Relationship between repetitive work and the prevalence of carpal tunnel syndrome in part-time and full-time female supermarket cashiers: a quasi-experimental study
- 548 Downloads
To investigate the prevalence of Carpal Tunnel Syndrome (CTS) in full-time and part-time supermarket cashiers exposed to a different weekly duration of biomechanical load.
All the 269 cashiers and 127 office workers were asked to participate. The protocol included ergonomic risk assessment, collection of personal and clinical data and bilateral electrodiagnostic study of the median nerve. CTS symptoms were defined as past and/or current nocturnal and/or diurnal numbness, tingling, burning or pain involving at least one of the first three fingers. Results were evaluated according to two case definitions based on current symptoms and on the combination of current symptoms and slowing of sensory conduction velocity from wrist to palm, respectively. Difference in proportions of CTS symptoms and cases was evaluated by the Pearson’s chi-square (χ2) test, univariate and multivariate logistic regression analyses were performed to determine the impact of weekly exposure.
The final female study population included 71 full-time cashiers, 155 part-time cashiers and 98 office workers. Ergonomic risk level was rated 5 for hand activity level and 4 for peak of force according to ACGIH. The intersection of the two values fell on the threshold limit value line, confirming the possible exposure to biomechanical risk factors for CTS. The prevalence of current CTS symptoms was higher among full-time (31.0%) than in part-time cashiers (19.3%) or controls (16.3%) (p = 0.055). A similar pattern was found for CTS past symptoms and cases. Univariate analysis showed that full-time cashiers had a 2.3 fold increased risk for CTS specific current symptoms than control subjects. A similar trend also emerged for CTS cases but was not significant (Odds ratios 1.23). Multivariate logistic regression analysis confirmed the increased risk for CTS current symptoms in full-time cashiers.
Intensive manual work associated with inadequate recovery time might have generated an impairment of the median nerve at the wrist level proportionally increasing with duration of hand use. Our study can provide useful information both for ergonomic risk assessment and work organization.
KeywordsCarpal tunnel syndrome Supermarket cashiers Upper limb repetitive movements
- ACGIH Worldwide (2002) Threshold limit value for chemical substances and physical agents and biological exposure indices. ACGIH, Cincnnati, OH, pp 112–114Google Scholar
- Bernard BP (1997) Musculoskeletal disorders and workplace factors. a critical review of epidemiologic evidence for work-related musculoskeletal disorders of the neck, upper extremity, and low back. US Department of Health and Human Services (DHHS) (NIOSH National Institute for Occupational Safety and Health), Cincnnati, OH (Publication No. 97–141: Chapter 5 (a, b))Google Scholar
- Hagberg M, Silverstein B, Wells R, Smith MJ, Hendrick HW, Carayon P, Pérusse M (1995) In: Kuorinka I, Forcier L (eds) Work related musculoskeletal disorders (WMSDs): a reference book of prevention. Taylor & Francis, London, pp 17–138Google Scholar
- Jablecki CK, Andary MT, Floeter MK, Miller RG, Quartly CA, Vennix MJ, Wilson JR (2002a) Second literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome. Muscle Nerve Published online 1 June 2002 in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/ mus.10215
- Jablecki CK, Andary MT, Floeter MK, Miller RG, Quartly CA, Vennix MJ, Wilson JR (2002b) Practice parameter: electrodiagnostic studies in carpal tunnel syndrome. Report of the American Association of Electrodiagnostic Medicine, American Academy of Neurology, and the American Academy of Physical Medicine and Rehabilitation. Neurology 58:1589–1592Google Scholar
- Katz JN, Stirrat CR (1990) A self-administered hand symptom diagram for the diagnosis of carpal tunnel syndrome. J Hand Surg [Am] 15(2):360–363Google Scholar
- National Research Council, the Institute of Medicine (2001) Musculoskeletal disorders and the workplace: low back and upper extremities. Panel on musculoskeletal disorders and the workplace. Commission on behavioral and social sciences and education. National Academy Press, Washington, DC, pp 85–183Google Scholar
- Putz-Anderson V (1988) Cumulative trauma disorders. A manual for musculoskeletal diseases of the upper limbs. Taylor & Francis, New York, pp 21–25Google Scholar
- Rosenbaum RB, Ochoa JL (1993) Carpal tunnel syndrome and other disorders of the median nerve. Butterworth-Heinemann, Stoneham MA, pp 197–231Google Scholar