SOURCES: Maria-Gabriela Garcia, Ph.D. candidate, Sensory-Motor Systems Lab, department of health sciences and technology, ETH Zurich, Zurich, Switzerland; Kermit Davis, Ph.D., graduate program director, environmental and occupational hygiene program, University of Cincinnati; June 2015, Human Factors, online
TUESDAY, July 28, 2015 (HealthDay News) -- Desk jobs aren't good for your health, but working on your feet could spell trouble, too, researchers say.
Standing five hours a day contributes to significant and prolonged lower-limb muscle fatigue, a small study concluded. This may raise your risk for long-term back pain and musculoskeletal disorders.
This isn't good news for the millions of bank tellers, retail assistants, assembly line workers and others who earn their living on their feet. The study authors pointed out that almost half of all workers worldwide spend more than three-quarters of their workday standing.
Two hours of standing on the job is not associated with problems, but "a longer period is likely to have detrimental effects," said study lead author Maria-Gabriela Garcia, a doctoral candidate within the department of health sciences and technology at ETH Zurich in Switzerland.
The findings were published online recently in the journal Human Factors.
Standing for long periods is already associated with a higher risk for short-term problems, such as leg cramps and backaches. But the current study set out to see whether prolonged standing also raised the risk for developing longer-term issues.
The investigators focused on 14 men and 12 women. Half were between 18 and 30 years old, and half between 50 and 65. None had a history of any neurological or musculoskeletal disorder, and all were asked to refrain from high-level exertion the day before study participation.
Replicating a shift at a manufacturing plant, all were asked to simulate light tasks while standing at a workbench for five hours with five-minute rest breaks and one half-hour lunch break.
Posture stability and leg muscle stress (quantified as "muscle twitch force") were monitored throughout, and participants were asked to report on discomfort.
The result: Regardless of age or gender, participants were equally likely to experience significant fatigue at the end of the work day. What's more, clear signs of muscle fatigue were observed for more than a half-hour after the standing period ended, regardless of whether the participants actually felt the strain.
Because the study was small and of very limited duration, it doesn't prove that a job that requires prolonged standing will harm your health, the authors noted.
Still, Garcia said more research is needed to find ways to help workers deal with the difficulties of long-term standing.
Regular stretching exercises and "perhaps the incorporation of specific breaks, work rotation or the use of more dynamic activities could alleviate the effects of long-term fatigue," Garcia said. Alternating seated and standing work is also beneficial, she said, "as it alleviates both the issues with prolonged sitting and prolonged standing."
Another expert agreed with the need for frequent breaks and change in positions.
"Basically, the body does not like to have the same posture or load placed on it continuously, so change is always good," said Kermit Davis, graduate program director for environmental and occupational hygiene at the University of Cincinnati. "[You want] routine breaks where you get the blood moving," he added.
"One of the easiest implementations to deal with the problem is to have routine breaks every 30 or so minutes, where [workers] stand-up or move around [to] deliver paperwork, file papers in file cabinets, copy something, or use the restroom," Davis said. His own research, he explained, has suggested that regular breaks do not undermine worker productivity.
When relevant, he said, it's also important that work stations are set at the proper height and distance from workers.
If your job requires prolonged standing, see the Canadian Centre for Occupational Health and Safety.