Guest Author - Marji Hajic
Working on the computer or spending long periods of time at a desk can make you susceptible to developing a repetitive strain disorder (also commonly known as a repetitive stress disorder, a cumulative trauma disorder, or musculoskeletal disorder). Pain in the shoulders, neck, back, and arms can be common. Headaches and eye-strain are also frequently reported.
If you are feeling some pain, or concerned that you may be at risk, check out the following articles in the Repetitive Strain Injury series that take a closer look at why these injuries occur and specific ergonomic recommendations and injury prevention techniques for particularly painful areas.
The Fingers & Repetitive Strain Injuries The movement of bending the fingers is caused by the muscles in the forearm contracting and pulling on the tendon (the long, rope-like structure that connects muscle to bone) that attach to the fingers. These muscles actually start at the inside edge of the elbow.
The tendons that bend the fingers run through a pulley system within the finger itself. One of the most common repetitive hand injuries occurs within this pulley system due to friction from repetitive grip or sustained grip (such as when holding the mouse too tightly).
The Wrist & Repetitive Strain Injuries
The wrist joins the hand to the forearm. It is able to move forward and back, side-to-side, and in circular movements. This variety of motion allows the hand to reach objects and function in a wide range of motion. In addition, a strong and stable wrist is important during grip activities.
Many of the repetitive strain injuries associated with computer work occur at the wrist. In fact, according to the National Occupation Research Agenda for Musculoskeletal Disorders, the most frequently reported upper-extremity musculoskeletal disorders affect the hand and wrist region. Carpal Tunnel Syndrome and tendonitis are specific problems that may occur at the wrist.
The Elbow & Repetitive Strain Injuries
The majority of the muscles that bend the wrist and the fingers attach to the inner portion of the elbow. The majority of the muscles that straighten the wrist and the fingers attach to the outer portion of the elbow. Mouse use, reaching for the keyboard, or spending large portions of the day in a palm-down position can cause tendinitis or nerve compression at the elbow. Several specific injuries that can occur at or near the elbow include epicondylitis (golfer’s or tennis elbow) or nerve compression syndromes (radial or cubital tunnel syndrome).
The Shoulder & Repetitive Strain Injuries
The shoulder is a unique joint in the body. It has a great deal of mobility in order to allow us to reach and perform activities away from our body. The cost of this mobility is a lack of stability. Most of the stabilizing forces at the shoulder are muscular and ligamentous rather than bony. These soft tissues that provide the shoulder motion and stability can be at risk for repetitive strain injuries.
Poor posture can be a primary factor in developing shoulder pain. Other activities that tend to cause problems are prolonged or repetitive overhead reaching (such as when lifting binders or books down from shelves above the computer) or holding the arms elevated while typing or using the mouse. Ergonomic positioning can be very important in relieving shoulder pain. One study showed that a chair height that is 3 inches too low can cause excessive shoulder movements and reduce productivity by as much as 50%. Bursitis, tendonitis, muscle tension and “knots” and rotator cuff injuries are all common shoulder injuries associated with poor ergonomics.
The Neck & Repetitive Strain Injuries
Most often, neck pain and tightness is postural in nature. With repetitive desk or computer work, the head can gradually assume a position forward of its proper alignment over the shoulders. The more that the head creeps forward, the harder gravity pushes the head down, and the more rounded the shoulders become. This causes muscular strain, promotes muscular tightness and weakness, pinches the nerves and arteries, and compresses the cervical discs. Neck pain, shoulder pain, and headaches are often the result. In more serious cases, arm fatigue and weakness, impaired circulation, and numbness and tingling can occur.
Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing at the Hand Therapy & Occupational Fitness Center in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources.