Temporal factors and the prevalence of transient exposures at the time of an occupational traumatic hand injury.

Temporal factors and the prevalence of exposure to transient risk factors for occupational traumatic hand injury were analyzed among 1166 subjects participating in a case-crossover study. Temporal factors included time of injury and elapsed time to injury since the start of the work shift. Transient exposures included work equipment, work practice, and worker-related factors. The highest frequency of injury was observed from 08:00 am to 12:00 pm (54.6%), with a peak from 10:00 to 11:00 am (14.9%). The median time into the work shift for injury was 3.5 hours. Subjects injured 2 to 3 hours into their work shift most often reported using a machine, tool, or work material that performed differently than usual (23.9%). These results suggest that acute hand injuries occur earlier in the workday and safety programs should place increased vigilance on these times.