Repetitive Strain Injuries – Prevention and Management
In the previous article, Repetitive Strain Injuries – Are you a victim of it?, we highlighted that repetitive strain injuries (RSIs) are mostly occupation related, but such oversue injuries can be caused by activities outside of work, such as sports and hobbies, including badminton, tennis, golf or playing a musical instrument.
Furthermore, older workers are more prone to RSIs because the body’s ability to repair the effects of wear and tear decreases with age.
RSIs are mostly caused by job demands and workplace conditions. If the conditions and demands of a job causes RSIs, they can be corrected by using ‘Ergonomics’, the science of matching jobs, systems, product and environments to the physical and mental abilities and the limitations of workers, instead of making the worker fit the job. Prevention of RSIs is possible if either ergonomical changes can be made to accomodate the worker, by changing the physical set-up of the workstation or he position or way one does his tasks, or both.
The following are ergonomically friendly suggestions to avoid RSIs.
- Avoid Repetitive WorkMuscles work by contracting and relaxing, stretching your tendons in the process. Repeated stretching and pulling can cause the tendon to swell and get sore. If the muscles and tendons do not get enough time for rest and recovery, the risk of injury is increased. This is because as muscles get tired from doing the same motion repeatedly, more effort is exerted to do the job.
Rest the muscles doing most of the work to prevent tiredness. Take frequent “micro” breaks, in which you use different muscles to do the task or pause for a few seconds. This relieves your muscles more effectively than uninterrupted periods of work with only one or two long rest breaks.
- Avoid Awkward and Static PosturesA “neutral” body position is the most comfortable working posture, in which the shoulders are downswards and relaxed, with the arms close by your sides, elbows bent with your wrists and hands straight. Deviating from the neutral posture will increase the stress on joints, muscles, tendons, nerves, and blood vessels. For instance, if you work bent over and leaning forward, with your arms above shoulder level in a “fixed” or “static” posture, you are likely to stress the lower back and shoulders. Such static activities are very tiring and stressful, and can potenially speed up the wear and tear of your back and shoulders.
Move around and change your posture often. Take “micro” breaks. If you have been bending or kneeling, switch to other tasks to rest your back and knees. Also, using the right tool for your tasks can reduce awkward postures. For example, using an Allen key instead of a screwdriver can reduce twisting and bending of your wrist at awkward angles.
In addition, minimize static postures that are “out of neutral” as these put further stresses on your body. For example:
- Work tables, chairs and countertops should be designed to eliminate frequent bending and extended bending and leaning
- Organize work tables so that materials are within easy reach
- Keep arms and elbows low and close to your body while working and reach without stretching and straining
- Keep reaches below shoulder level
- Avoid stacking materials above shoulder height
- Keep your elbows at the height of the work counter
- Support your forearms with armrests or other padded surfaces
- Have enough room in work area to use your arms while keeping your wrists straight
- Avoid Prolonged StandingStanding in one position for a long period of time can put stress on your spine, back muscles and legs.
The stress caused by prolonged standing can be reduced by:
- Using foot rests, to alternate the weight bearing foot by shifting your weight often
- Stand with knees slightly bent to prevent locking, and thus relieving stress in the knees
- Take “micro” breaks; general rule is a 5-minute break for every 45-60 minutes of standing. Take this opportunity to change positions or move around
- Reduce the Amount of Force You UseUsing a lot of effort & strength to do the job, even small movements like pounding fingers on keyboard will increase the stress your body takes. Forceful movements such as pushing, pulling, tugging, and sliding objects put strain on your lower back. They also stress the muscles, tendons, and joints of your shoulders, arms, upper back, and legs. The more force you use, the more you risk fatigue and injury.
- When moving a heavy object, use trolley, carts or equipment designed for pushing instead of pulling. Pulling stresses your shoulders and arms compared to pushing. This is because when you push, your body weight is being used to an advantage.
- Avoid pushing or pulling in an awkward posture as more force is required to move the object. Similarly, avoid pushing or pulling an object above shoulder height or below waist height. Modify your position to optimize your working position and strength.
- Look out for large amounts of friction between the surface and the object as this increases the force used. Put a medium between the two to reduce the friction i.e. wheels or sliding board.
- Be Careful How you LiftFaulty lifting techniques stress the back muscles, tendons, ligaments and spine. Even if the load is mildly heavy (less than 10kg), improper lifting can cause serious back injuries.
The key to proper lifting is to keep the back in its natural position. Squat lifts put less stress on your back, but only if you can fit the object between your knees. Otherwise, attempt to fit the object as close to your body as you can. The best solution is to reduce the size and weight of the load and make repeated trips. Here are some tips for a safer lifting procedure:
- Stand close to load with feet apart
- Tighten stomach muscles and tuck in bottom
- Arch your lower back inward by pulling shoulders back and sticking out your chest, keeping spine in neutral position
- Keeping spine upright, bend knees or squat down
- Face load directly. Do not twist your shoulders to reach the load. Bring object close to the body. The closer the load to the body, the less pressure it puts on your back
- Use stronger thigh muscles rather than smaller muscles of the back for the lift
- Never pick up a load unless both feet are firmly on the ground, and the load is no higher than your shoulders. Minimize long reaches and avoid fast, jerky movements
- Design Computer Workstations to Fit YouWorkstations must consider a worker’s ability to comfortably see and handle the work. Chairs with adjustable features and proper back support are essential to prevent injury and improve overall comfort and work performance. For example, the differences in chair height can affect the whole body.
If the chair is too high, it can:
- Press thighs against the table
- Press seat against back of thigh
- Reduce blood flow to the feet
- Make wrists bend up
- Force the head to lean forward and look down
If the chair is too low, it can:
- Raise knees higher than hips and encourage slouching
- Raise shoulders and arms causing stress and fatigue especially if the table is at chest level.
A good chair should have:
- Adjustable seat heights and depth
- Backrest that is adjustable for the height (up/down) and angle (forward/backward) to help support the lower backFurther suggestions can be found here.