Feeling tired and sluggish on the job isn't just a sign you're getting sick or you aren't happy at work. Research shows it could also signal the onset of a repetitive strain injury such as carpal tunnel syndrome.
A study published in the Journal of Neuroimmunology found that rats which performed highly repetitive tasks using negligible force (HRNF) had elevated levels of cytokines - proteins associated with inflammation - shortly (3 weeks) after the first signs of cell stress. These levels continued to escalate and then peaked by five to eight weeks.
Increased levels of cytokines are associated with symptoms of malaise, such as fatigue and depression. "Cytokines are self-protective," said researcher Dr. Ann Barr in a news release. "This undefined feeling of malaise may be telling the body to take some time off to heal, before things get worse."
The researchers tested cytokine levels in rats that had learned to reach for food at a rate of eight reaches per minute and which performed the task repeatedly for two hours per day, three days per week, for up to eight weeks. They compared these levels to rats that weren't required to perform the task.
"At three weeks, even before the rats experienced pain from their wrist injuries, we watched them self-regulate their work behaviour," said Barr. "With inflammatory proteins in the bloodstream, they began to slack off from completing their tasks."
By the time cytokines reached peak levels, some of the rats curled up into a ball and slept in between reaches.
Could these results explain why, as humans begin to develop repetitive strain injuries at work, they may appear to slack off, calling in sick or reducing productivity? To explore this theory, the researchers are currently conducting a study measuring cytokine levels in people who have been diagnosed with repetitive strain injuries.
According to Statistics Canada, an estimated 2.3 million Canadian adults are affected by repetitive strain injuries. In order to reduce your risk, try taking frequent breaks to bend and stretch your wrists. If you type or play the piano, keeping your wrists straight and improving your posture can also help.