With the right work procedures and well-maintained equipment it is easy to prevent ergonomic injuries. Here is a typical situation.
For three years, a landscape maintenance crew member experienced intermittent tingling and numbness in his fingers accompanied by white blanching of his fingertips when exposed to cold weather. Recently the blanching occurred during warm months, and the worker noticed weakness in his hands and arms and a decrease in his ability to grip pruners, trimmers, shears, chain saws and other hand tools he used frequently during his 15-year career in the landscape industry. The worker saw a doctor, who diagnosed him with hand-arm vibration syndrome (HAVS). The condition is irreversible and will worsen with further use of vibrating tools.
Preventing HAVS and other ergonomics injuries associated with handheld tools is possible through proper work procedures, use of personal protective equipmentand tool maintenance. To avoid ergonomic injuries, operate power tools at the lowest speed necessary (for example, a chain saw operating at two-thirds throttle produces less vibration than one operating at full throttle), wear anti-vibration gloves, alternate use of vibrating tools with work tasks that don’t involve vibration, take frequent breaks, maintain tools so they, perform optimally (a clogged air filter, poorly tuned engine, dull saw chain or blades, etc. will increase vibration).
Proper maintenance is the frontline defense against many ergonomic injuries. It’s true that oddly placed shrubs, bushes or unconventionally shaped lawns lead to crews manhandling machinery, but even worse is using machines with dull blades, bad wheels or engines that are not well maintained. Fighting the lawn is a short-term problem, fighting the machine is an ongoing battle.
It is recommended to sharpen the blades of manual pruners, clippers and shears daily at the jobsite with a sharpening stone. Make certain you have the proper size file for sharpening your chain saw blade, and take it to the jobsite. Check and clean air filters weekly at a minimum, daily if necessary. Not having well-maintained equipment fatigues the body. Proper maintenance allows you to complete tasks faster and without as much force, arm motion or muscle wear and tear.
If a machine is equipped with a shoulder strap, adjust it to fit you and wear it. Also hold each tool by its handles and in the manner recommended by the manufacturer. If you are unsure of the correct ergonomic positioning, ask your supervisor to show you the owner’s manual.
High hand force – defined as gripping with the force needed to pick up an object weighing 10 pounds or more – is necessary for a multitude of landscaping tasks including pruning, trimming and holding power tools. Performing this action more than four hours per day (or more than three hours per day when combined with awkward wrist angles or repetition) is hazardous and will eventually cause ergonomic injuries. Alternate other tasks with this type of work or take rotating shifts with other workers.
All in all, it is easy to learn how to prevent ergonomic injuries if you take the aforementioned tips seriously and incorporate them into your daily work schedule.