From The Ergoweb® Learning Center

Be Careful Gripping That Hammer

The likelihood of acquiring carpal tunnel syndrome (CTS) is nearly four times greater for male blue collar workers and nearly three times greater for female blue collar workers compared to a cross section of general population occupations, according to a recent prospective French study involving 1135 subjects over a three-year period.  Specifically, males working in the construction trades had three times the risk of developing CTS compared to all industrial sectors.

Male and female blue collar workers contributed nearly 50 percent and nearly 20 percent, respectively, to the CTS cases reported within the general population of Maine-et-Loire, a French region of approximately 400,000 individuals, in the 20-59 age group.

The incidence of CTS among female, lower-grade, white collar workers (i.e., services, sales and public employees) occurred at twice the rate of all occupations and led to nearly 25 percent of the general population cases.

The Bottom Line – How This Applies To Ergonomists

Effective CTS prevention programs conducted among blue collar occupations (for both genders) and female white collar workers could potentially significantly reduce the incidence of carpal tunnel syndrome within a general population.

The population-attributable fraction (the relative risk of a specific group developing CTS compared to the relative risk of the general population developing CTS) offers a good method of evaluating the impact of an occupation on the incidence of a condition.  Since the impact of select occupations is so high relative to CTS incidence, a public policy mandating that CTS risk factors in key professions be evaluated/controlled would likely ease the societal burden of this disorder.

Other Key Study Points

The economic structure of the Maine-et-Loire region was diversified and similar to most regions of France.

The population-based annual incidence rate of CTS was 1.4 per 1000 females and 0.6 per 1000 males.

Obesity and diabetes mellitus prevalence was 16 percent and 4 percent, respectively, among study subjects. The prevalence of thyroid disorders was 13 percent among females. Those with diabetes mellitus and/or obesity had CTS at twice the rate as the general population.

Study Methods

New cases of CTS among those who lived in the Maine-et-Loire region were eligible for the study.

A carpal tunnel case was defined as having a positive electrophysiological study combined with a standard clinical presentation. Incidence was based on a per person criteria (not per wrist).

When a CTS case was found, the study subject was asked to complete a self administered questionnaire involving medical history (i.e., body mass index, diabetes mellitus, wrist/hand trauma, and upper extremity musculoskeletal disorders) and employment (i.e., place of employment, occupation, and task description during the prior five years). The occupations of interest included:

  • Farmers
  • Craftsmen, sales personnel, and managers
  • Professionals
  • Technicians, associate professionals
  • Lower-grade, white collar workers
  • Blue collar workers
  • Pensioners and other non-working persons

The industrial sectors of interest included:

  • Agriculture
  • Construction
  • Manufacturing
  • Service industries

Gender-specific relative risk for CTS was calculated for industrial sectors and occupational categories.  Also, the percent of the regional population that sustained a CTS case for a given gender/occupation/industrial sector was calculated. 

Research Limitations

A causal factor between workplace risk factors and all CTS cases is assumed in the calculation of study statistics.

The authors acknowledged that no precise workplace risk factor evaluation was performed for this study (exposure was assumed based on occupational category and industrial sector).


This position paper can be acquired at:

Article Title: Attributable risk of carpal tunnel syndrome in the general population – implications for intervention programs in the workplace.

Publication: Scandinavian Journal of Work, Environment & Health, 35(5):342-348, 2009

Authors: Y Roquelaure, C Ha, N Fouquest, A Descatha, A Leclerc, M Goldberg, and E Imbernon

This article originally appeared in The Ergonomics Report™ on 2009-11-04.