Ergonomics: Think about it

April 1, 2004

Safety Matters

Think about it

By Emily Refermat

There are many things to consider when working on an aircraft. You have to determine what needs to be done, how you are going to do it, what regulations and ADs apply, and the necessary safety precautions — all before you actually perform the maintenance. While concentrating on the job at hand there might be something you’re forgetting — your body.

Airtool swivel allows the operator to better position the tool without fighting the hose.
Turntable for grinding parts; supports the part and allows the operator to rotate the part 360 degrees while working on it.

Ergonomics, human engineering, repetitive motion/muscular stress studies, or whatever you want to call it, the interaction between the human body and physical work is an important topic for mechanics and employers to consider.

Maintain ergonomic safety
There are many things you can do to keep your body safe from ergonomic injury. The first and foremost is to listen to your body. Be conscious of how your body is positioned. Are you crouching over your work? Is every muscle in your neck and back tense and under strain? Does your wrist hurt after working your shift? These are clues that you could improve your work practices.

Adjust stool or table heights when you can. If possible, try to avoid moving heavy objects to varying heights. For example, if you are maintaining a battery or starter generator, use an adjustable cart that can move up or down to be as near the bench height as possible (and also near the height you need to put it back in the aircraft). This will reduce the body strain of lifting, adjusting the body, and putting the heavy object down. Remember to lift with your legs, rather than your sensitive lower back. Avoid twisting your upper body while lifting heavy objects. Try using hoists or asking for help when lifting and moving heavy or bulky objects. A back brace is also a good idea.

Vary tasks throughout the day. This may take a little planning, but think about the jobs that you have to do. If the first requires you to sit or squat for a long time, do a job standing up afterwards, to stretch your legs and use different muscles. Walk around and stretch shoulders, back, legs, and even your neck during frequent breaks. This not only allows your muscles a respite from the motion you have been using, but can also refresh you, making it easier to concentrate on your task.

Don’t forget eyestrain. If you are working with wiring or intricate material up-close for a long time, refocus your eyes on something distant for awhile. Or close your eyes and place the palms of your hands on your eye sockets.

Use the largest muscle possible. If you’re torquing down a nut, for example, use your whole arm to rotate it with a ratchet instead of twisting it with your fingers. The large muscles of your biceps and triceps will be able to handle repetitive motion better than the smaller muscles and tendons of your fingers and wrists.

Exercising and eating right will also help keep you safe from ergonomic injury. Exercise maintains muscle tone, increases circulation and oxygen flow, and improves other areas of health such as mental acuity, heart, lungs, mood, and lowers stress.

Taking an active role
As part of being conscious about what you’re doing, how you are standing, what tools you decide to use, etc. also look at the process you are using. Could it be done faster? Safer?

At Pratt & Whitney Canada Component Repairs in Wichita Falls, Texas (P&WC Wichita Falls), an ergonomics committee consisting of 10 employees from all levels in the plant work on ergonomics from a safety counsel perspective, says Judy Roberts, human resource manager at the facility and leader of the ergonomics subcommittee. The committee is dedicated to surveying employees about ergonomics and putting improvements into effect.

There is an initial assessment of any new job, says Tony Gallagher EH&S (Environment, Health, & Safety) and ACE coordinator at P&WC Wichita Falls, as well as a process of reassessment called “Design Process Review.” “Anytime a process is changed or a new piece of equipment is brought into the facility, the assessment is reaccomplished and updated,” Gallagher says. The process is both proactive and reactive in establishing ergonomic guidelines.

In 2002 Pratt & Whitney US initiated a worldwide Frugal Ergonomics Contest. Employees from the Wichita Falls facility entered the contest and won first and third places. In 2003, Wichita Falls repeated with first and third places in the worldwide contest. Roberts says these wins are a tribute to the individual creativeness and innovative approach to ergonomics exhibited by the Wichita Falls employees. “The intention is to engage employees in coming up with ergonomic improvements that make their jobs safer, easier, and protected,” says Bill Eyster, general manager at the P&WC Wichita Falls.

During 2003, P&WC Wichita Falls was proud to be awarded VPP (voluntary protection program) Star status, a prestigious recognition from OSHA based on at least three years of superior safety records. In conjunction with the Star recognition, OSHA also recognized Wichita Falls with Best Practices in both ergonomics and employee involvement.

Putting it together
Awareness of body position, knowledge of the ergonomic features of your tools and shop equipment, as well as getting involved with job processes can lead you and your company to a safer and more productive environment. At both LINK Tools (see sidebar) and P&WC Component Repairs (Wichita Falls) the increase in worker safety has also led to increased productivity, not to mention that more ergonomically friendly work practices will lead to less employee injury and workers’ compensation claims. Ergonomics can truly be a win-win situation.

Making your job easier Companies often take into account ergonomics when designing tools — pliers with molded plastic handles that fit your fingers, drills with a textured handle for a better grip, rivet guns with extra padding, etc. Ergonomic tool accessories are also available, like gloves with gel inserts in the palm to help reduce the impact of vibration during riveting operations. LINK Tools has a set of products that John Davidson, president, says have a feature of overwhelming importance for ergonomics — “hand-to-work” locking. For years sockets were “retained on the end by a spring-loaded ball bearing.” If your hands were greasy the socket was hard to remove and if the spring got dirty, the connection would be so weak that the socket would fall off, says Davidson. It was Pete Roberts who came up with a better socket release — the Quick Release for ratchet wrenches — sold by Craftsmen in the late ’50s/early ’60s. Not satisfied with his invention, however, Roberts went back to improve his design. “He came up with a totally revolutionary approach … he put a diagonal pin through the shaft of the tools, which comes out inside the socket. The top of the pin comes out above the head of the socket and can be quick-released at any connection by pulling up on the ribbed collar that goes around above where the socket goes. And as a result the pin now retains, from the inside, the socket,” explains Davidson. Since the pin is diagonal, putting stress on the pin wedges it into the socket. It is locked until the quick-release releases “the top end of it. It withdraws from the socket and allows it to release.” The design revolutionized not just ratchet wrenches, but all related hand tools, says Davidson. Roberts developed a comprehensive system that locks all tools and exisitng socket pieces together, from the user’s hand to the work, and also allows every connection to be quick-released apart — the LINK’s new Quick-Lock technology. TÜV Rheinland of North America, a member of the TÜV Rheinland Group (a global leader in independent testing and assessment services) tested the LINK Tool Quick-Lock Tool System and awarded it the Q-mark as well as certifying the improvement in productivity and reduction in physical stress, strain, and fatigue. An excerpt from the TÜV study summary: “The user test confirmed an improvement in impact on the body specifically in the amount of bending and stretching required during use resulting in reduced strain, stiffness, and pain. Specifically test participants with muscle-skeletal problems experienced significant reduced strain, stiffness, and pain.” Davidson says most professional mechanics use extensions on their tools, and these tools have a tendency to fall apart at the connections, falling into the aircraft. Mechanics, therefore, crouch over their work, ready to catch the pieces if they fall from the tool. This leads to stress on the mechanics’ muscles and skeleton. With the locking tools, however, mechanics don’t have that problem. During the study mechanics reported: “Being an aircraft mechanic, I have to reach into, over, and under areas that I cannot afford to lose a socket. The ability of [the] LINK brand to lock onto the socket is huge.” Indicating a 75 percent reduction in lost days due to the pain associated with physical stress: “I contribute the most of this to the fact that I have been able to do work standing or sitting in positions somewhat normal [using the LINK Tool system, and] not twisting or contorting my body in ways I used to have to reach a part I was trying to work on, or trying to keep sockets, extensions, etc. attached to my ratchet or whatever I was using.”

Additional ReSources
LINK Tools

TUVdotcom ID 2835704000

Pratt & Whitney Canada