Table 5 Number of cases with prevalent upper extremity musculoskeletal symptoms (UEMSS) over the 4-month and 8-month follow-up period in the intervention and control groups among the population that had experienced symptoms at baseline

	UEMSS 4 months	No UEMSS 4 months	UEMSS 8 months	No UEMSS 8 months	Intervention versus control RR (95% CI)
Intervention group (n = 33)	17	16	20	13	4 months: 1.2 (0.7 to 1.8)
Control group (n = 50)	22	28	34	16	8 months: 0.8 (0.6 to 1.3)
Total (n = 83)	39	44	54	29

RR, relative risk.