The International Organization for Standardization (ISO) published a new Technical Specification (TS), ISO/TS 20646-1 "Ergonomic procedures for the improvement of local muscular workloads (LMWL)--Part 1: Guidelines for reducing local muscular workloads" in 2004. However, little is known about whether the ISO/TS is really effective in taking action to improve the work conditions in real workplaces. This paper discussed the impact of preventive activities planned and carried out according to the ISO/TS in 17 enterprises. Results indicated that 61 improvements (96%) had already been implemented (63%) or in progress (33%) within 6 months of the start of the activities. Besides the initial improvements, new improvements added within one year reached 84 cases and 10 cases were in progress in 15 enterprises. Comprehensive risk analysis, which consisted of a series of applications of action oriented checklist and group discussions, contributed to the detection of widely diversified risks in each local workplace, and this seems to lead to sustainable activities for prevention of WMSDs. These results suggest that the ISO/TS 20646-1 help managers and workers to control multiple work-related musculoskeletal disorder (WMSD) risks on their own initiative and promote sustainable activities.