Dr. Joy Ebben Addresses Carpal Tunnel Syndrome
By Joy M. Ebben, Ph.D, CPE
Human Factors and Ergonomic Specialist, IAC Industries, Brea, Calif.
In the April issue of Occupational Health & Safety magazine, an
article authored by Dr. Joy Ebben discusses symptoms, causes,
and treatment for carpal tunnel injuries suffered in the industrial
workplace.
In “It’s Not Just With Keyboards, “ Dr. Ebben relates how long
scars on the wrist of a bellhop helping with her luggage led
her to surmise correctly that he had undergone carpal tunnel
surgery. He had incurred his injuries on an assembly line job,
where although the parts he handled were not heavy, he used
physical force to snap them into place at a work pace set by
a conveyor belt. Thus, the job involved repetitive forces an
awkward postures – thought to be among the major contributors
to carpal tunnel syndrome (CTS) injuries.
As Dr. Ebben’s article explains, CTS is a nerve entrapment
disorder that takes its name from the “carpal” bones of the wrist.
The tendons that control finger flexion and the median nerve, one
of three nerves that transmit motor and sensory impulses from
the hand to the central nervous system, pass through a tunnel
formed in each wrist. Compression of this nerve causes the
numbness, tingling and discomfort that are the symptoms
of CTS.
In the following excerpt from her article, Dr. Ebben offers specific
recommendations for eliminating or reducing CTS risks factors in
an industrial workplace:
- A few workstation design characteristics can have a significant
impact on reducing the risks of CTS during high repetition of
awkward postures, especially when exerting force.
- Provide the correct working height for repetitive task
performance. Having he work surface height either too height
or too low can lead to the selection of an awkward posture of
the wrist while performing tasks.
- Angle parts cups so when parts are repeatedly retrieved, the
wrist is allowed to stay in a neutral posture.
- Provide features so assemblies can be easily positioned to
allow repetitive forceful job tasks to be performed with neutral
wrist postures and less force.
- Provide holding fixtures so parts do not have to be held in
place when being work on, reducing force and awkward
postures.
- Provide appropriate lighting to make product inspection
possible without having to manually manipulate a surface,
reducing force and awkward wrist postures.
The good news is that workers comp, lost workdays, and other
costs related to CTS – one of the more expensive illnesses in the
workplace – seem to be declining. The trade magazine CTD News
reported a 45% decrease in CTS direct costs from 1996 ($4,764
per case) to 1998 ($2,126 per case) in industry and office
environments.
“CTS is often preventable,” Dr. Ebben sums up. “Try to keep
your wrists in a neutral posture, use tools and techniques that
minimize required force, have a proper working surface height,
design and arrange your work space to minimize the CTS risk
factors, and make sure to have enough breaks to have sufficient
recovery time.”
The article addresses CTS causes and prevention in detail.
If you have a customer with an interest in this particular
workplace injury, look for the complete article in the April issue of
Occupational Health & Safety.
