After engineering and work-method considerations have been addressed, personal protective equipment is the final step toward reducing the potential risk of ergonomic injury on the assembly line. Back supports, wrist supports and antivibration gloves act as barriers to control how an identified risk interacts with the body. These devices stabilize human joints when they are under stress during repetitive motion.

Back Supports

Special lifting belts are used in many work environments. In fact, there are more than 70 types of industrial back supports on the market. But, their overall usefulness is controversial. Even the National Institute for Occupational Safety and Health (NIOSH, Washington, DC) has challenged their effectiveness. In fact, a recent NIOSH study found "no evidence that back belts reduce back injury or back pain."

Despite that landmark study, which focused on retail workers who lift or move merchandise, some observers argue that back supports can protect assemblers against ergonomic risks.

"My personal belief as to why there is controversy about the usefulness of lifting belts has more to do with how people are actually using them," says Tray Working, president of CMO Inc. (Barberton, OH), a leading manufacturer of back supports. "The quality of the different belts available in the marketplace is also quite different. Some belts out there are only good enough to hold up your pants. There has been this mistaken viewpoint in the marketplace that if it is black and goes around the waist, that makes it a lifting belt."

Working says construction, material selection and design are critical to the effectiveness of a lifting belt. "Design features in any good industrial belt will have overlapping abdominal or cinch straps," he explains. "While many available belts have little elastic belts that will come together and touch, they don't crisscross." According to Working, the crisscross design gives excellent abdominal support, which is crucial to good lumbar support.

He says good fit is also very important. Back support belts should be tailored to fit evenly on the top and bottom so they don't roll up on the wearer. Working says a quick test for fit is to lay the belt out flat. "If it is straight, it will not fit," he warns. "It will be tighter at the hips than the waist, with the result being belt migration from where it needs to be.'

Suspenders do not add to the support of the belt. "The only thing they do is keep the belt from falling off when you open it," says Working. "Often, I see workers wearing belts incorrectly. It won't work unless they are wearing it correctly. We are talking about lumbar support so the belt needs to be there, not higher or lower."

Expectations also play into the potential failure of lifting belts to protect workers. "When you put on a lifting belt you don't become Arnold Schwarzenegger," warns Working. "You can't lift more than you can without the belt, nor can you ignore good lifting practices and techniques."

Other manufacturers of industrial back supports include Allegro Industries (Garden Grove, CA), Ergodyne (St. Paul, MN), FLA Orthopedics Inc. (Miramar, FL), OccuNomix International Inc. (Port Jefferson, NY), OK-1 Manufacturing Co. (Altus, OK) and Smith Orthopedics (Topeka, KS).


Gloves protect assemblers from dirt, oil, adhesive, solder paste, burrs, sharp objects, extreme temperatures and vibration. Gloves with secure gripping materials on the palm also can protect, of all things, a worker's back. A secure grip on workpieces or tools ensures the operator will not flinch or react negatively if they slip out of his hands.

For gloves to do their job, workers have to wear them. "The key driver is comfort, which is the benchmark to which any glove is measured," says Ray Morris, global sales training manager at Ansell Occupational Healthcare (Coshocton, OH). A comfortable glove is one that will be used consistently by the worker.

Problems arise with choosing gloves that are bulky, uncomfortable to wear, or interfere with a worker's ability to do his job. "Typically, gloves are bulky and viewed as a necessary evil to keep workers safe," says Morris. "Surveys of injured workers show many were not wearing the gloves provided by their employer for just those reasons."

Workers who use pneumatic fastening tools, such as riveters, require gloves that can absorb vibration. Correctly absorbing tool vibration helps avoid potential white finger syndrome or hand-arm vibration syndrome (HAVS). Caused by lengthy exposure to vibration, the syndrome results from constriction of small blood vessels in the fingers and hands. Reduced blood flow to the fingers can lead to loss of touch sensitivity and permanent damage.

"This is a widely recognizable disease in industry," says Morris. "The syndrome is irreversible, often leading to worker disability, a situation that neither the worker nor the employer wants.

"What differentiates our product from others is the material we use to absorb vibration," claims Morris. Many competitive gloves use only foam rubber or ordinary visco-elastic material. Ansell's VibraGuard gloves use Gelf?m, a unique composite material that Morris says is known for its vibration-reducing characteristics. A nitrile coating over these Gelf?m pads provides abrasive protection and longer glove life.

Ergodyne (St. Paul, MN) uses reinforced fingertips and thumb saddles in its ProFlex 710 gloves to protect the hand during twisting, turning or pushing. Incorporating Akton gel in the palm protects the hand against impact.

To combat vibration, Ergodyne offers two vibration-reducing gloves. Both feature the company's patented Nu202 polymer, which dampens vibration in excess of specifications of ISO 10819, which addresses hand-arm vibration risks. The Nu202 polymer is thin, so the gloves are not bulky and are comfortable to wear. The pigskin leather of both gloves is durable and breathable and conforms to the shape of the hand, while a PVC shell on one model provides extra protection on the back of the hand.

Perspiration is another ergonomic design concern to consider when selecting gloves. "Cotton liners are good for perspiration," says Morris. "We use specialty fibers that can be put in the liner to provide wicking. When a glove traps heat, it is important that you remove moisture to give the sensation of coolness to the skin of the hand."

Other manufacturers of antivibration gloves include Allegro Industries (Garden Grove, CA), CMO Inc. (Barberton, OH), OccuNomix International Inc. (Port Jefferson, NY) and OK-1 Manufacturing Co. (Altus, OK).

Wrist Braces

Ace bandages or tape don't provide the support necessary to stabilize a wrist joint under stress. Only a correctly designed industrial wrist brace or splint provides stability, lightweight construction and some dexterity.

The Carpal Lock from CMO Inc. is specially designed for repetitive assembly applications. "Conventional wrist splints support the wrist but reduce dexterity," says Tray Working. "We wanted a design with support that maintained dexterity."

Working claims the product does not inhibit movement. Its unique dorsal splint leaves the hands free while supporting the wrist as protection against carpal tunnel syndrome. The open design makes this splint lightweight and cool to wear.

ProFlex wrist supports from Ergodyne (St. Paul, MN) are lightweight, fully adjustable for a good fit, and limit certain wrist movement to reduce the risks of carpal tunnel syndrome. A Neoprene body cloth on Model 4020 conforms to the hand and wrist for a glove-like fit, while interior ventilation holes keep the hand cool and dry.

Other manufacturers of industrial wrist braces include Allegro Industries (Garden Grove, CA), FLA Orthopedics Inc. (Miramar, FL), OccuNomix International Inc. (Port Jefferson, NY) and OK-1 Manufacturing Co. (Altus, OK).