Safe lifting techniques and injury prevention in the workplace

¶ … Lift Heavy Things in the Workplace

According to the Occupational Safety and Health Administration (OSHA), back injuries are the number one workplace safety problem. The Bureau of Labor and Statistics estimates more than one million workers each year suffer back injuries, accounting for some one-fifth of all workplace injuries and illnesses. According to the OSHA, one study concluded that fully one-third of such injuries could have been prevented by better workplace ergonomics. Adhering to proper lifting techniques would likely have reduced the injury rate further.

The Risk

The major risk from heavy lifting in the workplace is lower back pain. There are other risks, such as broken toes or other pulled muscles, but they are minor when compared to the millon-plus Americans who injure their back on the job each year.

The major cause of injury to the lower back is lumbar strain. The lower back (lumbar) region provides the structural support for the entire upper body. Due to its design, however, it is unable to support significant increases in weight. Lumbar strain is the result of tears to muscles, tendons or ligaments in the lumbar region.

The lumbar region consists of spinal discs, which are stacked together to provide a flexible support structure. These discs (the five lumbar vertebrae) are in turn supported by a series of ligaments, tendons and muscles (the paraspinal muscles). The lumbar region holds most of the weight of the body when we are standing. It is also a part of the body's stabilizing core. The lumbar spine and its muscles are needed for almost all movements.

In terms of lifting weight, injuries typically occur from improper technique. Because of the design of the lower back, and basic physical laws, the amount of weight carried will multiply several times in terms of the amount of force it applies to the lumbar region. For example, a 10-pound weight in your arms, if your arms are held out, puts 150 pounds of pressure on your lower back. This specific example illustrates why keeping the load close to the body is imperative, as will be outlined later.

As a result of improper technique, the muscles, ligaments and tendons are subject to what is typically a series of microtears that results in the generic term "lower back pain." A tear of the paraspinal muscles is called a "lower back strain"; a tear of the ligaments is called a "lumbar sprain." The result is inflammation of the soft tissue, which in turn causes pain and spasm.

Assessing the Situation

The first step in lifting a heavy object is to assess the situation. The first assessment should be of the object itself. It is important to get a sense of how much the object weighs before you attempt to lift it. The object should be inspected for signs of potential problems. These include sharp corners and slippery spots. If possible, the worker should try to find a handle or other good gripping spot. This handle or gripping spot should be evaluated for its ability to bear the load. The worker should not assume that because an object has a handle that the handle is able to bear the load. Many objects, but especially boxes, may be carrying more weight than they were originally designed for.

The next step is for the worker to evaluate his or herself. Many workplaces have requirements with regards to lifting ability. However, these are typically enforced only at hiring, if ever. It is important to remember as well that the worker's strength may have decreased since hiring, and that there may be other factors at play besides weight, such as load balance or the aforementioned potential problems. A worker's strength can also vary depending at what point in their shift they are attempting the lift. Workers need to have a sense at all times of their fitness capabilities. Inexperienced workers in particular need to consider their lifting capabilities since they may not yet have developed a sense of these.

If after these evaluations the worker determines that they do have the capacity to lift the object, they should then assess the environment. Many external factors can add risk to the situation. A check should be done of the floor, for both wet/slippery spots and for hazards. The path to the destination should be checked for debris and also for stairs, steps or other potential hazards. The end destination should be considered as well - the worker needs to be sure that they can safely place the object. This includes an evaluation of the height at the end destination - if this is higher than the height at which the weight will be carried this could present a risk. Any lifting which occurs below knee height or above shoulder height is more strenuous than that which occurs between these limits.

The Lift

Prior to the lift, the worker should be sure to be warmed up. No lifting should be attempted until the worker has done adequate stretching and warm-up exercises. Improper warm-up and stretching prior to exercise is one of the main causes of injury. Some of the exercises should be specific to building lower back strength.

There are eight components to a safe lift. The first is to stand close to the load, centered over it. The feet should be shoulder width apart. This illustrates one of the fundamental principles of lifting - stability. Muscle and joint injuries occur more easily when the body is unstable or uncentered. By centering the body and adopting a stable position, the muscles are allowed to work efficiently, reducing stress on them. Moreover, the fluidity of movement this allows reduces the risk of tear.

The second component is for the worker to tighten his/her abdominal muscles. The abdominal muscles, in particular the transverse abdominis, are one of the important sources of core stability. When they are tightened, they provide the lifter with additional stability, which aids in reducing stress on back muscles.

From there, the worker should bend his/her knees and squat down to the floor. The back should be kept straight while doing this. It is important to maintain stability at all times. The squat position forces the worker to lift using his/her legs. The fourth step is to get a solid grip on the load, with both hands. Maintaining this balanced approach to the load at all times is imperative - an unbalanced lifting technique will put added strain on one set of muscles at the expense of having the opposite set do less work. This is inefficient, and increases the risk of injury to the set that is doing the majority of the lifting. Even if the worker is stronger on one side than the other, they should maintain this balance. If the worker feels that one side is not strong enough to maintain the lift, they should seek help rather than attempt the lift his/herself.

The worker should keep the load close to his/her body, and stand. It is important to remember that only the legs should be used to lift the load. The arms can lend support but should not be relied upon as the legs are much stronger. If the arms were sufficient to lift, the load would not be considered heavy. At this point, the load should be re-evaluated. It should be judged again with respect to the ability of the worker to bear the load for the duration of the lift needed. It should also be judged in respect to its balance, as an unbalanced load can cause difficulties in transport. If the load is deemed too heavy or unbalanced, it should be returned to the ground. If unbalanced, the hands should be repositioned so that the load is more balanced and the lift re-attempted. It is risky to attempt to reposition the load while it is being held.

The back kept straight, and should not be used to help lift. When the back is used to lift, or assist the legs in the lift, this is a major source of workplace injury so it cannot be stressed enough that only the legs should be used. The back muscles are only designed with support of the body in mind, not to bear weight. A horizontal back means that hundreds of extra pounds of pressure are being placed on the lumbar region. The back should always be kept vertical. The legs are designed to bear heavy weights. The back should thus remain straight. The lift itself should be made with slow, smooth movements as jerky movements put added strain on the back.

The worker should never twist his/her body when moving the load. It is crucial that the worker maintain core stability in their lift, and twisting reduces this stability. The basic effect of twisting is that the role of the abdominal muscles in providing stability is reduced at the expense of the lower back muscles. The lower back muscles are able to bear less weight than the abdominal muscles. Thus, twisting increases the strain on the lower back and the risk of injury. In order to move the load, the worker should use their feet exclusively in changing direction, and walk in a steady, even stride towards the destination.

While moving, the load should be kept as close to the body as possible. This increases the stability of the load. If the load is held out, this increases the burden of the work to the arms and lower back. This results in a dramatic increase in stress to the lumbar region. The legs and abdominal muscles bear less of the workload. It should be remembered at all times that the legs are the strong muscle group and the abdominal muscles are the best source of core stability. To reduce their role in the lift is to increase the risk of injury to other muscle groups.

When the load has arrived at the destination, the process for set-down should be the reverse of the process for pick-up. The load should never be dropped. Rather, it should be set down, the worker keeping the load as close to possible to his/her body and bending his/her knees to bring the load to the floor.