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What are wrist splints? Splints support the wrist. Some wrist splints are just wraps, such as an elastic bandage that provides external support to the wrist. Other splints keep the wrist straight (i.e. they prevent it from bending). These types contain a rigid element, such as a metal shank. This type of splint may be medically prescribed if a tendon or nerve is damaged in the wrist.
(Note: Some splints are prescribed by a physical therapist or doctor, as part of a person’s rehabilitation. This article does NOT address the use of splints in this context.)
Why do people wear splints? Workers wear splints when they feel their wrist or grip strength has been weakened. Splints help stabilize their wrists and give them greater support. Some employers give splints to all their workers who do repetitive hand work in an attempt to stave off painful disorders such as carpal tunnel syndrome. When used this way, splints are being used as personal protective equipment.
Ergonomically speaking, are splints a good idea? Generally not, because wrist splints do not prevent injuries. Although they may be prescribed by a physical therapist or orthopedic doctor for wrists that are already damaged, they don’t prevent injuries from developing in the first place. Why not? Because if the job requires the worker to bend his wrists (due to the way the job is set up), the splints will hinder his work, but won’t do much to keep him from hurting his wrists.
When a worker wears a splint on a wrist-bending job, usually one of two things will happen. If she's wearing an elastic wrap, she will fight against the splint, trying to bend her wrists in spite of the constraint. Or, if she’s wearing a rigid unbendable splint and she can’t bend her wrists, she’ll bend her elbows. Or maybe she'll raise her shoulders to compensate for the unbendable wrist.
You can see this clearly for yourself if you watch splinted workers from a distance. If they’re flinging their elbows sideways (we ergonomists call this “chicken wings”) or hiking up their shoulders (as in a “beats me” kind of a shrug), these are telltale signs that the wrist splints haven’t solved anything. They’ve merely transferred the bending motions from the wrists to the elbows or shoulders. And soon those joints will become achy and sore from repetitive bending. Now you’ve got workers with splinted wrists, and sore elbows or shoulders. Not good.
Solution: Redesign the job to eliminate the bending motions altogether. This may mean getting creative in the design of the workstation:
• Parts bins-Check the vertical height, horizontal distance, size and tilt of the openings.
Your goal is to reduce the amount of total motions-not just wrist movements, but all the movements of the upper body. Also look at the amount of weight being lifted or the amount of force being exerted. The less effort, the less wear-and-tear on the worker, especially in a fast-paced or highly repetitive job. Too much wear-and-tear is what causes those repetitive motion injuries.
This is the right way to correct a significant ergonomic risk factor.
Delia Treaster, Ph.D., is a certified professional ergonomist and writes on various ergonomic issues, drawing on decades of experience in occupational ergonomics. She has been an ergonomic contractor with Humantech, one of the largest workplace ergonomics consulting firms in the United States. Prior to working for Humantech, Delia was an ergonomic consultant for the U.S. Postal Service, a senior ergonomic specialist with Travelers Insurance, and a research scientist at Battelle Memorial Institute. She has a master’s degree in human factors engineering and a Ph.D. in biomechanics from Ohio State University.
E-mails to Delia can be sent to email@example.com.
Editor’s note: “Ergo Corner” is part of a series of guest spots by industry experts that will appear regularly on ASSEMBLY’s blog page. Check back frequently to read more commentaries from Delia, as well as contributions on product testing, automated assembly systems, electronics assembly and robotics.