Table 4.

Results of Cox regression analyses for three simultaneous biomechanical exposures: manual handling ≥50 N ≥ 60 min/day, working with hands above shoulder level ≥30 min/day, and working with vibrating tools ≥60 min/day, comprising adjusted relative chance of being symptom-free from neck/shoulder pain at the end of the study (RC) and 95% confidence intervals (95% CI), for increasing number of exposures

	RCa	95% CI	Subjects with neck/shoulder pain at baseline
			Total	Symptom-free at the end of the study	(%)
Biomechanical exposuresb
0	1.00		525	196	(37)
1	0.89	0.68–1.18	187	71	(38)
2 or 3 simultaneous exposures	0.61	0.40–0.94	90	26	(29)

Also shown for each exposure category are the total number of subjects and the number and proportion (%) of subjects being symptom-free from neck/shoulder pain at the end of the study

^aAdjusted for sex and age

^bIncluded variables: manual handling ≥50 N ≥60 min/day, working with hands above shoulder level ≥30 min/day, and working with vibrating tools ≥60 min/day