Your Comfort Zone: The Ergonomics of Gardening
By Marcy Sanders, MA, MSOSH, OTR/L
Gardening represents a passion for some, and an opportunity to get outdoors and enjoy the sunshine for others. Because gardening is considered a leisure activity, we rarely think about the stressors it can bring to the body. Similar to work activities, gardening can create sore and aching muscles if we maintain awkward postures for a long time. Let's look at the ergonomic risks of gardening and solutions that can maximize your summer gardening enjoyment.
Gardening tasks and risk factors
The typical tasks associated with gardening include digging, raking, hoeing, seeding, watering, weeding, and harvesting (to reap the rewards of our efforts). Each involves biomechanical risk factors that may contribute to or aggravate an existing musculoskeletal condition. For example, digging involves bending the trunk for long periods, grasping tools with wrists deviated, and pushing feet forcefully against a shovel. Hoeing and seeding require kneeling with the trunk flexed for long periods. And weeding requires the use of a strong hand grasp to pull those tenacious weeds. As we've discussed in previous columns, these tasks may not present a problem if performed for short periods each day. If, however, we spend all day gardening on weekends and ignore our body signals that indicate fatigue, we might suffer aches and pains.
Minimizing ergonomic risk factors in gardening
As indicated in Table 1, most gardening tasks involve bending the trunk and low back, kneeling, and grasping. Therefore, try to minimize the time spent in these awkward positions and the hand forces used during gardening tasks. This can be accomplished by using good body mechanics and ergonomically designed tools that help keep joints in neutral positions.
The body mechanics principle of keeping the load close to the body pertains to both shoveling and overreaching for plants. When shoveling, bend your knees and hold the load close to your body, just as you would when shoveling snow. The farther the load is from your body center, the higher the compressive forces on your low back and spine. Ergonomic shovels have been designed with a bend in the shaft or with an additional handle on the shaft to support the load closer to your body center (see Figure 1).
Strain to the back or neck typically occurs when overreaching to maintain plants. You can minimize your reaches by keeping plants within a comfortable working area. A garden bed should be no wider than two feet if accessible from only one side, and no more than four feet wide if accessible on both sides. Other creative options to eliminate or reduce back strain while reaching for plants include the use of raised-bed gardens, container gardens, and vertical-growing plants (such as growing on trellises). A raised bed of 36 inches (using stacked cinder blocks, crates, or even old washtubs) will nearly eliminate low-back flexion for most adults.
Ergonomic tools for gardening
Numerous ergonomic gardening tools have been developed to enable gardeners to work more efficiently with less force. Ergonomic gardening tools should keep the wrist in neutral (straight) position, be lightweight, and require lower forces than traditional tools. Use of the wrist in a neutral position enables the strongest gripping force. Ergonomic weeders, trowels, and fork tools are now designed with a pistol grip to maintain the wrist in a neutral position (see Figure 1). Arm-support cuffs can be added to the tool to provide greater leverage and stability (see Figure 2).
The handle surface should be a comfortable, textured grip. Extended handles on tools can safely increase reaching potential without increasing strain on the back. Many tools are now available with extension handles (trowel, hoe, rake), measuring from 31 inches to 35 inches. Don't forget to use padded mats to protect your knees or even small ergonomic stools to alter your position.
Take a break (this is supposed to be fun)
Finally, regardless of the task, take frequent rest periods to minimize the build-up of muscle forces, stretch in opposite positions (such as standing to extend the back), and keep the body hydrated. The rewards of beautiful plants and fresh vegetables are worth time invested in this healthy leisure activity. A few tips can make gardening a lot more comfortable.
Martha J. Sanders is an assistant professor of occupational therapy at Quinnipiac University in Hamden, Conn. She has worked with dental practitioners for more than 15 years in rehabilitation and prevention of musculoskeletal disorders. Sanders is the editor of a textbook on ergonomics, "Ergonomics and the Management of Musculoskeletal Disorders." E-mail her at [email protected].
