Ergonomics of Garden Tools and Equipment

Richard L. Parish, PhD, PE

Factors such as price, performance, and durability are important considerations in choosing garden tools and power equipment, but if a tool or machine is uncomfortable or awkward to use, you will regret buying it. The interaction between you and the tool or machine is called ergonomics.

Ergonomics: “Ergonomics is the application of scientific information concerning humans to the design of objects, systems and environment for human use. Ergonomics incorporates elements from many subjects including anatomy, physiology, psychology and design. Ergonomists apply their diverse knowledge to ensure that products and environments are comfortable, safe and efficient for people to use. Ergonomic design is a way of considering design options to ensure that people's capabilities and limitations are taken into account.” (from The Ergonomics Society website)

Another way of looking at this is that a tool or machine should fit you and be natural to use; you shouldn’t have to adapt to the tool or machine, or be uncomfortable using it.

Examples of Ergonomic Problems:

Some rotary tillers for gardens have an operator presence control on only one handle. If the operator wants to walk along the other side of the tiller path (to avoid footprints in the newly tilled ground) he must reach all the way across the tiller to hold onto the handle with the control.
Some string trimmers have triggers that force the operator’s hand into an awkward position and cause excessive stress to the hand and wrist.
Some garden tractors and tillers are difficult or awkward to shift.
Some rotary tiller handles are too low (even when adjusted to their highest position), thus causing the operator to bend over while using the tiller.
Some rotary tillers can be tilted forward for servicing the blades; others won’t stay tilted unless they are blocked in position.
On some hydrostatic garden tractors and mowers, it is necessary to let off on both pedals to stop, whereas anyone who has driven an automobile is conditioned to step on a pedal to stop.

These are all examples of ergonomic problems. Some of these problems continue as long as you use the tool or machine, others become less of a concern as the operator learns to accommodate them. Ideally, the operator should not have to learn to accommodate the machine; the machine should be designed to accommodate the operator.

Examples of Good Ergonomics:

The differential lock on some tractors is disengaged by tapping the brake. This is a good example of designing a system so that the natural, instinctive reaction has the desired consequence.
The operating levers on ZTR mowers operate instinctively and soon become natural.
PTO clutch switches that are disengaged by merely tapping them.
Seats and steering wheels that adjust to fit the operator.
Hand tools such as rakes and hoes with foam-covered handles.
String trimmers that balance around the handle so that the natural position is the correct operating position.
Padded handles on pruning shears.
Straps on back-pack sprayers that are easily tightened by merely pulling on the ends after the sprayer is on one’s back.
A fertilizer spreader designed to automatically shut off when stopped so that the operator does not have to remember to shut it off.

Considering Ergonomics in Your Purchases: Probably the best way to evaluate the ergonomics of a tool or machine is to spend some time operating it. Even then, some ergonomic problems will not show up immediately. For instance, the string trimmer wrist strain problem noted above is not noticed until the tool has been used for 15-30 minutes. It is seldom possible to operate a new tool or machine for a significant length of time before purchasing. An alternative is to talk to other owners and discuss their experiences using the equipment. Even if you can’t operate the equipment prior to sale, at least handle it and try all the controls to be sure they are comfortable for you. If they aren’t comfortable initially, they will probably feel worse after substantial use.

Ergonomics is valid concern when purchasing a tool or piece of power equipment. Many manufacturers work hard to provide good ergonomics; others do not. If you plan to use a tool or machine for hard work, you want it to be comfortable and efficient to use. Most of all, you want a tool that fits you, not a tool that you have to adapt to.