Tool buyers thinking of purchasing a product may find that it is “ergonomic” or has an “ergonomic design.” Yet often there is no explanation about what makes the tool ergonomic.
For many, ergonomics is a feature added to a product’s list of capabilities, a frosting on a promotional cake. Indeed, ergonomically designed tools are set apart, but the careful buyer needs to understand the features and their benefits. Ergonomics is an applied science concerned with designing and arranging something people use so those interacting with it can do it as efficiently and safely as possible.
“To be ergonomic, at a minimum, the design of any hand tool should be able to accommodate a range of sizes of hands, from a 5th-percentile woman to a 95th-percentile man,” said Alan Hedge, professor emeritus and director of Cornell University’s Human Factors and Ergonomics Laboratory, and now a consultant. “The product should be comfortable to use, and it should not expose the user to known postural risks, such as bent hands, that increase the likelihood of a musculoskeletal injury.”
The ergonomic design of many kinds of hand tools has improved enormously in recent years, Hedge said.
“Initial work on ergonomic design focused on tools like power drills, pliers, hammers and wrenches, and the concerns focused on how well these tools fit a user’s hand and whether they increased the risk of any musculoskeletal injury to the hand or arm,” Hedge said.
There are more factors to consider.
“In addition to hand size, there also are considerations of hand strength and hand dexterity. It’s also important to think about the position of the body while the tool is being used,” Hedge said. “For example, using a simple tool like a screwdriver has very different effects on the body if the user is screwing something into the floor where the screwdriver is below the heart level, compared to screwing something into the ceiling where it is now above the user’s heart level.”
Broadly speaking, Hedge said designers have improved tool shape to fit either a bare or gloved hand, and the weight has been improved so the tool is not too heavy and likely to fall out of the hand when used.
It follows that an ergonomically designed hand tool considers size, weight and balance to be comfortable to hold in work conditions, keeps the hand in a neutral position as much as possible while force is being applied and is easy, efficient and safe to use. Designers have considered the muscles an operator will use to minimize strain when operating the tool.
For tools such as power drills, the center of gravity has shifted over the handle so the tool is easier to hold and keep in a level position.
“Many power tools have some kind of padding or vibration-absorbing component that reduces the reactive forces to the body,” he said. “Some hammers have antivibration features so when it hits an object, less force gets transferred back into your body. Even if a hand tool meets all of the above requirements, there can still be other concerns.”
For example, the criteria may exclude extreme hand sizes. It’s also assumed that the tool will be used by an able-bodied adult and not a younger or disabled person.
“With factors such as age, there are natural declines in strength and dexterity that will affect how effective that tool is. So there is no ideal ergonomic design, just as there is no ideal shoe size, and it should be possible for a person to find a tool that feels comfortable in the hand and feels relatively easy to use. Such tools are more likely to be described as ergonomic,” Hedge said.
He cited the electric drill as one of the best examples of how ergonomic design has improved a tool.
“Look at the design of a power drill 30 years ago,” he said. “Then the typical power drill had a relatively short handle that was placed at one end of the drill’s motor to the tool’s center of gravity, which meant it required more strength by the user who had to hold the drill to stop its natural rotation and falling out of the hand. These days, the center of gravity has changed because the handle of most power drills is more central to the motor and drill bit.”
Many ergonomic tool features directly and indirectly make a tool safer to operate. A lightweight, well-balanced, handheld electric drill or saw is less likely to be mishandled or dropped. An ergonomic design that reduces strain on the wrist and other muscles lessens the chance of vibration-induced white fingers, trigger finger tendinitis, carpal tunnel syndrome and other long-term physical issues.
Ergonomic tools used throughout the day are less tiring, reducing the risks of careless operation due to fatigue. Properly used, an ergonomic tool is a safer tool.
“Battery-operated tool designs often place the battery below that handle and to balance the drill so that it can stand on a flat surface. I believe that tool manufacturers are becoming more aware of the importance of good ergonomic design, and some of my own students have gone to work for tool companies to assist in ergonomic design,” Hedge said.
There are limitations, of course, because people have different strength capabilities and tool preferences. There can be no universally ergonomic design that fits every user’s needs.
“It is important that if a company designates a tool as ‘ergonomic,’ the manufacturer gives users some guidance about what that means, such as identifying the range of hand sizes that fit the tool’s design and being specific about other ergonomic features and their benefits,” he said.
Tool users need to be aware of a tool’s ergonomic features when they compare products prior to purchase.
“Today, there are electronic services readily available online to speed tool comparisons,” Hedge said. “But there really is no substitute for holding and trying a tool to know whether it is likely to be the right tool.”
As tool manufacturers employ ergonomic specialists and have ergonomic departments, and there are consultants ready to assist with ergonomic design elements.
Manufacturers meeting needs
“The Greenlee Ergolab was originally established to help define our product design in comparison with other products in the market,” said Ryan Berg, director of product management at Rockford, Ill.- based Greenlee.
“Today the Ergolab is used for a wide range of internal applications, driven by ergonomics and a constant mindset of considering how users interact with our tools and how the tools interact with their environments,” he said.
“When considering updating products in our portfolio, testing in the Ergolab can provide strong quantitative proof of how a proposed new product design concept can aid the tool user in, for example, areas like energy exertion or how body positioning can be improved.
“Long-term use of any tool is our focus. Basic ergonomic design can be immediately identifiable along with end-user feedback; however, those are the easy components to identify,” Berg said. “The Ergolab comes into play for deeper analysis and refines the more ‘hidden’ design elements that can usually only be found by software and sensor outputs that we employ at the Ergolab. That capability can take a good design and make it a great design in the realm of ergonomics.”
Production is the name of the game, and ease of tool use is a common driver for how buyers make decisions on tool purchases.
“The easier we can make a tool to use, the less the user has to worry about when actually using the tool. They can better focus on safety and their environment,” Berg said.
Most of Greenlee’s new product development processes have benefited from the Ergolab. One example is a new battery-powered wire cutter. A change in the cutting head’s design removed 33% of the tool’s weight.
Is there a point when a tool can reach efficiency and ergonomic perfection? When there are no more improvements to be made?
“There are diminishing returns at a certain point,” Berg said. “Optimally balancing ergonomics, safety, ease of use and tool reliability is really what we are shooting for.”
Troy Marks, group manager, product marketing at Milwaukee Tool, said: “Everyone agrees: Workers need to return home just as healthy as when they reported for work. We work closely with our end-users to better understand the problems that they’re facing and help design solutions to solve those problems. Ergonomics is no different. We are always learning of constant pain-points regarding existing tools in the market. We are dedicated to finding the root of the problem and creating solutions that will make contractors’ jobs safer and easier.
“At Milwaukee Tool, we believe that ergonomics begin in the design phase of our development process—when that tool is just an idea on a piece of paper. For example, users are often dealing with 5- or 6-lb. handheld tools that they need to hold for extended periods of time. The goal is to create a balanced tool that will decrease muscle effort, and we want to prove that, objectively, before the product gets too far along in the process and it’s too late to make changes to the tool.” —J.G.
About The Author
GRIFFIN, a construction journalist from Oklahoma City, can be reached at [email protected].