Pathology

     Due to the industrial revolution, followed by technological advances, the human hand is under much more strain and repetitive forces than it was originally designed for. Carpal Tunnnel Syndrome has been around for centuries, once a disease of "scribes", then "telegraphers' , and secretaries. And now it is an ailment to many people; particularly those working in manual positions in factories, and clerical positions requiring continuous keyboard entry .

     The median nerve may be compressed at the level of the wrist .Beneath the wrist, is the transverse carpal ligament and the carpal tunnel or mid-wrist and palm area, which can be compressed causing symptoms such as, decreased sensation or numbness of the first three fingers causing clumsiness, and weakness of the thumb or first three fingers and muscles affecting grip strength (particularly pinch and grasp). Carpal Tunnel Syndrome can be caused by many factors, or in some cases cause is not evident. A common cause is overuse of the muscles and tendons of the hands , causing inflammation and pressure in the "carpal tunnel, or wrist tunnel" which consists if many tendons, vessels, and other tissues in a tightly compacted area. When there is added compression or swelling, the main nerve to the thumb, index, and middle finger is also compressed.

     Increased intratunnel pressure is most common due to:

• the finger muscles (expanding) incursion into the carpal tunnel during grasp
• wrist positioning into extreme extension or flexion (bent position)
• externally applied force (e.g. splints, tool grips, leaning on wrists)
• swelling (e.g. during pregnancy, from acute injury or inflammation due to repetitive or use of powerful vibratory tools)
• other medical problems, causing inflammation or swelling, arthritis, fractures, etc.

     Non-operative Therapy

     Non-operative management is most likely to be successful with clients with intermittent or early symptoms. The purpose of treatment is to reduce the compressive forces on the median nerve in the carpal tunnel at the wrist area..

     Splinting with a wrist support aims to control the wrist position. Intratunnel pressures are lowest with the wrist in a mid-position, so the "wrist straight" is the suggested splint position. If symptoms are intermittent and not severe, a splint worn at night may provide adequate relief. Otherwise, it is generally recommended that the wrist be immobilized for a period of 3-4 weeks with gentle exercises to prevent stiffness.

     Its important to observe tools handles, and work postures, especially in the wrist, to encourage a neutral wrist position. Work habits, postures, repetitive forceful gripping, twisting or pulling motions also need to be assessed. Following are some other interventions used in the workplace for prevention:

• Try enlarged handles and grips to reduce pressure into the carpal tunnel. For example, padded steering wheel covers for driving, enlarged cutlery handles, and work tools are helpful. Prefer tool designs that maintain the wrist in a neutral position, padding and correct span for hand use.
• Proper set up at a keyboard or workstation is important for correct hand and wrist position, as well as limiting time for continous use at a computer with brief pauses included.
• It is each individual's responsibilitiy to examine work habits and postures as well , to prevent injury. Employers also are responsible for identifying potential hazards to employees.
• Review work tools, techniques or gloves to minimize external pressure and vibration over the carpal tunnel.
• Reduce any edema caused by inflammation, with rest, anti-inflammatory medications and cold modalities.

     Surgery and Post-Operative Therapy

     The aim of surgery is to reduce intratunnel pressure by releasing the transverse carpal ligament. This may be achieved by endoscopic or open release and is an ambulatory surgical procedure (1/2 day). Surgical release enlarges the carpal tunnel and relieves the pressure on the nerve. There is a small incision at the area of the ligament that is restricting the carpal tunnel, and a splint may or may not be provided for support immediately following surgery. One side effect after surgery, is that the altered biomechanics have been linked with a decrease in grip strength. But, in long-standing cases, nerve damage can be of worse consequences if ignored. Hand Therapy following surgery can help to prevent complications and restore function. The key to therapy is to influence post-operative scar formation, decrease pain, and increase strength with a shorter period of recovery and return to work or daily activity. Therapy may focus on:

• preserving the functional nerve gliding with specific exercises, avoiding the urge to use grippers or a "ball to squeeze"( not necessarily good to do)
• minimize scar hypersensitivity
• encourage quality of exercise rather than quantity
• avoid a return of increased intratunnel pressures by reviewing work habits/ergonomics
• minimize any reduction in grip strength or motion
• Work endurance may have been compromised for some time prior to the surgery, and it may take considerable time to restore good muscle fitness and balance for some jobs.
• Prevention is the key. A work-site evaluation can help if caused by repetitive forceful gripping, twisting, or poor hand/wrist posture at a keyboard or computer, with appropriate rest periods.
• If you suspect a problem, see an Orthopedic Hand surgeon or Hand Surgeon-Plastic surgeon that specializes in hand surgery, or see your medical doctor for appropriate exam/tests.

     Other web sites for carpal tunnel syndrome:

• Medical diagnosis & treatment:
  http://www.clark.net/pub/electra/cse0920.html
• Hand therapy (non-operative):
  http://www.eatonhand.com/thr/thr114.htm
  (post-operative):
  http://www.eatonhand.com/thr/thr116.htm
• Patient Information:
  http://www.sechrest.com/mmg/ctd/cts/cts.html

     Ms. Schwartz is a Registered Occupational Therapist at Elizabeth General Hospital in Elizabeth,N.J. She graduated from Towson University in 1983 with BS in Occupational Therapy. She also worked at Kessler Institute for Rehabilitation in New Jersey, a world renowned hospital for rehabilitation.