confidence interval (95% CI) 8.0-30.9] for upper-limb disorders in strenuous tasks and 6.1 (95% CI 2.0-14.1) in nonstrenuous tasks and that for women being 32.0 (95% CI 11.7-69.7) and 9.9 (95% CI 0.2-54.9), respectively. The men's risk of contracting an upper-limb or neck-shoulder disorder in strenuous tasks was about threefold [hazard ratio (HR) 3.2 (95% CI 1.1-9.4) for upper-limb disorders and 2.7 (95% CI 0.9-8.1) for neck-shoulder disorders] that of nonstrenuous tasks, whereas workload seemed not to affect low-back disorders. The workers first sought medical advice for their disorders typically some months after employment began.Newly employed workers in hand-intensive tasks have a high risk of upper-limb and neck-shoulder disorders. An etiologic role for activities involving high force demands in upper-limb and neck-shoulder disorders is possible.

The systematic review by Konijnenberg et al (1) in this issue of the Scandinavian Journal of Work Environment & Health deals with conservative treatment methods for the great problem of neck and upper-limb disorders in working populations. Fifteen randomized controlled trials (RCT) or controlled clinical trials (CCT) fulfilled the inclusion criteria of the review. Five of these scored 6/12 or higher according to their internal validity criteria and were considered high-quality studies. In the presence of a wide range of treatments, no treatment modality could be evaluated on the basis of a remarkable number of high-quality studies. There was, however, limited evidence in favor of physiotherapy, exercises, and ergonomic improvements. Repetitive strain injury (RSI) is a loose concept used in this review broadly to encompass a range of disorders from the neck and thoracic spinal area to the fingertip. In principle, outcomes in treatment or intervention studies should be based on symptoms or findings or both independently of the etiologic factors of the disease, and we should avoid concepts that include the assumed etiologic factor. To me, "neck and upper-limb disorders in working populations" would have seemed to be a more appropriate concept, especially since the work-relatedness of the conditions is difficult to assess; in fact it was not even addressed in some of the studies reviewed. Moreover, the requirement of work-relatedness resulted in the exclusion of some potentially high-quality studies (2) that did not have "work-relatedness" as an inclusion criterion, but still probably dealt with a largely similar group of disorders. For instance, in the study of Taimela et al (2), one inclusion criterion was the possession of a permanent job. But if we accept the concept of repetitive strain injury and assume that repetitive movements are one of the major causes of this strain, would not then modification of exposure (or engineering control) be a natural component in a treatment aimed to enhance recovery and prevent recurrence? Many of us would probably say yes, but a look at the tables in the review shows that only very few studies had workplace adjustment as a treatment or as one constituent in the treatment protocol. Another conspicuous feature of this review and also of some other related recent reviews (for an example, see reference 3) is that ergonomic intervention has usually been carried out in the office environment. While there is no doubt that office workers do have work-related musculoskeletal problems, such problems are even more frequent in the construction, transportation, and manufacturing industries and in some branches of the service sector, for example, hospital, kitchen, and cleaning work (4). Hopefully, the target workplaces for future workplace intervention studies will be determined by the size and seriousness of the problems and not only by the feasibility of carrying out an intervention study, such as stationary work in an office environment versus a changing work environment at a construction site, or the marketing of new input devices or computers. The magnitude or the duration of the treatment effects did not deserve much attention in this review, which is understandable since high-quality studies were few in number. However, a look at the high-quality studies shows that a modest reduction in pain was typical, and this effect was no longer present in the later phases of follow-up. Cost-effectiveness aspects were not considered in any of the studies included in this review. The relatively meager results in most studies do not suggest that the treatments were cost-effective in general. Many risk factors contribute to the occurrence of neck and upper-limb disorders among working populations (5, 6, 7). In a multifactorial condition, it is unlikely that a single measure would result in significant relief, something that is suggested by the meager results in several studies accepted for review. With regard to the etiology of most neck and upper-limb disorders, multidisciplinary approaches should have a higher potential. Unfortunately, multidisciplinary rehabilitation had been tried in only one controlled clinical trial, which received a very low score. The authors are correct in being worried about the use of multiple outcomes in intervention studies, the result being a high likelihood that a positive result is obtained by one of the outcomes by chance. Researchers should be more critical in the design of their studies. They should select only the most relevant outcome measures and restrict the outcomes only to them. Most studies relied solely on subjective outcome parameters, since few generally accepted objective methods exist. This is a major scientific problem, especially since blinding subjects for treatment is hardly possible. A major question of treatment policy in relation to neck and upper-limb disorders among working populations is whether the focus should be on treating the individual or his or her environment, especially in the control of workload. Trying to get an answer from workplace intervention studies, especially randomized controlled trials, involves an inherent potential of bias. As it is much easier to randomize individuals into different physical therapies, exercise or other treatment modalities, than it is to randomize workstations to be changed or not, there will always be more randomized controlled trials with treatments directed toward the individual. Therefore, there are greater chances of obtaining positive results from such treatments at the cost of engineering controls. Moreover, the current instability at workplaces, with high turnover rates and frequent reorganizations, makes it increasingly difficult to carry out workplace intervention studies successfully. It is easy to share the authors' worry about the absence of high-quality studies as evidence for the effect of most currently used treatment modalities. As the authors say, there is a higher possibility of bias, for example, an erroneous positive result of a treatment, in a low-quality study than in one of high-quality. This issue was systematically addressed in a review on acupuncture trials involving chronic neck and back pain (8), in which the authors were able to show that the most valid trials tended to have negative results. Konijnenberg and his collaborators' review shows convincingly that the scientific basis for current treatment practices with respect to neck and upper-limb disorders in working populations is limited and based largely on low-quality studies. More high-quality studies are definitely needed. Moreover, research priorities should not be restricted to groups of workers and treatment modalities that are easy to study. Instead, studies should be undertaken on treatment modalities that carry a potential to be efficacious. Worker groups with the highest risk of neck and upper-limb disorders should be the focus. Such studies are often laborious and should therefore be supported by sufficient funding. It is possible that new knowledge from such studies may change our understanding of the efficacy of some treatments and, therefore, create pressure to change current treatment practices. What should the practitioner do now while we are still waiting for the results of such studies? The Panel on Musculoskeletal Disorders established by the National Research Council and the Institute of Medicine concluded in their review that the epidemiologic evidence for upper-extremity disorders supports the important role of physical load factors (7). Based on this evidence, primary and secondary intervention at the workplace, including engineering and administrative controls, was recommended. As there are still few prospective studies on incident neck and upper-limb disorders, it is difficult, on the basis of epidemiologic studies, to estimate the relative potential of these measures in primary versus secondary prevention.

Objectives A longitudinal study was conducted to determine the predictability of personal and occupational factors with respect to the incidence of upper-limb disorders in occupations requiring repetitive work.Conclusions This study considered different sets of risk factors simultaneously with a longitudinal approach, in a population with a high level of occupational exposure. The results indicate that three sets of risk factors independently affect the incidence of upper-limb disorders. In addition to biomechanical constraints, psychosocial and personal factors play a role.

"OBJECTIVES:
The objective of this study was to determine whether there are gender differences in the effect of exposure to work-related physical and psychosocial risk factors on low back, neck, shoulder, or hand-arm symptoms and related sickness absence.
METHODS:
Data of a prospective cohort (study on musculoskeletal disorders, absenteeism stress and health) with a follow-up period of three years were used. Questionnaires were used to assess exposure to risk factors and musculoskeletal symptoms. Sickness absence was registered continuously. Female-to-male gender ratios (GR) were calculated to determine whether there were any differences in the effect. A GR value >1.33 or <0.75 was regarded as relevant.
RESULTS:
Except for the effect of bending the wrist and the neck backwards (GR 1.52-2.55), men generally had a higher risk of symptoms (GR range 0.50-0.68) with equal exposure. For sickness absence, a GR value of >1.33 was found for twisting the upper body, working in uncomfortable postures, twisting the wrist, bending the neck backwards, and coworker and supervisor support (GR range 1.66-2.63). For driving vehicles, hand-arm vibration, squeezing, working above shoulder level or below knee level, reaching, twisting the neck, job demands, and skill discretion, the GR value was <0.75. For job satisfaction, a GR value of 0.50 was found for absence due to back symptoms, while the GR value was 1.78 for sickness absence due to neck, shoulder, or hand-arm symptoms.
CONCLUSIONS:
Although women are expected to be more vulnerable to exposure to work-related risk factors, the results of this study show that, in many cases, men are more vulnerable. This study could not explain the gender difference in musculoskeletal symptoms among workers."

"L'État a souhaité se doter, au niveau national, d'une série d'indicateurs destinés à suivre l'évolution de la santé de la population en France. Depuis sa création en 1998, le Département santé travail (DST) de l'Institut de veille sanitaire (InVS) s'est attaché à développer des programmes de surveillance, afin de produire régulièrement de telles données et contribuer ainsi à améliorer la connaissance des risques professionnels. Les sources de données se sont étoffées au fil du temps, et le DST a mis en place en 2009 un programme de production régulière d'indicateurs destinés à rendre compte à l'échelle nationale de la situation concernant des problèmes de santé en relation avec l'environnement professionnel, ainsi que de leur évolution au cours du temps. Ces indicateurs sont établis à partir de différentes sources. Ce troisième numéro porte sur les troubles musculo-squelettiques (TMS) du membre supérieur. Dans ce document, le lecteur trouvera des données sur leur fréquence en termes de prévalence et d'incidence, ainsi que sur la fréquence des expositions aux principaux facteurs de risque connus, selon le sexe, l'âge, les catégories professionnelles et les grands secteurs d'activité. Il trouvera également des informations sur la part des TMS des membres supérieurs attribuable au travail, selon les catégories professionnelles et les grands secteurs d'activité et sur l'ampleur de la sous-déclaration au titre des tableaux de maladies professionnelles indemnisables. Enfin, un certain nombre de questions permettent de mettre en perspective les résultats présentés."

The effects of a downward-tilting (DT) keyboard tray on wrist posture, seated posture and self-assessed musculoskeletal discomfort were investigated in a field experiment. Thirty-eight professional office workers were studied. A pretest assessed how they typed using either a conventional keyboard on a desk or on an articulating keyboard tray, and with or without wrist rests. Workers were randomly allocated to a control (n=15) or test group (n=23) that used their existing keyboard in a DT system. A post-test was conducted 3 weeks later. Results showed no significant changes in wrist posture, seated posture or reports of musculoskeletal discomfort for the control group, and ~ 50% of typing wrist movements put the hand in a neutral zone. There were significant improvements in wrist posture, seated posture and upper body musculoskeletal discomfort for the test group using the DT system. Over 80% of typing wrist movements put the hand into a neutral zone with the DT arrangement. Reactions to using a conventional keyboard on a DT system were positive.