Occupational musculoskeletal disorders in the neck and upper limbs of forestry workers exposed to hand-arm vibration

Abstract

An epidemiologic and clinical study of neck and upper limb musculoskeletal disorders was carried out on 65 vibration-exposed forestry operators using chain-saws and 31 comparable control subjects (maintenance workers) performing manual activity and not exposed to vibration. Upper limb function was evaluated by measuring finger and wrist circumference size, maximal hand grip strength and range of motion manoeuvres in both the controls and the exposed workers. Vibration from two chain-saws was measured, and vibration exposure for each forestry worker was assessed in terms of 4 h energy-equivalent frequency-weighted acceleration according to ISO 5349. Job analysis indicated a slight excess risk of upper extremity cumulative trauma disorders (CTDs) in the forestry operators compared with the control workers. After adjustment for age and body constitution, significantly higher prevalence rates of persistent upper limb pain, muscle-tendon syndromes and carpal tunnel syndrome were observed among the forestry workers than among the controls. In the forestry operators, the occurrence of upper limb musculoskeletal disorders increased with increasing vibration exposure. Upper limb function was found to be impaired in the forestry workers compared with the controls. Vibration exposure was significantly related to increased finger circumference size, diminished muscle force and reduced joint function. Even though it is difficult to establish the relative importance of vibration and ergonomic factors in the aetiology of CTDs, nevertheless the results of this study indicate that musculoskeletal impairment to the upper limbs was more severe in the forestry operators than in the controls who did solely manual work. This finding and the observed dose-effect relationships suggest that vibration stress is an important contributor to the development of musculoskeletal disorders in workers using hand-held vibrating tools.

Work relatedness of chronic neck pain with physical findings—a systematic review

“…The reproducibility of the diagnosis was demonstrated for 4 of the studies (18,35,37,38) and suggested in 2 others (39,63). Blinded assessment of outcome was explicitly declared in 5 studies (18,35,37,43,61), but may have occurred in several others by virtue of design or previously described methodology (19,38,58,65).…”

“…In 14 of the 21 reports, the analysis was principally carried out through a comparison of job titles, but, in 11 studies, physical exposures were objectively characterized to a varying extent (18,37,(39)(40)(41)(42)(43)(61)(62)(63)(64). Several studies offered exposure-response information by quantified level of exposure (18,37,61,62) or time worked in the job (35,38,41), but in others only crude and sometimes composite exposure variables were used. Three studies analyzed the interaction between physical exposures (18,37,43).…”

“…We rated the overall quality of information as excellent (+++++) (18,37) for only two reports, as useful but with important limitations for four reports (+++) (19,41,61,62), as moderately informative (++) for five reports (35,38,42,43,64), and as limited for 10 reports (+) (32, 39, 40, 44, 50, 58-60, 63, 65 Åkesson et al (59) compared 84 dental personnel with 27 age-and gender-matched nurses. The details of the sampling frame and selection methods were limited.…”

“…Altogether 15 investigations were cross-sectional in design (32,35,37,(39)(40)(41)(42)(43)(44)(59)(60)(61)(62)(63)(64), 4 were prospective (18,19,38,58) [1 mostly focusing on baseline findings (38)], and 2 were community-based case-referent studies (50,65). The studies ranged from very large (N >15 000) (19) to very small (N=30) (58).…”

Associations between work-related factors and the carpal tunnel syndrome—a systematic review

“…A total of 14 articles described significant differences in the occurrence of CTS between occupations, the OR values ranging from 1.86 to 76.5 (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32). In eight studies, no significant differences were observed, the OR values ranging from 0.91 to 1.63 (33)(34)(35)(36)(37)(38)(39)(40).…”