December 2009, Vol. 21, No.12

Safety Corner

Ergonomic Considerations for the Wastewater Treatment Plant

Shawna Gill

If you have ever had your golf swing assessed or changed the height on your desk chair, you have had an ergonomic experience. Ergonomics is an assessment of work spaces to reduce physical injury produced by repetitive job requirements. Ergonomics considerations cross every work type, from golf pros to lab technicians. Review of body mechanics while performing a job, with options of change to reduce potential or known repetitive joint injuries, is the focus. Examples of this in the workplace include sitting or standing for long periods, lifting and moving materials, climbing a ladder, and driving a car.

Since safety is the primary reason for proposing ergonomic changes, it is important to identify tasks that currently cause problems or may lead to physical ailments. Alternatives or risk-averse solutions should be implemented to reduce the physical pains imposed by one’s job. Many simple and inexpensive ergonomic changes can provide maximum benefits. Reviewing each work space in the plant should reveal many opportunities for change that may lead to fewer sick days taken, as well as fewer complaints of aches, pains, and headaches. It is important to note that ergonomic considerations and solutions are not "one-size-fits-all" but instead are tailored to each individual.

 

Simple Changes

At first glance, sitting at a desk may appear to be the safest job in the plant, but a second look reveals more. There are numerous changes to a desk workspace that can reduce the risk of injury.

How one sits makes a huge difference. Sitting requires the torso muscles, including the stomach and back muscles, as well as the neck muscles, to be engaged or working for hours on end without reprieve — and that’s if you sit properly. But most people slouch in various forms, which may lead to headaches and lower-back, shoulder, and neck complaints. One small investment to provide a safe and comfortable "ride" is to use a seat that has a slight incline either forward or backward and offers height adjustment to allow one’s feet to rest comfortably on the floor.

Next, consider that the average human head weighs 13 lb (6 kg) — although it may feel far heavier as the hours pass when angled up or down constantly. To reduce strain on the neck, move computer monitors so that they are centered at the user’s eye level. This eliminates the need to look up or down at the monitor. This simple change can reduce neck and shoulder tension so often experienced by computer users. Even when a computer screen is not in play, work stations should be at eye level when at all possible. If this is not possible, taking the time to change positions, do another task, or stretch can aid in preventing stress or strain on the neck and upper-back muscles.

Wrist and hand alignment is another area primed for change for deskbound employees. The keyboard should be situated such that it allows the user’s wrists to remain in a neutral position with zero flexion up or down by the hand. Moving the keyboard itself can help to maintain a neutral position. If the desktop is too high, add a pull-out keyboard drawer or tray to the workstation. If the keyboard is too low, use wrist rests to even things out.

 

Within Reach

In addition, item placement on and in a desk can be arranged to maximize efficiency and reduce risks. Usually, office personnel bend from the sitting position to retrieve an item, but this is just as bad as bending over at the waist to pick up a box; both of these are wrong.

Commonly used items found in and on a desk should be placed within easy reach and not require stretching across or down. Repeated over time, both of these actions can lead to a sprain or strain of the shoulder, neck, or back muscles. Even bending at the waist to grab a file or pencil may result in a sprain or strain of the lower-back muscles.

It is not the size or weight of the item that causes injury; it is the improper lifting technique. If you need to bend over to get an item, use proper lifting technique. Get up from your seat, squat, bend both knees so you lower your torso while remaining upright and erect; do not bend at the waist. Once you are able to retrieve the item comfortably, do so. Then stand up using your legs. This lifting method should be used all the time when retrieving items from any space.

Correct lifting technique should be used even when you don’t think it is necessary because the item is not heavy. It’s worth repeating: The size and weight of the object being lifted is not always the cause of a lower-back strain. Bending from the standing position while overreaching and rotating toward the object on the floor is the common culprit that sends people seeking medical attention.

Furthermore, think about where supplies and spare parts are stored to minimize strain. How items are stored should be directly related to the frequency of use, object size and weight, and height of the person retrieving the items. Heavy objects should be stored on a shelf, no higher than waist level, or on the floor to eliminate the need for a step-stool or ladder. Reaching over one’s head to grab an object is unsafe — the item could fall, and overstretching may strain the back or neck.

 

Standing Tall

Additionally, standing for long periods can stress the body. Everyone is familiar with the aches that come from standing in a long amusement-park line or waiting to pay for items on Black Friday. Common complaints from prolonged standing include stiffness and pain in the feet, legs, thighs, lower and upper back, and neck – usually in a bottom-up order.

Proper shoes can make standing for such long stretches more comfortable. Proper shoes should have an adequate sole and arch supports and be breathable and insulated. They should be comfortable as soon as you put them on. A salesperson suggesting you just need to break them in is offering you many days of discomfort waiting for that to happen.

Standing on a rubber mat also can dissipate strain.

 

Walk This Way

Walking around the treatment plant also has its considerations. Whether the task is taking samples from an aeration basin or hosing down algae from a clarifier, good posture is a must. Do not lean over from the waist for long periods, as this focuses stress at the lower back.

Find a different vantage point or place to stand if your task requires you to lean over a railing or wall. Carrying an object should be done with both hands close to the body, and if the item cannot be carried in this manner, change hands periodically to equalize the stress on both sides of the body. Better yet, use a hand truck or cart.

Body mechanics aside, a clear walkway also is important to safety. Maintaining a safe, clean, and uncluttered walkway, office, laboratory, or other work area is critical to prevent trip or slip hazards. Job training should include thoughtful consideration of the path when carrying any items that may be difficult to maneuver around an obstacle.

If electrical or other cords passing a work area are necessary, these cords should be covered with rubber or other heavy matting that will allow a gradual path over the hazards.

Mats also are useful in areas prone to be muddy or wet to prevent slip hazards. Antislip tape, flooring, or coatings may be used in areas that tend to pose the consistent slip hazards. Slip-resistant shoes also support slip and fall prevention.

A review of the work setting probably will reveal many opportunities for simple and inexpensive ergonomic changes that can provide maximum benefits. Whether it’s as simple as rearranging a desk or always using proper lifting technique, the effects from these small changes will pay off in the short and long term.

Remember, ergonomic considerations and solutions are not one-size-fits-all; rather, they should be tailored for each individual. Take a look around your work area and see what you can do to make things safer.

 

Shawna Gill is a chiropractor, the chief executive officer of GillTrading.com Inc. (Beaverton, Ore.), and a vice chair of the WEF Safety, Security, and Occupational Health Committee.  

 

©2009 Water Environment Federation. All rights reserved.