Occupational overuse syndrome (OOS)

Occupational overuse syndrome (OOS) is a type of overuse injury and can be caused by:

• repetitive or sustained movement
• forceful contractions of your muscles
• awkward postures that you stay in for a long period of time (due to poor design of furniture or workstations).

Although OOS is usually related to occupations that involve awkward postures or repetitive movement, it can also be caused by activities away from work, such as from the repetitive movement of some house chores. Recreational activities that involve repetitive movements, such as playing musical instruments and training in high-intensity sports, can also contribute to OOS.

Psychosocial factors may contribute to OOS, including:

• stress
• excessive workload
• tight work deadlines
• poor and discouraging work environment.

OOS is a problem when your body’s capacity to take a load is exceeded by the demands of the activity. This means that although the load may appear light, if it is repetitive or stationary then its effect adds up. Addressing the problem requires both building up capacity (getting stronger or more skilled, and recovering better) and reducing demand (changing the way you do things or reducing the load).

The symptoms of OOS can affect any part of your body depending on which parts you use most. However, they are more common in your fingers, hands, wrists, elbows, shoulders, back and neck. Common symptoms include:

• muscle aches, pain or discomfort
• numbness or tingling
• muscle spasms or tightness
• muscle weakness
• swelling
• stiffness
• reduced range of movement in joints
• hot and cold feelings.

These symptoms will get worse and happen even when you are resting if they are left untreated in the early phase of the condition. Other symptoms that can accompany the condition include:

• loss of muscle strength and power
• burning sensations
• sleep disturbances.

Occupations or jobs that involve repetitive movement or sustained awkward postures could trigger and cause OOS, such as that done by:

• office workers or clerks
• typists
• cleaners
• machine operators
• labourers
• carpenters
• hairdressers
• musicians
• mail workers
• kitchen workers
• meat workers.

Your doctor can diagnose OOS based on the history of your symptoms, in particular, the factors that make it better or worse, and what your job is. Your doctor may also do blood tests and imaging tests such as x-rays, MRI or bone scanning in certain cases to rule out other conditions such as osteoarthritis or rheumatoid arthritis. 

Treatment aims to reduce pain and restore normal movement and function. Self-care measures and long-term strengthening are key to the treatment. Think of yourself as a ‘work athlete’. Having a well-designed exercise and recovery programme helps you maintain the work fitness that your job needs.

Treatment may include physiotherapy, occupational health review, medicine and/or exercise training. Surgery is only an option in rare cases when pain does not subside with continued self-care, strengthening exercises, physiotherapy and medicine.

The team of healthcare providers that may be involved in your care includes a GP, an occupational therapist, a physiotherapist, a hand therapist or a musculoskeletal specialist. A qualified exercise trainer may be able to support you with an exercise and recovery programme. Yoga, massage, mirimiri and other complementary health practices may also help.

Self-care

Self-care measures that could help speed up recovery and ease pain include:

• taking a rest from the problem activities
• taking up a ‘recovery’ activity eg, walking, aqua jogging or swimming
• changing and correcting postures
• using a splint or elastic support
• using hot and cold packs.

Physiotherapy

Strengthening muscles is extremely important for long-term care. A physiotherapist can show you progressive exercises to strengthen your muscles. They will explore how the pain influences your life and devise an individual plan with you. If your pain continues, they will also help you to work out how to move and do your required activities in different ways.

Medicine

Anti-inflammatory medications, such as ibuprofen, may be helpful for a few days. Some anti-inflammatories are available as a cream or gel that can be rubbed directly over the painful area. If you cannot take anti-inflammatory pain medication, other pain medication such as paracetamol may be helpful.

Corticosteroids may be injected around the area where the tendon attaches to the bone to help decrease swelling and pain, eg, if you have tennis elbow or where the nerve runs through a tight space, eg, if you have carpal tunnel syndrome.

Steroid injections may help ease pain in the short term but pain tends to come back in many people. You would need to rest the affected part of your body for a few days after such an injection, and slowly return to the progressive strengthening exercise and usual activity.

Surgery 

Surgery may be considered only if severe pain continues after 6–12 months of rest and treatment or if the condition is more likely to respond to surgery, eg, carpal tunnel syndrome. Your GP can give you more information about this option.

Most people with OOS recover after 3–6 months. However, recurrences are common as the factor causing the overuse injury, which is usually the activities related to your job, can be difficult to change. 

It can be difficult to avoid getting OOS and many people find it hard to stop doing the activities that cause it. The measures below may help you prevent the condition from developing or recurring.

In general

• Strengthen muscles around bigger joints to spread the load away from smaller joints.
• Increase activity levels gradually.
• Where possible, avoid prolonged and repetitive movement or straining.
• Learn ways to reduce stress, including through regular exercise.
• Avoid smoking.
• Seek help early to prevent symptoms from becoming severe.

If your condition is due to a repetitive activity such as sports

• Consider getting some coaching advice to help improve or modify your technique.
• Warm up well and gently stretch your muscles to help avoid injury.
• Use lightweight equipment and enlarge grip size to decrease the strain on your tendons.

If your symptoms are work-related

• Talk with your employer and colleagues about how you can avoid doing the activity that is causing pain or to do your job in a way that does not increase the pain.
• Seek help from an occupational nurse, occupational therapist, physiotherapist or other healthcare provider. They will work with you to find strategies or solutions that allow you to continue with your responsibilities at work without making the pain worse.
• Seek advice from your workplace health and safety representative or union delegate.
• Alternate tasks with different ones, if possible.
• Take frequent pauses to let your muscles and joints recover and re-set, even for 30 seconds.
• Where safe and practical, consider wearing gloves or changing the size or tackiness of equipment to reduce the effort needed to grip or hold.
• Review the height and ‘arms’ length’ at which you are working – can it be changed to make the work easier for you?
• If work involves lifting and carrying, can you use wheels?
• Give yourself permission to recover from each day’s work – with a walk, meditation or stretching.

Worksafe NZ(external link) is a New Zealand-based organisation that provides general information and resources regarding workplace health and safety. You can also makes claims in relation to work-related OOS through ACC NZ(external link), with a range of possible benefits and support.