Repetitive strain injury (RSI) refers to musculoskeletal disorders caused by repetitive movements over time. Common RSIs include carpal tunnel syndrome and tendinitis. RSIs develop due to ergonomic and psychosocial stressors and cause pain, numbness, and functional limitations. Occupations involving repetitive computer use or manual labor pose the highest risk. Diagnosis is based on symptoms and physical exam. Treatment focuses on rest, stretching, splinting, and therapies to address underlying muscle imbalances and stresses.

1. REPETITIVE STRAIN INJURY
AKASH JAINTH
MPT

2. DEFINITION
• Repetitive strain injury (RSI) is an umbrella term for a group of
disorders usually caused by repetitive movements that affect
the muscles, tendons and nerves.
• Unlike other injuries, which usually occur at a single point in
time, RSIs develop over an extended period.
• The origin and development of RSIs, however, are multifactorial
and controversial.
• Ergonomic stressors such as repetitive and forceful motions
have been implicated, as have psychosocial factors.

3. • Symptoms, usually pain, numbness and tingling, can last for
months or years.
• The impact of RSIs includes work disability, functional and
activity limitations, and sleep disturbances.
• More recently, RSIs have been linked with depression,
although whether depression follows or precedes an RSI has
been debated.
• Many studies of RSI have been cross-sectional, directed at
specific jobs, and have focused on either men or women.
• Relatively few have been longitudinal, conducted on a
population basis or have analyzed the sexes separately.
• Furthermore, much of the research has concentrated on the
most severe cases of carpal tunnel syndrome.

4. • RSIs can be divided into two broad groups: tendon-related
disorders and peripheral nerve entrapment disorders.
• Tendon related disorders involve inflammation of the tendon
and sheath or injuries to them. Common disorders include
tendinitis, tenosynovitis, epicondylitis (golfer’s or tennis elbow)
and rotator cuff tendinitis.
• Peripheral nerve entrapment disorders involve compression of a
nerve. The most common is carpal tunnel syndrome, which is
caused by compression to the median nerve.
• The second most common is cubital tunnel syndrome, caused
by compression to the ulnar nerve in the cubital at the elbow

5. MAGNITUDE OF THE PROBLEM
• In a research carried out by Dr. Saran a Repetitive Strain Injury
Specialist the following results were obtained :-
• 1 . Factory workers, Office workers, especially IT professionals
are highly predisposed to RSI.
2. Nurses, teachers, housewives, musicians and students are
also highly prone to RSI.
3. 75% of 5000 Indian Computer Users studied by our team
reported pain/numbness.
4. Over 30 young Indian IT/ITES Professionals have lost their
jobs because of advanced Repetitive Strain Injury (RSI).
5. 55% of Indian Computer Users got injured within a year of
starting their first job.

6. 6. Some types of RSI are responsible for up to 85% of all
instances of musculoskeletal pain in all age groups.
• In Canada, the leading cause of long-term disability is
musculoskeletal disorders (Spasoff el aI.,1987). In 1991, there
were 520,547 work-related injuries for which all Workers'
Compensation Boards and Commissions in Canada accepted
claims for time loss and permanent disability (Statistics Canada,
1992).
• This is a decrease of 12% from 1990 and results mainly from a
deterioration in labor market conditions. Canadian work injury
data revealed that the total number of lost time injuries caused
by work related strains and sprains in 1990 and 1991 were
251,106 and 228,161 respectively (Statistics Canada, 1992).

7. • Of the total number of injuries, the most frequent injuries
(44%) were sprains and strains. The back was the part most
frequently injured (29%), followed by the wrist, hands or
fingers (20%)
• A large UK study (9696 people) reported frequencies of lateral
epicondylitis (1·3% in men and 1·1% in women), de
Quervain’s disease (0·5% in men and 1·3% in women), and
tenosynovitis of the hand or wrist (1·1% in men and 2·2% in
women).31 Other studies have reported prevalence rates of
carpal tunnel syndrome of 7–14·5%.

8. • Repetitive strain injury is most common in specifi c professions
and industrial settings. In Australia, for example, high rates of
this disorder have been reported in men employed in industries
manufacturing textiles, footwear, food, and beverages. High
rates were also seen in women working in manufacturing of
basic metal, food and beverages, textiles, clothing, and
footwear.
• In the Netherlands, the professions with highest risk of repetitive
strain injury include tailors, dressmakers, construction workers,
secretaries, typists, people who use visual display units, and
those who load, unload, or pack goods.

9. PATHOPHYSIOLOGY
Several hypotheses for the pathophysiology of repetitive strain injury exist, but
none has been strongly supported by scientific evidence. Despite initial distal
presentation, this disorder seems to be a diff use neuromuscular illness.
Mechanical (elastic deformation of connective tissue due to increased pressure
within muscles) and physiological (electrochemical and metabolic imbalances)
reactions might cause damage to muscle tissue and lead to complaints of strain.
Continuous contraction of muscles from long-term static load with insuffi cient
breaks could result in reduced local blood circulation and muscle fatigue.

10. Some researchers have suggested that overuse of tendons by repetitive loading causes
repetitive strain injury.
Four pathological mechanisms have been suggested for tendonitis: decreased elasticity of
the tendon; friction between tendon and tendon sheath; tendon fatigue; and
mechanically-induced local temperature increase.
Most patients with true inflammatory tendonopathies have long-lasting symptoms of
degeneration of collagen fibre structure.
Other hypotheses suggest frequent co-contractions in muscles or changes in
proprioception as the source of injury

11. The function of peripheral nerves can be disrupted by
mechanical overload. In carpal tunnel syndrome, for
example, studies showed that specific forearm, wrist,
and finger postures, moderate hand loads, and
external pressure on the palm can increase carpal
tunnel pressure (at least temporarily) to levels at
which nerve health is threatened. Pressure in the
surrounding tissue, reduced elasticity, vibrations, and
direct compression of the nerves could reduce nerve
conduction

12. Types of RSI
• Experts often refer to two main types of RSI:
• Type1 RSI - usually caused by repetitive tasks, but not always;
some people who do not perform repetitive tasks may have
Type 1 RSI. The muscles and tendons swell.
• Examples of Type 1 RSI : Carpal tunnel syndrome, Tendinitis
(tendonitis), Tenosynovitis.
• Type 2 RSI - There is a feeling of pain but no obvious
inflamation or swelling in the area where symptoms are felt.
Often referred to as “when a person’s symptoms do not fit into
one of the (above listed) conditions,” also called non- specific
pain syndrome.

13. Who is at risk?
• The three primary risk factors are poor posture, poor technique,
and overuse.
• In addition to these, there are several other risk factors to be
aware of. While they may not cause RSI on their own, they can
increase your risk if you already possess one of the three
primary risk factors.
• Examples are: have a job that requires constant computer use,
especially heavy input, you don’t take frequent breaks, are
loose-jointed, you don’t exercise regularly, you work in a high-
pressure environment, you have arthritis, diabetes, or another
serious medical condition, you have an unhealthy, stressful, or
sedentary lifestyle and if you don’t sleep well.

14. Sign and symptoms
The most common RSI signs and symptoms include:
Tenderness in the affected muscle or joint
Pain in the affected muscle or joint
A throbbing (pulsating) sensation in the affected area
Pins and needles (tingling) in the affected area, especially the hand or arm
Loss of sensation in the hand
Loss of strength in the hand • Weakness, lack of endurance

15. DIAGNOSIS
• No gold-standard tests for repetitive strain injury exist. In most
cases, diagnosis is made on the basis of history and physical
examination, including assessment of range of motion of joints,
hypermobility, muscle tenderness, pain, strength, and
imbalance between right and left limbs.
• Some clinical tests are used for specific disorders. For example,
Phalen’s test, Tinel’s test, and measurement of nerve
conduction velocity are highly sensitive and specific for
diagnosis of carpal tunnel syndrome, which supports their
widespread use.

16. • Electrodiagnostic tests such as nerve conduction studies or
electromyographs might also be useful if clinical diagnosis is not
clear, although their diagnostic accuracy has not yet been
proven in high-quality studies with sufficient numbers of
patients.
• The American College of Rheumatology has published criteria
for imaging choices in chronic epicondylitis.
• They advise that MRI can provide important diagnostic
information for assessment of lateral epicondylitis, but that
ultrasonography is of little diagnostic value.
• However, a systematic review concluded that the assessment of
MRI findings in epicondylitis was questionable because the
diagnostic studies included were of low quality.
• Additionally, MRI is associated with high costs, and these
images are unlikely to affect treatment decisions or outcomes

17. Treatment
Rest the Affected Area. This is often the first recommendation. Moving the affected area is important,
but avoid stressing the joint. In conservation, this is often not practical without taking time-off from
work. Too much inactivity can cause atrophy of muscles and increase the severity of the disorder.
Stretching Routines are implemented to help reduce hypertonic muscles and increase their flexibility.
Splinting and Analgesics may help “mask” symptoms for a while, but unless the “real” cause of
dysfunction is eliminated, the symptoms come right back. The long-term success rate of Splints and Anti-
Infl ammatory

18. Contrast Baths (Hot/Cold) (contrast baths) are often recommended by a physical or
occupational therapist. Typical treatment protocol is approximately three (3) minutes of heat
followed by one (1) minute of cold alternating 3x, ending in cold. Heat alone is not
recommended
Ultrasound is okay if used in conjunction with a treatment program that includes soft-tissue
work, stretching of the flexor muscle group, and the strengthening of the extensor muscle
group. Ultrasound can help reduce inflammation in an acute case of tendonitis, carpal tunnel
syndrome, or other form of injury, but does no good when used alone.
Massage is good to have the flexor muscles massaged and stretched-out, but unless followed
immediately with strengthening exercises for the extensor muscles that extend the fingers,
elbow and wrist, and the abductor muscles of the fingers, it will have little effect on correcting
the muscle imbalance that causes carpal tunnel syndrome and repetitive strain injuries.

19. KEY POINTS
• Diagnosis of repetitive strain injury (RSI) relies on a careful history of work and
leisure activities and on physical examination checking for muscle strength,
sensation, and deep tendon reflexes. Special physical tests for certain
syndromes can also help.
• Magnetic resonance imaging is best for most RSIs but is not very accessible.
Ultrasound is
• more readily available. Electromyography is best for nerve entrapment
syndromes.
• Management strategies include modifying duties and ergonomic adjustments at
work and
• eccentric exercises, which allow the muscle tendon unit to lengthen against
resistance.
• Oral and topical nonsteroidal anti-inflammatory drugs and forearm bands reduce
symptoms, while steroid and tenoxicam injections are effective in certain cases.

20. Refernces
• 1. Macfarlane, Hunt, Silman. Role of mechanical and psychosocial factors in
the onset of forearm pain: BMJ. 2000
• 2. a b c Ring D, Kadzielski J, Malhotra L, Lee SG, Jupiter JB (February 2005).
“Psychological factors associated with idiopathic arm pain”. J Bone Joint
Surg Am 87 (2): 374–80. doi:10.2106/JBJS.D.01907. PMID 15687162.
http://www.ejbjs.org/cgi/pmidlookup?view=long&p mid=15687162.
• 3. “Two thirds of offi ce staff suffer from repetitive strain injury | Mail
Online”. Dailymail.co.uk. 2008-06-04. http://www.dailymail.co.uk/health/
article-1024097/Two-thirds-offi ce-staff-suffer-Repetitive-Strain-Injury.
html. Retrieved 2009-08-17.
• 4. Berkeley Lab. Integrated Safety Management: Ergonomics. Website.
Retrieved 9 July 2008. 5

21. • 5Ashworth N. Carpal tunnel syndrome. Clin Evid 2005; 14: 1351–65.
• 6 Assendelft W, Green S, Buchbinder R, Struijs P, Smidt N. Tennis
elbow. Clin Evid 2004; 11: 1633–44.
• 7 Binder A. Neck pain. Clin Evid 2005; 13: 1501–24.
• 8 Speed C. Shoulder pain. Clin Evid 2005; 14: 1543–60.
• 9 Bot SDM, van der Waal JM, Terwee CB, et al. Incidence and
prevalence of neck and upper extremity complaints in general
practice. Ann Rheum Dis 2005; 64: 118–23.
• 10 Health Council of the Netherlands: RSI. The Hague: Health Council
of the Netherlands, 2000: publication 2000/22. 11