Distributed 7/25/03

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’ll regret buying it, according to LSU AgCenter engineer Dr. Richard Parish.

"The interaction between you and the tool or machine is called ergonomics," the LSU AgCenter’s Hammond Research Station engineer says.

The Ergonomics Society explains that ergonomics is using what we know about humans to design the objects, systems and environments people use. Ergonomic design considers options to be sure people's capabilities and limitations are taken into account.

More simply put, Parish says, 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.

Parish cites several examples of shortcomings of lawn and garden tools and equipment:

• Rotary garden tillers that have a control on only one handle so the operator must stretch across the tiller to reach the control if he wants to walk along the opposite side to avoid footprints in the newly tilled ground.

• String trimmers with triggers that force the operator’s hand into an awkward position and cause excessive stress to the hand and wrist.

• Garden tractors and tillers that are difficult or awkward to shift.

• Rotary tiller handles that are too low (even when adjusted to their highest position) and cause the operator to bend over.

• Rotary tillers that won’t stay tilted for servicing unless they are blocked in position.

• Hydrostatic garden tractors and mowers that are stopped by letting off on both pedals instead of pushing them as anyone who has driven an automobile is conditioned to do.

"These are all examples of ergonomic problems," Parish says. Some of them continue as long as you use the tool or machine. Others become less of a concern as you learn to accommodate them.

"Ideally, the operator should not have to learn to accommodate the machine," Parish says, explaining, "The machine should be designed to accommodate the operator."

The engineer also points out examples of good ergonomics:

• On some tractors the differential lock 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," Parish says.
  
  
• The levers on zero-turning-radius mowers operate instinctively and soon become natural.
  
  
• Power take-off 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.
  
  
• Back-pack sprayers with straps that are easily tightened by pulling on the ends after the sprayer is on your back
  
  
• A fertilizer spreader designed to shut off automatically when it’s stopped so the operator doesn’t have to remember to shut it off.

Parish suggests a good way to evaluate the ergonomics of a tool or machine is to spend some time operating it. Even then, however, some ergonomic problems won’t show up immediately. For instance, you may not notice the string trimmer wrist-strain problem until you’ve used the tool for 15-30 minutes.

"It’s seldom possible to operate a new tool or machine for a significant length of time before purchasing it," Parish says. 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’re comfortable for you," Parish says. "If they aren’t comfortable initially, they’ll probably feel worse after substantial use."

The engineer says ergonomics is a valid concern when purchasing a tool or piece of power equipment.

"Many manufacturers work hard to provide good ergonomics," Parish says. "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."

Parish also recommends contacting an extension agent in your parish LSU AgCenter office to learn more about ergonomic tools. In addition, look for Gardening and Get It Growing links in the Feature section of the LSU AgCenter Web site