‘Sick worker’ malady may be early RSI sign: study

By JoAnne Allen

WASHINGTON (Reuters) – Early nerve damage caused by
repetitive motion on the job can cause “sick worker” syndrome,
a fatigue or depression that can be mistaken for poor work
performance, according to a study published in this month’s
Journal of Neuroimmunology.

The study done on rats found that nerve injuries caused by
low-force, highly repetitive movement — common to typists,
pianists and meatpackers, among other professions — can be
blamed on increased production of proteins known as cytokines.

Cytokines show up in injured nerves as early as three weeks
after the first signs of cell stress, much earlier than
previously thought, researchers at Temple University found.

Cytokines also are known to spark symptoms of malaise and
the study concludes that an onslaught of these proteins
affected the rats’ psychosocial responses, the researchers
said.

With so many cytokines entering the blood stream so early,
some apparently traveled to the brain, sparking the rat version
of “sick worker” syndrome, the study said.

“At three weeks, even before the rats experienced pain from
their wrist injuries, we watched them self-regulate their work
behavior,” researcher Ann Barr said. “With inflammatory
proteins in the bloodstream, they began to slack off from
completing their tasks.”

By five weeks to eight weeks, when cytokine production
reached “peak” levels, some rats curled up in a ball and slept
in between tasks, the study said.

The researchers theorized that as cytokines first appear in
the newly injured nerve of workers who perform the same
physical movement over and over, signs of “sick worker”
syndrome begin. People may call in sick with undefined
symptoms, or slow down their work production or a low-grade
depression may set in, the researchers said.

Some bosses might see the cytokine connection as an excuse
for employees to slack off work, but Temple researcher Mary
Barbe disagrees.

“Cytokines are self-protective,” she said. “This undefined
feeling of malaise may be telling the body to take some time
off to heal, before things get worse.”