By Jennifer Anderson
4/26/2006
No one would describe home gardeners as daredevils, but they flirt with danger from April through September every year. Musculoskeletal disorders (MSDs) lurk at every turn in the garden path – and not only for reckless gardeners. The risks are ubiquitous, but they are increasingly preventable. More makers are designing tools that remove the inevitability of gardening aches and pains.
The maximum-effect-with-minimum-effort principle underpins their thinking. Several tool makers put it to work in designs for disabled and elderly enthusiasts. One of these companies argues that solutions for the handicapped are just as effective for the non-handicapped.
OXO has built an empire on ergonomics. Best known globally for can openers and a host of other household implements, the United States maker moved recently into the world’s back and front yards with its Gel-e and Good Grips product lines.
The empire of Peta (UK) Ltd is more specialized. Its Easi-Grip® brand is designed for physically-disabled adults and children, but the company stresses the brand delivers ergonomic benefits to gardeners of all ages and abilities.
Radius™ Garden could be on the first rung of an ergonomics empire devoted to garden tools. Founded by Bruce Baker, who describes himself as a lifelong gardener and software entrepreneur, the US company produces four small hand tools and plans to introduce mid-length and long-handled tools shortly.
The Ames and Fiskar companies in the United States built large empires on standard garden tool designs, then branched into ergonomic lines in response to consumer interest.
Felco is no less an empire, though it produces only garden shears, saws and cutters. The Swiss company’s catalog suggests ergonomics isn’t a corporate interest, but the language may be misleading. The models it labels “high performance” feature details that show a keen awareness of ergonomics.
Other companies are building their empires on products that address single or grouped ergonomic factors.
Ergonomics Guidelines
In the absence of published information about specific biomechanical considerations and design issues related to garden tools, designers rely mainly on guidelines established for hand tools in general. “Hand Tool Design,” written by Dr. Alan Hedge in August 2005 and published by the Human Factors and Ergonomics Laboratory at Cornell University, is among the best-known reference works.
For this issue of The Ergonomics Report™ the Cornell paper was put to work as a “prism” for looking at several garden hand tools marketed as “ergonomic.”
In general, catalog details suggest designers have paid close attention to issues related to extension, flexion and deviation. The most comprehensive designs include padding, shock absorption and non-slip materials in the handles, and they manifest biomechanical considerations that improve usability and safety. And some designers have built cognitive aids into the tools.
OXO has taken the comprehensive approach. A gel material in the soft, non-slip handle gives the Gel-e line its name. The gel flexes to cushion gardeners who are digging into tough and compacted soil. The weeder in the same line features a triangular fulcrum for leverage and a sharpened scraper for cutting weeds below the surface. The trowels feature easy-to-read measurements for planting seeds at the recommended depth, and the serrated edges double as a bag opener and root cutter.
Ames describes its Ergo Pruner as “revolutionary” and 40 per cent easier to use than rival products. With liberal use of exclamation marks, Ames ascribes this superiority to the “Zero Friction blade coating and reverse pivot handle.” The pivot at the bottom of the handle allows a gardener to use the strongest fingers to close the tool, according to the catalog, and places the hand in a natural position for cutting flowers or trimming branches.
Fiskar mentions ergonomics in a general way and provides considerable information on the principles of ergonomics on its product website. It doesn’t list features on individual tools that illuminate or support the claim. But its PowerGear pruners were awarded an “Ease of Use” commendation from The Arthritis Foundation®, suggesting the ergonomics association isn’t spurious.
Felco, with no apparent emphasis on ergonomics, appears to devote particular attention to usability and safety issues. It produces pruners to suit almost every purpose, and accommodates several different types of user. The Felco 8, the only model labeled "ergonomic," features a “cutting head offset to extend the forearm to provide optimum pruning efficiency, handles with rubber shock-absorber and cushion to protect the wrist, a toothed centre-nut for aligning the cutting and anvil blades easily and precisely for a clean, accurate cut.” Several of its designated “high performance” pruners have a revolving handle to “spread the muscular effort over all five fingers, reducing the cutting effort by 30 per cent.” It also has models for small hands and left-handed users.
The Radius™ Garden company developed and manufactures two trowels, a weeder and a cultivator in its range of Natural Radius Grip™ hand tools. The NRG grip, pronounced "energy" grip, is as unusual for its downward bow shape as it is for the color – a chartreuse green that glows in the light. The tools “maximize power and comfort while minimizing hand and wrist stress,” according to the catalog, transferring energy from large muscles directly to blades and supporting a wrist-neutral position. And the handles are made with Santoprene™, described as a non-latex thermoplastic designed for high performance, comfort and a secure grip, wet or dry.
The Ergonomics Report™ asked founder Bruce Baker what ergonomics criteria his team considered when designing the NRG line.
“Our main goals were to build a tool that would ‘encourage’ as opposed to ‘force’ one to deliver thrusting or pulling force with a relaxed hand and neutral wrist,” he replied. “Our belief was that gardeners do not like restrictions on movement, but will naturally use a better designed tool in a safer, sounder way. In fact, since the word ‘ergonomic’ derives from the Latin words for ‘work’ and ‘natural’, our goal was to design tools that would work more naturally with the hand and wrist than the traditional straight-handled tools.”
Industrial designer Jan-Henrik Andersen was consulted on the NRG project, and the company relied on their own field and feel testing. Baker explained that their “extensive research” covered the physical structure of the forearm, wrist and hand; the ergonomics of gripping and at the same time delivering a pushing or pulling force; common stress conditions of the hand, wrist, and forearm; and common uses of small garden tools.
The curvature of the palm in the area of the lifeline provided some of the inspiration for the distinctive bow shape of the handles. “It describes part of a circle,” Baker said. “We used this as a guide in constructing a semi-circular grip to accommodate a large ‘angle of attack.’”
A study of martial arts led to an understanding of how the maximum thrusting or pulling force could be obtained. “This led us to the conclusion that pulling or thrusting energy is most effective when it is concentrated in an imaginary line through the forearm, parallel to the radius and ulna bones, extending through the butt of the hand and fist. We extended this line to the working tip of the tool blades, spending a great deal of time on each tool making sure it was possible to loosely grip a tool from the back of the grip with this alignment. That is why the angle of each blade is slight different from each other.”
Age Limitations and Disability
A passion for gardening often arrives with retirement and the time to pursue hobbies, and ageing often introduces physical limitations. Gardening is often an attractive hobby for disabled people. The two groups are the focus of several makers.
Peta designs for gardeners with impaired hand and wrist function, but stresses the special features of its tools benefit users of all abilities. The distinctive yellow handles of the company’s Easi-Grip® line are set at right-angles to the blade or fork “to keep hands and wrists in a natural position,” according to Peta’s catalog, and the “soft feel, non-slip grip prevents tools from turning in the hand.”
For users with arthritis or particularly weak hands and wrists, Peta markets an arm support cuff that plugs into the rear of any Easi-Grip tool to utilize the strength of the forearm.
Tools - Never Lost for Long
Many gardeners know the frustration of mislaying hand tools. A feature that makes them stand out in long grass or under shrubs can count on applause from distracted gardeners, winning points for ergonomics at the same time. OXO does it with the blue gel discs at the sides of handle, a feature that distinguishes tools in the Gel-e line. The discs are bright enough to be spotted easily. Radius™ Garden does it with almost-blinding chartreuse green, the color of the whole handle.
Auxiliaries and Extras
Spades, rakes and other long handled tools spell trouble for users if they are carelessly used or poorly designed.
Cornell’s guidelines say, “Bulky objects should have two handles.” It’s advice that appears to have been heeded by the unidentifiable maker of the Wrist Easy line of tools. The trowel has a curled handle at the end and a stump handle in the middle of the shaft, designed, according to the catalog, “to keep your arm straight while you dig, reducing strain on your joints and wrist … The arm pad provides comfortable support for your forearm, giving you good leverage without constantly requiring you to bend your wrist and arm.”
Motus’ second handle is an accessory for the long-handled garden tools on the market. The D-grip handle mounts mid-way down a long handle, giving lifting leverage to the forward hand. The T-grip handle mounts at the upper end, giving pushing and pulling control to the back hand. “In combination, they optimize their mechanical advantage,” according to the Motus catalog.
The Ergonomics Report™asked Motus representative Greg Klassen to explain the idea behind the two accessories. “The T-grip was originally developed to emulate our grandfather’s scythe,” he replied. “(It) was a natural progression from the same principles to make garden tools easier and safer to work with.”
Klassen said Dr. Dean Kriellars at the University of Manitoba’s Faculty of Medicine School of Medical Rehabilitation, evaluated the grips. “The hand-hold permits the wrist angle to remain in a near neutral position in the ulnar/radial plane,” the scientist said, and “ulnar deviation is limited to a maximum of 10 degrees as compared to 35 degrees without the use of the grip.” He described the grip as beneficial to the structures in and about the wrist.
The scientist found a 10 per cent reduction in load “arising from the decrease in trunk angle and the closer load.” He described the reduction as substantial for both repetitive and single execution tasks, and beneficial for the prevention and rehabilitation of low back injuries.
The grips could end the torment of blisters for energetic gardeners. The scientist attributed this potential benefit to a “reduction in the magnitude of skin surface shear.”
A Gripping Curiosity
Given the attention to grip in the sampling of garden tools in this installment of The Ergonomics Report™, it is surprising that only one maker makes specific provision for the vast difference in hand sizes among users.
Grips should be contoured to the curve of the palm of the hand, according to the Cornell guidelines, and the length and span of the grip should fit the hand. Grip spans that are too small or large reduce grip strength and stability, the guidelines state. It follows that a man-sized grip will be too big for a woman’s hand, a woman’s too small for a man’s hand and a medium-sized grip the wrong size for both.
OXO acknowledges the importance of size differences in its slogan, “Hands come in all shapes and sizes. We try to fit them all.” Yet OXO, along with the other makers, expect one size to fit all when it comes to handles. A single exception appears to be Felco. Its pruner models No. 6 and 12 are designed for small hands.
Felco also pays more attention than other makers to handedness, appearing to be alone in offering several models for left-handed gardeners. Most makers ignore lefties all together. Others accommodate them with ambidextrous features. OXO's Bypass Hand Shears has “a conveniently located locking switch … easily accessible by both lefties and righties.” Fiskar’s Swivel Grass Shear boasts an “easy-to-reach ambidextrous lock.”
How Can Ergonomic Garden Tools Be Distinguished From the Rest?
If independent evaluations of garden tools marketed as ergonomic exist, they are well hidden. How is a consumer to tell which product or feature described by the maker as ergonomic is a gimmick and which deserves the description? They may have to rely on reputable retailers to make the distinction for them. The Ergonomics Report™ asked Donald M. Swartz, principal of the online stores, Life with Ease® and Gardening with Ease®, how he does it.
“In order for us to add a new product it must first meet the criteria of seeming to accomplish the task of minimizing stress,” he explained. “Since I have a background in Engineering and Chiropractic it would be impossible for that to not influence my decision making. However, given that there is inadequate research and testing, primarily due to a lack of funding from government and industry, I also apply a good deal of common sense in determining which products I should check. Finally, I use each tool – I am 56 years old and an excellent example of someone beginning to experience pain and injury with previously non-injurious tasks.”
Swartz explained that his background makes him particularly sensitive to the need for ergonomically-designed garden implements. He said he met thousands of patients with pain or injury who didn’t want to consult doctors, preferring to take care of themselves. “I always tried to help them do this,” he added. In helping them he discovered many of the products with which he began Life with Ease®. “I included gardening tools with our product line (of vision aids and other assistive tools and devices) because I was an avid gardener.” He saw significant interest in the gardening line, and the company has since launched a sister site dedicated to ergonomic gardening products.
Radius™ Garden founder Baker warns consumers to be wary of what he calls "ergo-nonsense." “Most manufacturers use ‘ergonomic’ to describe the same old tools they've been selling for decades," he explained. "They add some bumps or contours to the handle, or make the grip fatter. But the only thing that's really different is the packaging with the word ‘ergonomic.’”
The best protection against “ergo-nonsense” is a set of guidelines on the ergonomic design of garden hand tools – one for the industry and one for consumers. It is overdue.
Sources: OXO; Peta (UK) Ltd; Fiscar; Ames; Felco; Bruce Baker; Radius™; Garden; Motus; Greg Klassen; Wrist Easy; Human Factors and Ergonomics Laboratory, Cornell University; Donald M. Swartz; Life with Ease®; Gardening with Ease®
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