Tools, machines and workplace equipment are often designed and built without consideration for the people who use them.
On some jobs you have to pull, push or reach up all day long and your arms and neck hurt by the end of the day. Or your hands and wrist ache. Or you have to be an acrobat to get the work done.
Poorly designed equipment may cause more than fatigue and discomfort. It may lead to physical injury, disability, work loss and surgery.
Usually these problems can be corrected with engineering changes and your job may become easier to do and your work quality improve at the same time.
This factsheet contains information on job design to prevent injuries, aches, strains and sprains.
Most of what is talked about here may seem like common sense and it is. But it is also based on sound scientific principles from the field of ergonomics, which is also known as "human factors engineering".
The basic principle involved is to make the job fit the person, not to make the person fit the job.
Hands and wrists are vulnerable to poor design of tools and equipment because they contain a delicate collection of nerves, tendons, ligaments, bones and blood vessels. Damage can occur from:
Work under these conditions can cause damage to hand or wrist. The problem is caused by doing the same damaging thing over a long period of time. These injuries are sometimes called repetitive or cumulative trauma.
Carpal Tunnel Syndrome is associated with a bent or twisting wrist, especially under force. The nerve which runs through the wrist (the Carpal Tunnel) is damaged by excessive repetitive pressure.
Symptoms include: numbness, tingling and burning sensations; pain; wasting of the muscles at the base of the thumb; dry shiny palm; and clumsiness. Symptoms may be felt in only one part of the hand and may be strongest at night.
The treatment is to remove the cause of the problem by reducing the number of repetitions done and redesigning the work.
Tendonitis is associated with repetitive motions. Tendons become sore or inflamed because of overuse. Different tendons may become damaged depending on what movements are overdone.
Symptoms include: pain, swelling and redness of the hand, wrist, or forearm. Often use of the hands and fingers becomes reduced.
Tendonitis can be treated through rest, perhaps in combination with heat and a splint, but only if the cause is eliminated.
White finger is associated with vibrating tools. The hands blood vessels become damaged and eventually spasm because of vibration. The skin and muscle tissues can't get oxygen and eventually die.
Symptoms include: loss of feeling and control in the hand and fingers; numbness of fingers and a tingling sensation; a blanching of the skin; loss of control of hand muscles; clumsiness; a reduced sense of heat, cold and pain.
There is no effective treatment for white finger. If the exposure is stopped and the worker is young and healthy the condition might improve.
Arms and shoulders can be affected by poor workplace design. Working with outstretched arms or elbows held high can cause excessive muscle fatigue and pain. Over a long period of time this can become disabling. Repetitive elbow and shoulder movements can cause damage to tendons. Joints can be damaged by an extreme range of motions if done repeatedly.
Jobs should be designed so that the arms do not need to be raised above shoulder height on a regular basis. Arms should be kept low and elbows should be kept close to the body.
Lifting objects from the floor can hurt. Lifting objects overhead is also hazardous. It is best to build platforms to store objects off the floor, above knee height, to elimnate the need for stooping and also to keep materials below shoulder height.
The further away from your body you hold something the harder it is on your back. Work stations should lessen the distance between a lifted object and your body.
Shelves, supports or roller conveyors on which objects can slide eliminate unnecessary lifting. Reaching down into a bin is poor workplace design. Bins should be of the floor and tilted to ease loading and unloading. Pushing and pulling can cause back injuries. Twisting, stretching or leaning with a heavy load can cause back problems.
Work stations should be designed to fit the workers. For example, the workbench should be on an angle, not the workers back.
To eliminate back strain lifting should be eliminated.Lifting from the floor can put a great strain on your back. Proper lifting methods are not a substitute for redesigning the workplace.
However, when it is unavoidable the following are rules for lifting:
Standing too long can put excessive stress on the spine and back muscles causing pain and even permanent damage to body tissues.
Solutions include: providing a foot rest and standing with one foot up. This lessens back stress. Change legs often. Provide mats and floor coverings. Provide a stool. Provide opportunities to change position, move around or alternate between sitting and standing.
Sitting is often better than standing but the chair should be designed correctly for the job and the person. Poor chairs can contribute to back problems, circulation problems, and breathing problems. The height of the chair should fit the height of the workbench and the job. The height of the work surface should fit the job and the individual worker.
Every year 600,000 American workers suffer ergonomic damage.This epidemic of injuries is preventable.
As this drawing shows work can be redesigned to fit the workers. It is damaging to work with your arms above your head, but auto bodies are not hurt by turning them on their sides.
OSHA says it's proposed ergonomic standard, currently blocked by Congress, will save billions in medical and associated costs. Work should be designed to fit workers.
Contact SEMCOSH for more information and to get involved with the campaign to establish ergonomic standards in the workplace.