Many American-based maintenance and assembly operations have reduced worker injury rates and improved workforce productivity by switching to genuine ergonomic hand tools. Ergonomic tools are still relatively new to the industry. But since 1995, they have received broad attention, especially for the reported decline in Cumulative Trauma Disorders (CTDs) in hand tool intensive operations.

CTDs are repetitive strain injuries (RSIs). They occur most often when workers perform repetitive tasks with the same hand movements over an extended period of time. Most often, RSIs cause employees to go on disability, and employers lose thousands of dollars a year while workers recuperate. For example, one case of Carpal Tunnel Syndrome can cost an employer $30,000.

However, true ergonomic hand tools effectively reduce the musculoskeletal effort and stress required in performing repetitive handwork, thus reducing the risk of worker injury. And despite the higher price tag associated with ergonomic tool design, the cost is often justified through reduced injury claims and improved worker productivity. Consider the payoffs of ergonomic design in these hand tool intensive operations:

Item: A high-volume electronic assembly operation in Massachusetts manually trimmed wire leads on circuit boards for various products utilizing standard wire cutters.

The repetitive handwork resulted in approximately 50 cases of RSIs in a single year and lost worker productivity. The company then designed new ergonomic wire cutters for their workers with help from Lindstrom, a Bahco Tools Inc. company. The assembly operation now logs only one or two cases of RSIs per year, and worker comfort and productivity has also improved.

Item: An Oscar-winning electronics manufacturer in California used standard wire clippers to trim wire leads on digital cinema processors for movie theaters. However, the company discovered that electronic industry workers elsewhere had suffered expensive injuries, including debilitating Carpal Tunnel Syndrome, when doing similar repetitive handwork. So to prevent RSIs in its operation, the company worked with a manufacturer with a proven ergonomic design process to develop new cutters and pliers to alleviate the stress on workers’ hands and fingers.

Since implementing the new ergonomic cutters and pliers, the electronics manufacturer has reported no new cases of RSIs.

Both of these operations switched from standard hand tools to a new generation of ergonomically designed hand tools. While any tool can carry an ergonomic label, those described above are products of a specialized ergonomic design process. This process requires ergonomic tools to be thoroughly researched and tested in order to validate the real differences they make to the user. Let’s now examine this aspect more closely.

Genuine Ergonomic Design Process
Some manufacturers use the term ergonomic to imply quality. A nicely packaged tape measure is labeled ergonomic even though the tool does nothing to remedy RSIs. For instance, cushioned grips on hand tools are commonly perceived as being ergonomic, even though the designers cite no research to explain how the padding protects the hand.

However, with a little bit of time and research, industrial-duty hand tool users can avoid false ergonomic hand tools. The research involves locating manufacturers that have a proven history of ergonomic design. One such manufacturer is Lindstrom. They have a documented 11-point ergonomic design process, which has been applied to more than 265 of their hand tools since the early 1980s. The three-year process relies on user research to validate a truly ergonomic design. The process begins with a preliminary specification covering the function and working environment of the tool. Background research identifies common injuries and risk factors. Professional users test the prototypes. Results are quantified by electromyography to gauge muscle tension and a goniometer to track the user’s hands.

Prototypes are revised and tested again by more users to refine function and comfort. Pilot production tools are evaluated once again before the tool enters the market. A five-year follow-up verifies that the tool is being used properly to prevent injuries. The result of the process is an ergonomic tool with a pedigree of research, and one that makes a difference in worker injury statistics and productivity.

Let’s now take a closer look at the cases highlighted earlier.

Trimming Wires With Ergonomic Cutters
Simplex Time Recorder Company, a high-volume electronic assembly operation in Westminster, Mass., manually trimmed wire leads on circuit boards for different products using standard wire cutters. Workers performed between 600 and 2,500 operations an hour with their fingers, hands and arms. At one point, the company counted approximately 50 cases of repetitive strain injuries to their workers – tendinitis being the most common complaint. The company realized RSIs were taking a heavy toll in injury claims and lost productivity.

Consequently, Simplex initiated a new formal ergonomics program to solve their workers’ injury problems. As part of the program, Simplex worked with engineers from Lindstrom to design a cutter to alleviate stress on workers’ fingers. Through prototype research, engineers found that the new cutters would require sharpened cutting blades with rounded edges for better worker safety. Research also revealed that rounded grips would enable the user to twist the tool between thumb and index finger for the best cutting position. Extra-long handle lengths would also benefit workers. The handles could reach beyond the sensitive median nerve area on the workers’ palms to dissipate damaging hand loads.

In addition, comparative user trials and employee feedback revealed that Lindstrom’s Rx-Series ERGO cutters and pliers required another modification to provide better user comfort. To minimize the peak force for each wire cut, Lindstrom introduced an innovative Biospring. The spring opens the handles automatically, but reduces the force required to close them as the user squeezes. By the time the jaws close, the only force on the handles is that required to actually cut the wire. Additionally, the adjustable spring also allows the user to set how wide the handles open. A subsequent five-month scientific survey verified that users preferred the ergonomic tool to their previous cutters. As a result, the busy assembly operation now logs only one or two cases of suspected RSIs per year – a 25 to 1 reduction in worker injury. Also, worker comfort and productivity improved as a result of the tool switch.

Oscar Winner Goes Ergonomic
Dolby Laboratories, Brisbane, Calif., an electronics manufacturer, has been honored by the Academy of Motion Picture Arts and Sciences for its contributions to film sound technology. The company makes digital cinema processors for movie theaters. Although 90 percent of its electronic assembly operation is automated, repetitive handwork is still essential for secondary operations. Dolby’s workers used standard wire clippers to make 10,000 cuts per day (120 cuts per minute) when repairing damaged circuit boards.

However, the company discovered that electronic assembly workers elsewhere had suffered expensive injuries, including debilitating Carpal Tunnel Syndrome, when doing similar repetitive handwork. To prevent injuries in its own operation, Dolby’s tool team worked with engineers from Lindstrom to design new ergonomic cutters and pliers for workers. The ergonomic hand tools needed to alleviate stress on workers’ palms and also fit a predominantly female workforce with relatively small hands.

Dolby’s tool team evaluated six ergonomic prototype cutters and pliers to examine their different handle configurations. Prototype research revealed that the cutters and pliers required wide, slightly rounded grips to distribute forces better over a wider area than conventional grips. They also required extra-long handles to reach beyond the sensitive median nerve area to dissipate damaging hand loads. In addition, to minimize the peak force for each cut, they also required a Biospring mechanism.

After testing, Dolby standardized the Rx-Series ERGO cutters and pliers for all its workers. As in the previous case, a subsequent five-month scientific survey also found that the users preferred the new ergonomic tools to previous clippers. Since the ergonomic cutters and pliers were issued to its workers, the company has reported no new cases of RSIs.

"The bottom line is, you get what you pay for," says Marie Davies, Dolby production manager. "We looked for better tools and got what we paid for. We also made our workforce safer and more comfortable, which led to improved productivity."

Conclusion
The experiences of these two hand tool-intensive operations prove that genuine ergonomic design can lead to many advances in worker comfort, safety and productivity. And the ergonomic field is still improving.

Here’s just a glimpse of some of the more recent ergonomic developments:

• Anti-friction coatings on handsaws help cut wood with up to 77 percent less force than is required with uncoated saws.

• V-shaped handle transitions on second-generation ergonomic screwdrivers facilitate intricate work using the fingertips.

• Thick, wide handles on adjustable wrenches enable users to apply two to three times the torque available from conventional wrenches without pain.

Genuine ergonomic tools are expensive, but they payoff by reducing the risk of both direct and long-term injury to workers, thus improving overall productivity.

Article provided by Bahco Tools Inc.

MRO Today. Copyright, 2001.