Back safety usually gets glossed over with many "remember to bend your knees and not your back" remarks and posters as the safety class nods. But as an increasing number of employees begin to suffer from back pain and strain, it is not uncommon to hear them correct the cavalier attitudes of their fellow workers: "Listen up, it does make a difference how you lift." They now know from first-hand experience the damage one can do to a back through years of poor posture, improper body mechanics and lack of exercise.
Before one learns a list of back dos and don'ts, it is helpful to understand how the back works. This enables you to apply the why to all activities, whether it be lifting groceries, pushing a wheelbarrow or shoveling snow.
How the Back Works
The back is made up of a stack of blocks called vertebrae. The alignment of these vertebrae are critical in maintaining a healthy back. Craning the neck forward over a desk or table to read or to assemble small parts pulls these blocks out of alignment. Slouched sitting or bending over a pallet incorrectly initiates a constant strain on the lower vertebrae. In addition to alignment, the back's three natural curves keep the body balanced and allow you to move freely. These three curves are correctly aligned when your ears, shoulders and hips are in a straight line. As the low back (lumbar) curve carries most of the weight of the spine, it is imperative to maintain its alignment while performing the day's numerous activities.
The back is also made up of spongy cushions (discs) which are positioned between the vertebrae. These discs act like a car's shock absorbers. Bad shocks lead to an uncomfortable, bouncy ride. This is true for the back, as well. The discs become easily pinched by vertebrae when one's alignment is compromised by poor posture and improper body mechanics.
Lastly, abdominal, back and leg muscles support the body's curves and maintain alignment. They are the guide wires of the tower. If these muscles are weak or too tight, they will place added strain on the low back.
Keeping these factors in mind -- alignment, curves, healthy discs and strong, flexible muscles -- we are ready to attack any activity your employees perform. Well, maybe not all, but let's look at a few.
From when they get up until they go to bed, employees' backs are working. They have control over how hard they make their back work by the choices they make. Think about how much effort we place on preventing cavities or a heart attack. What do these have in common with the back? All three progress slowly; many times without flashing lights or warnings. Tooth decay gradually sets in, arteries become clogged over the years, and the back sustains constant unnecessary strain through bad habits. What can employees do to take action?
A common activity we all do is lifting. Whether it be crates, boxes of paper, sacks of onions, bags of kitty litter, your child, a suitcase or groceries, we all do some lifting. Most everyone has been taught to bend their knees while lifting. This is a good start, but it cannot be taught as the only important factor. Let's look at other critical components of a lift while taking into account how the back works.
B = Bow back in
A = Align vertebrae
C = Chin up
K = Keep feet on diagonal
These four components, known as B-A-C-K, assist people in maintaining their curves, keeping proper alignment, using their strong leg muscles and ultimately producing a safer lift.
As people plan for a vacation, so should they plan for a lift. They should be aware of how heavy it is. Do they need to get assistance or use mechanical help? Can the load be divided up? Where are they going with the load? Are they going to be tripping over wood scraps, other boxes, children's toys, etc.? Where will they put it -- on a pallet, shelf or counter? Is this space already cleared off so they will not have to juggle things with a load in their hands? Also, they should ensure that the load is carried to the correct place the first time so they will reduce the need to move the object twice. Using the brain before the back is the first step in a successful lift.
Once an employee has secured the best possible posture using B-A-C-K, he should keep the object centered and as close to the belt level as possible. One-sided lifts place an asymmetrical strain on back muscles and move the spine out of alignment. If the lifts are from a low position, workers should drop down on one knee. This way, they can get close to the object and place the load on their other knee (thigh) prior to standing. A stable ladder or step stool should be used to reach items above shoulder height. It is important to keep shoulders, hips and feet facing the object to avoid twisting. When possible, tip the item to test the weight. If possible, lower the item to a co-worker or lower shelf.
Reassess the storage of objects. Are heavy, frequently used objects stored above waist level? If this is the case, a little rearranging is in order to prevent back injuries and improve efficiency.
When performing repeated lifting (i.e., from a cart to a pallet), it is common to incorrectly perform this by adding a twist to the back. Twisting drastically increases the strain on muscles, misaligns vertebrae and weakens discs. Moving the feet, instead of the waist, to turn and face the load is important. Many back injuries that occur can be attributed to a lift with a twist.
When reaching into a bin, workers should straddle the corner with their legs and squat as far as possible. Next, slide the load as close as possible. They should brace their knees against the sides of the container for support and raise up, using their legs. If this position is not possible and the load is light, they can perform a bridge lift. To do this, workers grip the edge of the bin with one hand and raise one leg backward as they bend forward into the bin. They should press down on the bin with their hand as they raise themselves to a standing position.
Pushing and pulling is another common back activity. Given a choice, employees should choose to push as it is easier on the back. They should keep the same things in mind as with lifting, using B-A-C-K. In addition, they should use both arms to avoid twisting. If they must pull, they should stay close to the load and use an adequate height handle so they are not bent over.
Shoveling can be a lot of work on a back, but it doesn't have to be if done properly. First, workers should ensure that their grip and footing is solid. Teach them to tighten the abdominals to assist with the lift. They should keep the shovel close to their body and keep their bottom hand as low as possible to the shovel surface. This allows use of the arms and shoulders at a better mechanical advantage. Spinal alignment and diagonal foot placement is key. Lastly, employees should avoid twisting with a load. It may feel like more work on their feet to step and turn, but it is a tremendous load off the back.
Again, teach them to use their head before they use their back. What has to be dug? Where do they need to put it? Have them plan the best possible attack to avoid reaching, twisting and throwing the load clear across an area.
Standing, sitting and sleeping, surprisingly enough, also can take a toll on a back. In addition to working hard all day at protecting their backs, employees should take care of their backs while sleeping. They should replace sagging old mattresses and continue to think alignment and curves. Lying on the stomach will increase the lumbar curve. If this is a necessity, they can place a pillow under the hips to reduce the curve. When sleeping on their side, employees should align their head with the rest of their spine. It is common to tuck the head forward, placing strain on the neck. They should avoid rotating one knee higher than the other, which will place a strain on the low back. When sleeping on the back, employees should assess the pillow height. Does it push the head too far forward or fail to provide enough support to maintain alignment? If the low-back curve does not rest comfortably on the bed, employees should place a pillow under their knees to allow the curve to be supported by the bed.
Sitting keeps the spine in a flexed posture. It is important to stand up periodically to stretch the back from this position. It is more stable to sit with the feet firmly on the floor. If this is not possible, a footrest can be used. Sitting close to work is important to avoid bending over a desk or work table. Making the correct adjustments to your chair will make for a more supportive sitting position. Adjusting the height of the chair, backrest height, depth and seat tilt are important. If the backrest is nonadjustable, place a rolled towel or lumbar back pillow in the chair to help create a better support. Lastly, standing may feel hard on the feet and can be stressful to the back. Wearing supportive shoes is key for those who stand and walk full time. When possible, employees should prop one foot on a footrest or bar to reduce the weight placed on the back.
In addition to proper body mechanics, exercise plays a key role in maintaining a healthy back, even for the most strenuous jobs. Prior to any sport, activity or job, muscles need to be warmed up and stretched to prevent injury.
Warm-up: Your muscle groups need to be warmed up much like a car engine before taking off for the job. Starting the engine and running if for a few minutes makes the oil thinner, allowing for easier motion of mechanical parts. Likewise, warming up your muscles helps get blood circulating throughout the body and carries oxygen to the muscles to loosen them up.
Some examples of warm-up activities include a brisk walk around the work site, standing knee lifts, arm circles and jumping jacks
Stretching: Once employees are warmed up, their muscles need to be stretched to avoid tightening as they begin to work. Stretching lengthens the muscles, prepares them for activity and prevents injury from sudden jerking of tight muscles.
Strengthening: Strong muscles are essential for a healthy back. Abdominal muscles support the back and assist in good posture. Strong quadriceps (thigh muscles) allow for proper use of the legs during lifting, preventing overuse by the back muscles. Strengthening back muscles allows a back to perform efficiently and reduces the risk of injury when an employee needs to perform strenuous work.
The back is a complex structure of the body. It needs a little respect and care to last through a lifetime of wear and tear. Much like people take good care of their car or child, providing preventative maintenance or medical checkups, the back deserves similar concern. Because they have many years ahead of them to enjoy it, workers should think about their back as they perform their daily activities and ask, "What can I do to protect my back ?" Encourage them to make a quick checklist for their activities to determine if they are maintaining their curves, keeping their alignment and using strong muscles. Then they will be on their way to having a healthier back.
Marjorie Werrell, PT, CPEE, CIE, is a physical therapist and ergonomist. She provides job site analysis, training and ergonomic program development for Fortune 500 companies and government agencies. She participates on OSHA and ANSI teams. She is the president of ERGOWORKS Consulting in Gaithersburg, Md., and can be reached at (301) 294-3097.