There are no specific tests for confirmation of repetitive strain injury (RSI). Clinical features of pain and stiffness on particular movements and the progressive nature of the condition is often diagnostic of RSI.
Diagnosis is more of a challenge because pain in the muscles and joints may be caused by other diseases and injuries as well. Notable among this is accidental injury that manifests as sudden onset pain at the affected area rather than a diffuse and a longer lasting painful condition.
Process of diagnosing RSI
Steps towards diagnosis of RSI include taking a detailed history of the patient, examining the affected area and so forth. (1-4)
Detailed history of the patient
The patient provides a detailed history of:
- the onset of pain
- duration (this is an assumption since the symptoms are gradual in onset and patient often cannot pin point the exact time of onset)
- nature of pain
- swelling or inflammation
- nature of work
- history of repetitive activity
- forceful activity
- awkward or static posture or vibration exposure at work or at leisure related activities
Within the history patient provides clues as to what activity aggravates and what relieves pain. They may disclose the position and duration of rest to the affected muscle that provides relief from the pain and symptoms.
Examination of the affected area
On examination of the affected area, muscle or joint swelling, redness and tenderness is often noted. There may be weakness in the affected muscles.
For example, if the hands are affected the grip may be weakened. On movement there may be limited range of motion of the affected joint and sounds like popping or clicking.
Imaging studies like X ray, MRI and CT scans are not undertaken unless surgery is contemplated or there is a suspicion of an old fracture.
On X ray stress fractures, thinning and drying up (atrophy) of the cartilage and bone avulsions (breakages) as well as calcium deposits on tendons are noted.
MRI scans help detect damage to muscles, tendons and ligaments as well as soft tissues. They also help detect pinching or compression of the nerves in certain types of repetitive stress injuries.
Electromyography (EMG) and nerve conduction studies are often prescribed to check on nerve functions in these cases.
Bone scans are sometimes required to reveal stress fractures.
Alternative diagnoses with the same symptoms
Conditions that may be confused with RSI include several musculoskeletal disorders. For example, causes of neck pain may also present with features like RSI. These include:
- Acromioclavicular degeneration
- Suprascapular nerve compression
- Supraspinatus tendonitis
In the arms and legs the following conditions may mimic RSI symptoms:
- elbow degeneration
- anterior cruciate laxity
- pronator teres syndrome
- tibialis anterior tendinopathy
- tibialis posterior tendinopathy
- achilles tendon injuries and tendonitis
- ankle degeneration
- shin splints
- tarsal tunnel syndrome etc.
Laboratory studies include markers of other disorders like rheumatoid arthritis etc. to rule out conditions that mimic RSI.
RSI medical conditions
Several medical conditions may be seen as RSI. These include:
Bursitis - This is an inflammation and swelling of the fluid filled sac around knee, elbow or shoulder joints. This can occur at the knee, elbow, and shoulder and is called “beat knee”, “beat elbow” or “beat shoulder”.
Carpal tunnel syndrome - This is caused due to inflammation at the wrist leading to pinching or twisting of the median nerve passing through the wrist
Dupuytren's contracture - This is caused by thickening of deep tissue within the palms of the hand and fingers.
Epicondylitis - This commonly affects the joint between the bone and a tendon at the elbow joint. It is called tennis elbow or golfer’s elbow.
Rotator cuff syndrome - This is when there is inflammation of muscles and tendons in the shoulder
Endonitis and tenosynovitis - This involves inflammation of a tendon or the lining over it.
Ganglion cyst - This is a sac of fluid that forms around a joint or tendon, fingers or wrist.