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A hard day's work on-site is tiring enough. Contributing discomfort from the use of a wire cutter or power drill begs a solution. It’s called “tool fatigue” and efforts to remediate it are ongoing. Its progress is evolutionary with a few revolutionary breakthroughs.
Studies are evaluating how workers use tools and how these tools impact their bodies. Tool manufacturers are using research and development to deliver products that address fatigue. In its ergonomic research, the scientific community is providing insight into hand and power tool use.
To date, advances have made hand tools more ergonomic, power tools cordless with less operational vibration, and tool foot-prints smaller and lighter. Mark Herman is the national product manager for Graybar Electric Co. Inc. in St. Louis, an electrical products distribution firm. He sees firsthand what manufacturers are doing to reduce tool fatigue for contractors.
“Tool use had always been very personal, and good tools are perceived as those that fit well for the user,” Herman said. “Weight, twisting and torque, grip, and squeezing in repetitive motions weren’t previously being taken into consideration in tool design. Products were needed that could counter such effects and improve the effectiveness and efficiency of the tool itself.”
“You migrate to a hand tool that fits well,” Herman said. “If it isn’t comfortable, the fit may be wrong, the balance may be off, or you may not be using good form. The same is often true with power tools. In addition, electrical contractors are not in one position all day. They are reaching above their heads, on their knees or stretching to reach a crawl space. Effective tool design needs to offer good weight, balance and a good handle. Power, torque, battery life and portability are also important.”
Today, Herman sees a number of manufacturers making great strides. Companies, such as DeWalt, Greenlee, Ideal, Klein and Milwau-kee, consider how you hold a device and its overall functionality, including efficiency and tool life; these companies ultimately wish to pro-duce a product that doesn’t work against the end-user.
“A tool manufacturer’s goal is to create a product that makes the job easier,” said Steve Ratkovich, manager of training and special projects for Klein Tools Inc., Lincolnwood, Ill. Klein has been designing and manufacturing hand tools since 1857.
“Good hand tool design involves two objectives: delivering performance and comfort,” Ratkovich said. “A screwdriver without a good tip can spoil the work. An awkward or uncomfortable tool is a problem as well. Either contributes to fatigue, perhaps even repeti-tive motion issues. They also slow you down.”
Ratkovich cited two examples of tool evolution.
“Lineman’s pliers are typically used to cut, bend, shape or pull wire. When the tool closes and cuts, a ‘snap’ goes to your wrist. We tempered the handle, so it had some give. We then twice hardened the cutting blade, and so the snap was diminished. We looked at fish tape, as well. The case was redesigned in several ways. It’s now bigger (13-in. diameter) to reduce tape revolutions and features a sloped handle for quick hand-over-hand rewinds.”
He added that, though an electrician’s work may grow in complexity, tool use still revolves around comfort and motion.
“For core hand tools, redesign is a continuous process,” Ratkovich said.
Mark Hickok is manager of product safety and regulatory compliance for Milwaukee Electric Tool Corp., Brookfield, Wis. Mil-waukee opened its doors in 1924. Like Klein and others, the “voice of the customer” helps direct product refinements.
“We develop prototypes and place samples in customer’s hands for feedback,” Hickok said. “We look at everything from hand positioning and wrist angle to vibration and balance.”
Milwaukee’s new M12 and M18 lithium-ion lines of power tools represents its most recent refinements. Hickok pointed to two product examples.
“The design of our M12 Hackzall evolved a great deal based on user feedback. We reduced it in size, weight and made it cordless,” he said.
The reciprocating saw can be operated with one hand to get into tight spaces and make accurate cuts.
“Our M12 copper tubing cutter developed out of a contractor need to find a way to cut pipe more efficiently with less hand and wrist fatigue,” Hickok said. “The new cutter replaces a repetitive, manual operation with a powered solution adding speed and less cutting steps.”
Hickok agreed that tool advancements are often a matter of refinement.
“Breakthrough technology, like lithium-ion batteries or advancements in motors, occurs once in a decade. In the near term, electrical test and measurement devices are the latest tools to address ergonomically and extend battery life,” Hickok said.
A contractor’s contribution to fatigue
Martin Cherniack is a professor of medicine and director of the Ergonomics Technology Center (ErgoCenter), a joint venture of the State of Connecticut and the University of Connecticut Health Center in Farmington, Conn. He regularly invites skilled craftsman to study and observe how they use and handle tools. The center’s research raises an intriguing question.
“If you optimize the ergonomics of a tool, would you change the way people work? We don’t know. What we do know is that if you take ergonomic and nonergonomic tools and use them in sequence, the individual’s use dominates over tool design. And yet through training, you can fundamentally change user behavior to correct tool use,” he said.
Cherniack cited different types of fatigue.
“If you are working at a static position and arms raised, that will create fatigue due to circulation. So will standing on your feet all day. Then there are issues with the impact of power tools and nonpower tools where the nervous system has to adapt. Nerve receptors may slow down creating dullness of perception based on the energy of the tool. Error rates tend to go up towards the end the day. This is an-other kind of fatigue. Recognizing what causes fatigue enables a tradesman to remediate their actions during the day and directs manufac-turers’ designs.”
He would like to see some standardization in hand tools.
“You can’t generalize everything, especially in ergonomics, but there are areas you can tackle,” Cherniack said. “In nonpower tools we can talk about the center of mass of the tool, where you hold it so it’s maximally effective, position of the hand and the handles, trigger and force, angularity to equalize pressure, play in the hand, the amount of energy back into the hand, and torque of the tool. Power tools offer more options with specs, such as hand/arm vibration and the elimination of it. You look at frequency, range, then isolate and filter it out.”
Cherniack pointed to the European Union, which has a power tool directive mandating the elimination of vibration or sufficient protection from it. U.S. power tool manufacturers with global markets find the advances made in Europe benefit them domestically, as well.
“I think if a requirement improves safety, regardless of where it comes from, it is in everyone’s favor,” Hickok said. “Milwaukee has taken an active role in efforts to harmonize power tool safety standards in the U.S. with those in the E.U. This can simplify product devel-opment and encourages consistency in safety approvals, which is a great benefit to the manufacturer, the test labs and the end-users.”
Graybar’s Herman offered these tool and contractor safety tips.
“Use the right tool for the right application,” he said. “Choosing pliers when you should be using a wire cutter will damage hand ligaments. If you are applying an underpowered tool for the job, no amount of ergonomics will help you. Applying too much force on the tool does not benefit your body or the work. In addition, using the wrong size shaft or drill bit can create a seriously out-of-balance tool.”
Safety is an added concern.
“While it’s fatiguing when you overreach or work off balance with a power tool, such ‘short cuts’ can also cause accidents,” Hickok said. “Use common sense and don’t ignore a manufacturer’s warnings and instructions.”
Herman said a tool should be properly insulated, as well.
Contractors have seen and should expect to see increasing advancements in hand and power tools. Reducing worker fatigue is an added criterion to defining tool quality and performance.
GAVIN is the owner of Gavo Communications, a marketing services firm serving the construction, landscaping and related design industries.He can be reached at [email protected].