Michel Aptel

Work-related musculoskeletal disorders of the upper limb

Work-related musculoskeletal disorders of the upper limb (WRMSDs-UL) account for over two-thirds of all occupational disorders recognized in France. This broad term encompasses a vast array of disorders whose development is facilitated by environmental factors present at the workplace. Numerous epidemiological studies have established the key role of occupational activities in the genesis of WRMSDs-UL. This role is mediated by biomechanical factors (repetitive motion, strenuous effort, extreme joint postures) and/or psychosocial factors. Biological plausibility supports the epidemiological data. The high incidence of WRMSDs-UL indicates a need for greater emphasis on prevention.

Integration of Ergonomics Into Hand Tool Design: Principle and Presentation of an Example

The development of ergonomic tools responds to health protection needs on the part of workers, especially the work related musculoskeletal disorders of the upper limbs and to the development of ergonomic tools to take into account the needs of the factories. Only an ergonomic design process can enable tool manufacturers to meet these requirements. Three factors are involved: integration of ergonomics into the design process, definition of the different ergonomic stages involved, and finally knowledge of the different factors involved in hand tool design. This document examines these 3 elements in more detail and presents briefly a project of research whose main purpose is to integrate ergonomic criteria into a design process.

Biomechanical stresses in computer-aided design and in data entry.

A study of the risk factors of musculoskeletal disorders (MSDs) of the upper limbs was carried out on 2 populations, 1 performing a computer-aided design (CAD) task and the other performing a data entry task. A questionnaire on MSD complaints and working life was completed by a sample of each population. Biomechanical measurements of the forces, the angles, and the repetitiveness of movements of the upper limbs were carried out on some operators in each sample. It emerged that complaints of the upper limbs seem to be linked to the use of input devices. The grip forces exerted when using the keyboard and mouse were higher in CAD than in data entry.

Prévenir les troubles musculosquelettiques du membre supérieur : un enjeu social et économique: Prevention of work-related muscular-skeletal disorders of upper limbs: a social challenge and economic obligation

Work-related muscular-skeletal disorders of upper limbs (WRMSDul) represent 66% of all occupational injuries and diseases (OD). The total number of cases has multiplied by 8 over the past eleven years, and in 2002 there were 21126 OD incidents recorded. Although OD statistical data are not necessarily a truly precise reflection of the reality of associated risks, examination of these trends shows that over the past 10 years the most serious diseases, like rotator cuff tendonitis, have increased more rapidly than have the totality of WRMSDul cases as a whole. It is likely that the number of injured workers will continue to increase over the course of the coming years. An evaluation of indirect costs also demonstrates that there are significant social consequences associated with these diseases and which put into question the employability of the affected workers, who are often aged between 40 and 60 years old. This paper therefore brings to the surface the importance of prevention principles and proposes an ambitions prevention plan. This emblematic occupational health risk will constitute, along with professionally related cancers, one of the major challenges for prevention in the coming years.

Les troubles musculosquelettiques du membre supérieur liés au travail

Resume Les troubles musculosquelettiques du membre superieur representent plus des deux tiers des maladies professionnelles reconnues en France. Cette expression parapluie designe a la fois de nombreuses pathologies et le fait que des sollicitations environnementales favorisent leur developpement. De nombreuses etudes epidemiologiques ont montre limportance du travail dans la survenue de ces affections. Ainsi, des facteurs de risque biomecaniques (repetitivite, efforts, postures articulaires extremes) et psychosociaux ont ete mis en evidence. Des elements de plausibilite biologique confortent la validite des etudes epidemiologiques. Le taux dincidence eleve de TMS implique une reflexion sur les modalites de prise en charge des patients, accordant une plus large place a la prevention.