The study was published in the July 2007 issue of the peer-reviewed journal, American Journal of Industrial Medicine. It is available online at http://www2a.cdc.gov/nioshtic-2/BuildQyr.asp?s1=20032255&f1=%2A&Startyear=&Adv=0&terms=1&EndYear=&Limit=10000&sort=&D1=10&PageNo=1&RecNo=1&View=f.

The researchers followed 51 workers for eight weeks. For half of the study, participants had conventional work breaks (two breaks per day, 15 minutes each). For the other half of the study, they had the conventional breaks along with four supplemental breaks per day, five minutes each. Discomfort and eyestrain were gauged through responses to questionnaires, and productivity through electronically recorded measures. Findings included these:

• Participants’ ratings of discomfort and eyestrain were significantly lower with supplemental breaks. The supplementary breaks also attenuated the accumulation of discomfort during work sessions.
• Data-entry speed was significantly faster with supplementary breaks, so that work output was maintained even though 20 minutes of work were replaced by the supplementary breaks over the work day.
• The study also attempted to gauge whether stretching exercises helped to reduce discomfort. No significant differences in discomfort were observed between employees instructed to perform stretching exercises and employees not instructed to perform stretching exercises as part of the study. However, employees in the exercise group skipped the exercises during most of their breaks. Further research on exercise motivation and the effects of exercise is suggested in the paper.

NIOSH will incorporate the findings among other data in designing ongoing research for preventing work-related musculoskeletal injuries, and assessing potential interventions.

"Data entry is a fundamental task in today's service and information industries, and often it is a first job for high school graduates," noted NIOSH Director John Howard, M.D. "Some observers have suggested that supplementary breaks may alleviate risks for work-related repetitive stress injuries, while other observers have expressed concern as to whether such breaks may adversely affect productivity. There exists a dearth of scientific data to help employers and employees weigh these questions. The new study helps to fill that gap and demonstrates that rest breaks can have a double benefit of reducing the risk of occupational injury while helping businesses maintain productivity."

The new study follows up on and expands earlier research reported in 2000.