Table of Contents
Introduction:
In today's world, young individuals are experiencing a significant lifestyle change. Such changes are often caused by lifestyle changes or occupational hazards. Such disorders are known as work-related musculoskeletal disorders (WMSDs). However, in most cases, the hand and wrist are the most commonly affected body parts. Repetitive strain injuries are a causative factor for such complications.
What Causes Repetitive Strain Injuries?
Repetitive strain injuries are not clinical conditions or disorders. Rather, repetitive strain injuries denote many musculoskeletal disorders that affect our daily lives. Repetitive strain injuries (RSI) occur or worsen due to repetitive or prolonged submaximal exertion on the body's soft tissue structures, such as muscles, tendons, ligaments, and nerves. According to researchers, 60 percent of occupational injuries are caused by repetitive strain.
The risk factors for repetitive strain injuries are,
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Prolong sitting or maintain the same posture.
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Continuation of the same movement for prolonged duration.
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Inadequate rest in between works.
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Doing repetitive and forceful work.
Exceeding the tissue's physical capacity can lead to muscle or ligament injury. This phenomenon leads to creep, where collagenous structures lengthen in response to extended submaximal loading. The recovery time from these changes may be several hours, making the tissue susceptible to damage from normally harmless forces. Prolonged submaximal loading, even as low as 5 percent, can lead to increased intramuscular pressure and ischemia.
As a result, changes such as expansion of the extracellular matrix collagen deposition around the muscle fibers and fiber necrosis of the muscles are observed. Additionally, such changes lead to permanent morphological changes in muscles. Inflammation plays an important role in the tissue injury associated with these repetitive injuries. The production of heat shock proteins (HSPs) is responsible for tissue damage, neural dysfunctions, and tissue ischemia. The production of various inflammatory mediators like interleukins and tumor necrosis factors causes tissue damage, fibrosis, and pain. Apart from inflammation, the pain and discomfort related to strain injuries also have a neural origin. Noxious stimuli cause the release of neurotransmitters like glutamate and substance P. Also, chronic mechanical injury causes nerve constriction and nerve compression.
Therefore, the repetitive strain disorders of the wrist and hand involve tendon-related complications and nerve entrapment disorders.
What Are the Tendon-Related Disorders Associated with Repetitive Strain Injuries?
Tendons are the fibrous tissue structures that connect the muscles and bones.
The tendon disorders caused by repetitive strain injury are,
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Tendonitis and Tenosynovitis: The inflammation of the fluid-filled synovium of the tendon. On the other hand, only the inflammation of the tendon is known as tendonitis. One of the most common tendonitis is De Quervain tenosynovitis. Repetitive wrist movement This is caused by myxoid degeneration (a degenerative change) and fibrous changes in the tendon. These factors cause thickening of the tendon and entrapment in the abductor pollicis longus and extensor pollicis brevis tendons. Patients exhibit radial-sided wrist discomfort that is usually aggravated by thumb and wrist movement. This issue could also result in pain or challenges when opening a jar lid. Rotator cuff tendonitis is another common form of tendon injury in the rector cuff tendon. Mechanical compression of the tendon causes tears, which cause degeneration, calcification, and collagen deposition. Patients often complain of difficulty in hand and elbow movements, mostly seen in overhead activities.
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Epicondylitis: This condition is also known as tennis elbow. The name is derived from a high prevalence of inflammation of the bending tendon of the wrist among tennis players. Tennis elbow commonly occurs due to overuse of the extensor tendon at the origin of the extensor carpi radialis brevis, particularly from the repetitive stress caused by tasks and activities that require frequent gripping and/or wrist extension. Pain and tenderness in the bony knob located on the outer side of the elbow are the primary indicators of tennis elbow. This knob is the point where the affected tendons attach to the bone. Discomfort may extend to the upper or lower arm, and a tennis elbow can affect both arms simultaneously.
What Are the Nerve Entrapment Disorders Associated with Repetitive Strain Injuries?
Compression of the peripheral nerve causes these types of complications.
These are,
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Carpal Tunnel Syndrome: This is one of the most common neurological conditions. It is caused by compression of the median nerve within the carpal tunnel (the passage between the bones of the palms of the hands), which causes pain and numbness in the fingers. Occupations like prolonged computer use, writing, or vibrating instrument use may cause such complications.
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Cubital Tunnel Syndrome: This is the second most common peripheral nerve complication associated with repetitive strain injuries. This can occur due to frequent bending of the elbows (such as when pulling, reaching, or lifting), excessive pressure on the elbow, or injury to the area. Additionally, arthritis, bone spurs, and previous fractures or dislocations of the elbow can also lead to the development of cubital tunnel syndrome. The most frequent signs of cubital tunnel syndrome include numbness and tingling in the hand or ring and little finger, numbness and tingling during nighttime, and pain in the hand.
How to Treat Repetitive Strain Injuries of Hand and Wrist?
Repetitive strain injury treatment includes both conventional and surgical approaches. These include;
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For mild tendon injuries, cold compression, elevation of the hand, and immobilization are required.
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Topical application of anti-inflammatory drugs is also useful for reducing symptoms, and local injections of steroid drugs can also be beneficial.
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For nerve compression, regular exercise and the use of ergonomics can be useful.
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The surgical interventions include decompression of nerve fibers and tendons.
Conclusion:
Repetitive strain injuries are a type of chronic injury that causes musculoskeletal complications. They are caused by excessive force, wrong posture, and repetitive injury. Repetitive injury of the hand and wrist causes tendon injuries and peripheral nerve injuries. Both conventional and surgical approaches can be used to treat such conditions.
