The art of erognomics >By Mark Michaels, Husqvarna Forest & Garden Co.
Making a special effort to enhance your personal environment is one of the smartest things you can do. When grounds managers don't, all too often accidents or injuries occur, in addition to losses in productivity and profits. If you learn one thing in this business, it is to take the steps necessary to protect yourself from physical harm. Even so, many turf and landscape supervisors place too little importance on the role of ergonomics in safety and how they can minimize accidents and chronic medical problems. In the grounds-maintenance business, ergonomics ultimately boils down to a discussion about equipment and apparel. Before you make your next purchase, develop a better understanding of what ergonomic characteristics you should consider. In doing so, you'll ensure a safer work environment for you and your crew.
Purchase equipment with personal comfort in mind You should consider several factors about ergonomics before making a purchase. Most specifically, give some special thought to your individual needs, your physical comfort and engine-emission levels.
* Your needs. Before purchasing any equipment, focus on your specific needs. Will you use the equipment on a continual basis, and if so, under what conditions and for what purpose? Nothing encourages fatigue-and accidents-more than using an inappropriately heavy piece of equipment. With luck, of course, you hope the backaches and sore arms will end after a few days, but what about the potential for more serious, chronic spinal and nerve damage? To address this, look for equipment that provides the highest power-to-weight ratio. This is not as easy as it may seem. Yes, perhaps the equipment is light enough to handle, but does it provide enough power to accomplish all the tasks for which you need it? And, will the type and duration of tasks change over time? If so, will the power-to-weight ratio remain appropriate? Is it adjustable for the many different employees that may use it? Answer all of these questions before putting your money on the counter.
* Physical comfort. To minimize fatigue-as well as ailments such as back strain, white-knuckle disease and carpal tunnel syndrome-pay attention to the level of physical comfort you experience when using the equipment. If you don't have a high level of comfort, don't make the purchase.
Vibration and noise levels are closely related to comfort. Ergonomically advanced equipment, including many of today's chain saws, trimmers, brushcutters and blowers, fight vibration and fatigue with anti-vibration systems. These systems separate the engine from the handles. Let's look at some specifics to give you a better idea of what we mean.
* Chain saws. When purchasing chain saws, look for angled handles, slim bodies with few protuberances and lightweight parts with a high center of gravity. Such aspects allow you to work with the saw close to your body, which reduces back strain and minimizes uncomfortable working positions.
Remember, too, that chain-saw bar length affects its balance. A shorter bar creates a neutral center of gravity and a lighter saw, while a longer bar moves the center of gravity slightly forward and adds weight. Normally, you'll get the best performance with the lightest saws and shortest bars possible to handle the needs of a given job. Saws with continuous top covers without gaps between the cylinder and carburetor reduce the noise directed back at the operator.
* Hand-held blowers. The most ergonomically friendly designs of hand-held blowers lift slightly while running, due to the force of air blowing. This lift creates a wrist angle that promotes comfort. Another ergonomic perk is a handle that's in line with the blower tube. This type of design reduces wrist strain and provides better maneuverability than a blower with a handle off-set from the tube. If you have a crew with both right-handed and left-handed members, purchase a blower that groups the starting and operating controls together, as well as having a front-exhaust engine. This feature steers fumes and engine noise away from the operator.
* Backpack blowers. A comfortable addition to backpack blowers are pistol-grip handles that are attached to the mounts of the blowers. This configuration not only allows you to change speeds more easily, but it yields better control. These types of advancements also enable you to operate blowers for longer periods and with less fatigue.
Advancements in backpack blowers include designs that reduce noise and use more comfortable harness designs. Look for mufflers that provide both high capacity and high volume to reduce noise. And don't forget hearing protectors (see subhead on page 17, "Apparel can increase comfort, too"). Choose those that list a noise-reduction rating (NRR) of 22 dBa or better.
It's a good idea to check with local authorities before purchasing blowers, because many communities have ordinances that restrict the use of those louder than certain decibel levels (see related article, "Equipment Options: Backpack and walk-behind blowers," June 1998). This especially is the case with backpack blowers, which have higher air velocity and power, and therefore create more noise. You can expect additional advancements in noise-reduction designs in the future.
* Emissions. The Environmental Protection Agency also has implemented stricter emissions standards for equipment of all sizes. And many states are expected to modify these statues or implement additional ones. In response to such legislation, most hand-held power-equipment manufacturers have engineered cleaner burning engines on their latest product offerings. Some have gone as far as redesigning their 2-cycle engines to improve air/fuel mixing and combustion efficiency. Some recent advancements include engines incorporating catalytic converters, as well as low-emission engines. Such systems are advantageous because they emit less combined hydrocarbon and nitrogen oxide emissions, as well as less smoke and odor.
You also can cut emissions by using oil and lubricants that reduce smoke and fuel oxidation.
Apparel can increase comfort, too In recent years, several manufacturers have introduced new apparel designed with help from ergonomic experts. One example is apparel for arborists with specially designed boots, bib-style protective pants and protective shirts. Features on these clothing items include flat shoe soles for foot-locking during climbing, articulated pant knees for reduced pull when bent, and improved maneuverability and lightweight mesh bodies on protective shirts for cool comfort. In addition, bib-style protective pants often are now designed to keep climbing belts, harnesses and suspenders out of the way. This allows you to use shoulder straps that are easy to adjust for comfort, as well as easy access to side panels. (See related article, "What's New: Personal protective equipment," Grounds Maintenance, November 1997.)
* Eye wear. When on the prowl for protective gear, make eye wear a priority. Look for eye glasses that provide the widest range of vision while meeting ANSI Z87.1 regulations. The ANSI stamp on the glasses is a statement of eyeglass quality and shows they've passed impact-resistance tests. If you or your crew members need sunglasses, look for a linear frame design and a sweeping, curved lens for an uninterrupted field of vision. Also important is a flexible nylon frame that adapts to facial contours.
* Ear wear. You'll find a full range of protective ear wear, much of which is task-specific. For example, most grounds-maintenance professionals can safely opt for simple ear plugs, ear muffs or landscaper radios to protect them from on-the-job noise. Landscaper radios are particularly nice because they not only limit outside noise but they also limit radio volume to a maximum 82 dBa. This type of limit protects crew members with a tendency to crank the volume on their music. Ear protection becomes more critical when using louder equipment such as chain saws. In these cases, purchase helmets that incorporate hearing protectors and face screens for full ear, face and head protection. In addition, make sure protective equipment carries ANSI-approved ear protectors that reduce noise levels by at least 22 dBA.
* Helmets. Also, look for the ANSI stamp on helmets. If the stamp is absent, then the helmet may not have been properly tested for rigidity and toughness. This is an important aspect to remember because many of the helmets available on the market are made with plastic materials that tend to lose their rigidity and toughness after sun exposure. Combination helmet and eye protection also is available. Most of this sort of combination wear is designed with chain-saw users in mind. Look for front-visor designs that eliminate the potential for dust and debris to fall between the mesh screen and hard cap and onto the face. You should be able to place the mesh screen and ear protection in either the up or down position for maximum safety, convenience and comfort. If you have any doubt whether the protective wear can fulfill its claims, ask dealers for an opportunity to personally test the gear.
* Gloves and mitts. When examining gloves and mitts, those offering the strongest grip and most durability are made of pigskin and nylon. Pigskin mitts dry to a better consistency and do not become slippery when wet. A few manufacturers offer mitts designed with a separate "trigger" finger on both hands, which increases dexterity and is an alternative to mitts with five full fingers or mitts with a sole finger design. Such mitts offer heightened gripping power and reduce the likelihood of jammed or twisted fingers. Consider purchasing these mitts for particularly long, demanding projects.
* First-aid kits. Keep a first-aid kit handy at all times. The Occupational Safety and Health Administration (OSHA) states that first-aid kits must be approved by your local health agency or physician.
Equipped with the right power equipment and protective apparel and knowledge, it is possible to vastly reduce the chances of on-the-job injury and long-term health problems. If making an ergonomics-related decision becomes difficult, contact local equipment dealers, manufacturers and industry trade associations for answers. Most are happy to help.
Mark Michaels is senior forestry manager for Husqvarna Forest & Garden Co. (Charlotte, NC)
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