Synonym: cumulative trauma disorder
Overuse phenomena are usually seen in the wrists and hands. Cumulative microtrauma causes tendinopathy and tenosynovitis (inflammation of the tendons and synovial sleeve). When tenosynovitis is the result of repetitive movements (eg, using a keyboard) the condition is called repetitive strain injury (RSI).
RSI can be classified into type 1 and type 2. Type 1 includes well-defined syndromes such as carpal tunnel syndrome, tendinopathy and tenosynovitis. Type 2 includes cases in which symptoms do not fit into a well-defined syndrome. Also, there are no objective or measurable signs such as inflammation, swelling or problems with nerve function. It is sometimes called nonspecific pain syndrome.
The mechanisms involved in the production of the 'inflammation' associated with cumulative trauma are not clearly understood but many factors have been implicated including mechanical fatigue involving ligaments, tendons and soft tissues. Damage to neural tissue from ischaemia has been mooted, as has damage to muscle tissue relating to adenosine triphosphate (ATP) depletion. Psychosocial factors also seem to play a part, particularly in RSI.Research suggests a role for co-ordinative variability (the variability of the interaction between segments or joints). There is a normal range of variability at either extreme of which overuse injury is possible.Another development is the identification of chemical agents called alarmins, thought to be involved in a variety of inflammatory processes, including repetitive strain tendinopathies.
- The exact incidence of overuse phenomena is unknown because the condition has not been clearly defined.
- An American study of high school runners found that 68% of female subjects and 59% of male subjects had a history of overuse injuries.
- One study found that the number of repeated trauma cases accounted for 4% of total workplace injuries and 65% of all occupational illnesses, with work-related upper extremity disorders accounting for most cases.
- Several occupations have a high incidence of overuse injury - this includes those who work as ultrasonographers, assembly line workers, tailors, surgeons, dentists, nurses and anyone involved with heavy computer work.
- There are associated sporting activities - these include those who are equestrian athletes, swimmers, golfers and martial artists.[8, 9]
- The presenting symptoms depend on the site of the inflammation and various syndromes have been reported. All have in common pain as the primordial feature.
- A careful history should be taken to identify any aggravating or relieving factors.
- The patient may have already identified an occupational or leisure-related activity that brings on the pain.
- Associated symptoms may include clicking, 'popping' or rubbing of a tendon, or overlying erythema.
- Examination findings will depend on the underlying condition and cause.
- Commonly, swelling, erythema and tenderness may be found over the affected tendon.
- Crepitus may be demonstrated on movement and the range of motion may be found to be limited on active and passive movement of the relevant joint.
Depending on the site of inflammation, the following may need to be considered:
Neck and shoulders
- Other causes of neck pain.
- Acromioclavicular degeneration (eg, acromioclavicular joint injury).
- Suprascapular nerve compression.
- Subacromial pain.
- Carpal tunnel syndrome.
- Elbow degeneration.
- Gamekeeper's thumb.
- Knee degeneration.
- Anterior cruciate laxity (eg, anterior cruciate ligament injury).
- Pronator teres syndrome.
- Shin splints.
- Tibialis anterior tendinopathy.
- Tibialis posterior tendinopathy.
- Achilles tendinopathy and rupture.
- Ankle degeneration.
- Tarsal tunnel syndrome.
The diagnosis is usually made clinically but investigations may be contributory in certain situations.
These are rarely helpful, although inflammatory markers and autoantibody screening may be helpful in excluding systemic joint conditions.
Imaging is not performed on most patients, unless surgery is being considered, in which case it is vital to support the diagnosis.
- Radiography may show bony avulsions, stress fractures, cartilage atrophy or calcification of a tendon.
- Bone scanning is sometimes required to reveal stress fractures.
- MRI may contribute in a variety of ways, demonstrating damage to muscles, tendons and ligaments, although it is more specific in acute than in chronic injury. It may demonstrate bone marrow oedema associated with stress fractures and may also assist in the diagnosis of nerve compression syndromes.
- Electromyography (EMG) and nerve conduction studies may be helpful in diagnosing peripheral nerve compression or injury.
- The role of the physiotherapist in these conditions is to institute a regime which rests the affected part whilst encouraging non-painful exercises which prevent restriction of movement.
- Other modalities used include transcutaneous nerve stimulation (TENS), ultrasound and interferential treatment.
- The patient should be encouraged to avoid any activity or movement which is a clear aggravating factor.
- A balance between reducing the extent of movement whilst maximising performance quality needs to be achieved in certain occupations, arts and sports (eg, shoulder movements in baseball).
- This can help to modify work and leisure activities in order to prevent the condition from recurring (see 'Prevention', below).
- Non-steroidal anti-inflammatory drugs (NSAIDs) are useful in reducing musculoskeletal inflammation.
- There is evidence to suggest that simple analgesics may work equally well.
- Other treatments that may be of benefit include muscle relaxants and tricyclic antidepressants.
- Corticosteroid injections, often used in combination with local anaesthetic, are beneficial in treating local tendinopathy or tenosynovitis.
- This may be indicated when conservative treatment fails, to decompress nerves or repair ligaments.
- Surgery should only be undertaken if a specific diagnosis has been established, not simply because pain has persisted despite medical treatment.
Controversies concerning RSI
- Diagnosing a patient with RSI has always been a controversial issue, not least because of the litigation issues surrounding action against an employer.
- Psychological factors would appear to play a part and stress at work is a known aggravating factor. One study focused on 'liminality' - a state in which often previously conscientious workers would become so self-absorbed with their condition that this inhibited their recovery.
- Many authorities recommend diagnosing RSI only in the presence of consistent subjective symptoms, demonstrable gross and microscopic pathological features and appropriate responses to therapy.
- This leaves a large section of patients who have a rather vague unclassified condition which would not fit these criteria.
- Complications are mainly iatrogenic, arising from adverse effects of drugs and infection or bleeding after surgery.
- However, there may be adverse effects on employment or leisure activities, especially sports activities.
Most injuries recover after three to six months. However, recurrences are common unless the original aggravating factor is removed.
- This involves minimising the overuse or repetitive microtrauma and reducing exposure to force, vibration and repetitive movement.
- Occupational therapists can be helpful. Often, simple modifications are sufficient. Occupational therapists are often called upon to advise employers about wider-scale changes to reduce the risk of workforce injury in the commercial sector.
- Compilation of data at a workplace/company level can be a useful source of information in the planning of preventive measures with respect to occupational overuse risk reduction.
Further reading and references
Gold JE, d'Errico A, Katz JN, et al; Specific and non-specific upper extremity musculoskeletal disorder syndromes in automobile manufacturing workers. Am J Ind Med. 2009 Feb52(2):124-32. doi: 10.1002/ajim.20653.
Barr AE, Barbe MF, Clark BD; Work-related musculoskeletal disorders of the hand and wrist: epidemiology, pathophysiology, and sensorimotor changes. J Orthop Sports Phys Ther. 2004 Oct34(10):610-27.
Hamill J, Palmer C, Van Emmerik RE; Coordinative variability and overuse injury. Sports Med Arthrosc Rehabil Ther Technol. 2012 Nov 274(1):45. doi: 10.1186/1758-2555-4-45.
Millar NL, Murrell GA, McInnes IB; Alarmins in tendinopathy: unravelling new mechanisms in a common disease. Rheumatology (Oxford). 2013 Jan 28.
Tenforde AS, Sayres LC, McCurdy ML, et al; Overuse injuries in high school runners: lifetime prevalence and prevention strategies. PM R. 2011 Feb3(2):125-31
Giang GM; Epidemiology of work-related upper extremity disorders: understanding prevalence and outcomes to impact provider performances using a practice management reporting tool. Clin Occup Environ Med. 20065(2):267-83, vi.
Ageing and work-related musculoskeletal disorders. A review of the recent literature; Health and Safety Executive, 2010
Pugh TJ, Bolin D; Overuse injuries in equestrian athletes. Curr Sports Med Rep. 2004 Dec3(6):297-303.
Junge A, Engebretsen L, Mountjoy ML, et al; Sports injuries during the Summer Olympic Games 2008. Am J Sports Med. 2009 Nov37(11):2165-72. doi: 10.1177/0363546509339357. Epub 2009 Sep 25.
Managing upper limb disorders in the workplace; Health and Safety Executive, 2013
Ivkovic A, Franic M, Bojanic I, et al; Overuse injuries in female athletes. Croat Med J. 2007 Dec48(6):767-78.
Lisle DA, Shepherd GJ, Cowderoy GA, et al; MR imaging of traumatic and overuse injuries of the wrist and hand in athletes. Magn Reson Imaging Clin N Am. 2009 Nov17(4):639-54, vi. doi: 10.1016/j.mric.2009.06.007.
Misra UK, Kalita J, Nair PP; Diagnostic approach to peripheral neuropathy. Ann Indian Acad Neurol. 2008 Apr11(2):89-97. doi: 10.4103/0972-2327.41875.
van Tulder M, Malmivaara A, Koes B; Repetitive strain injury. Lancet. 2007 May 26369(9575):1815-22.
Boocock MG, McNair PJ, Larmer PJ, et al; Interventions for the prevention and management of neck/upper extremity musculoskeletal conditions: a systematic review. Occup Environ Med. 2007 May64(5):291-303. Epub 2006 Sep 14.
Urbin MA, Fleisig GS, Abebe A, et al; Associations between timing in the baseball pitch and shoulder kinetics, elbow kinetics, and ball speed. Am J Sports Med. 2013 Feb41(2):336-42. doi: 10.1177/0363546512467952. Epub 2012 Nov 29.
Jacobs K, Kaldenberg J, Markowitz J, et al; An ergonomics training program for student notebook computer users: Preliminary outcomes of a six-year cohort study. Work. 2013 Jan 144(2):221-30. doi: 10.3233/WOR-121584.
Wilson JJ, Best TM; Common overuse tendon problems: A review and recommendations for treatment. Am Fam Physician. 2005 Sep 172(5):811-8.
Goldman RH, Stason WB, Park SK, et al; Low-dose amitriptyline for treatment of persistent arm pain due to repetitive use. Pain. 2010 Apr149(1):117-23. doi: 10.1016/j.pain.2010.01.016. Epub 2010 Feb 20.
Winspur I; Controversies surrounding "misuse," "overuse," and "repetition" in musicians. Hand Clin. 2003 May19(2):325-9, vii-viii.
Jaye C, Fitzgerald R; The embodied liminalities of occupational overuse syndrome: Medical anthropology quarterly. Med Anthropol Q. 2012 Jun26(2):201-20.
Karwowski W; International Encyclopedia of Ergonomics and Human Factors, Second Edition, 2010.
Bass E; Tendinopathy: why the difference between tendinitis and tendinosis matters. Int J Ther Massage Bodywork. 20125(1):14-7. Epub 2012 Mar 31.
The costs and benefits of active case management and rehablitation for musculoskeletal disorders; Health and Safety Executive, 2006
van der Beek AJ, Mathiassen SE, Burdorf A; Efficient assessment of exposure to manual lifting using company data. Appl Ergon. 2013 May44(3):360-5. doi: 10.1016/j.apergo.2012.09.006. Epub 2012 Oct 12.