by Dr. Timothy Jameson
Doctor of Chiropractic
Castro Valley, CA

Finger movement is facilitated by spaghetti like tendons that extend from the muscles in the forearms to various attachment points along the front and back of the fingers. Along their route to the fingers, these tendons must pass under a band of tough fibrous material called retinaculums. A retinaculum helps to guide the tendon to its insertion point, and acts as a retaining band and fulcrum that keeps the tendon in close proximity to the bones of the hand. The tendons become surrounded by fluid-filled protective sheaths as they pass under a retinaculum. This sheath prevents friction from occurring between the tendon and the retinaculum.

With overuse of the tendon from such activities as computer use, musical instrument playing, and hobbies such as crocheting and firing pistols or rifles, the sheath may become inflamed and the contents will thicken. This compresses the tendon as it passes through the sheath. Because of this constriction of the tendon, it begins to swell also. The tendon swelling tends to occur just before it passes through the sheath and retinaculum. In most cases, this involves the flexor tendons of the hand. This inflamed and enlarged flexor tendon will have difficulty passing through the swollen sheath and will have difficulty passing under the retinaculum.

The person suffering from this condition will notice that one or more fingers will get caught up as he/she tries to straighten them out. The finger will get stuck midway in a flexed position. The afflicted person will have to physically straighten the finger with the opposite hand. This procedure could painful enough to bring the person to tears. When straightened, the person may hear an audible snapping sound. This snapping is caused by the thickened tendon squeezing through the tunnel of swollen material.

Treatment of this condition should begin as soon as the person begins to notice difficulty moving the fingers. If treated early on, conservative measures will be effective to bring the inflammation down, and normalize tendon movement. Conservative measures should include primarily chiropractic spinal and extremity adjustments to normalize nerve flow to the hand tissues. You should also consider acupuncture, and myofascial therapy to release bound-up strain in the fascia, muscle, and tendons.

If the condition is allowed to progress whereby the finger cannot straighten, conservative measures should still be considered over a period of six weeks. If no relief if noticed in that time frame, then more invasive measures may be needed, such as corticosteroid injection, and possibly surgery to cut open the sheath to give the tendon more space to glide.

Several studies have reported an higher incidence of the development of trigger finger, carpal tunnel syndrome and tenosynovitis in diabetics. The use of corticosteroids in this population has not been very successful in remedying this disease, with only a 50% success rate. It is also noted that diabetics tend to have multiple digits involved. In these cases it is important to use conservative care initially, since most medically cared for individuals will usually require surgical intervention.

With any condition of an inflammatory nature, the key to prevention is education, proper biomechanics, and common sense. The biggest mistake people make is trying to work through the pain. Those computer users making thousands of keystrokes and under the pressure of deadlines are susceptible to these injuries. Also in danger is the musician who is under the gun to perfect a piece for an upcoming recital or gig. Many musicians will practice 6 hours per day to learn musical pieces. This puts a tremendous amount of strain not just on the tendons, but also on the musculature of the entire body.

An important aspect in prevention is to take frequent brakes while computing, playing an instrument, or enjoying your hobbies. I recommend at least a 10 minute break every 45 minutes for the health person. Taking a break does not mean heading to the coffee machine. Breaks should be a time for stretching of the hands, arms, and neck. If youve been sitting for the entire time, get up and move around, loosening up your legs and back. Give your body the attention it needs to keep you going throughout the day.

References:

Channas M, et.al., Dupuytren's Disease, Carpal Tunnel Syndrome, Trigger Finger, and Diabetes Mellitus, J Hand Surg [Am], 1995 Jan, 20:109-114

Griggs, et.al., Treatment of Trigger Finger Patients with Diabetes Mellitus, J Hand Surg, 1995, 20:787-789

Pascarelli and Quilter, Repetitive Strain Injury: A Computer User's Guide, Wiley, New York, 1994

Salter, Robert B., M.D., Textbook of Disorders and Injuries of the Musculoskeletal System, Williams & Wilkins, Baltimore, 1983

Robbins, et al, Pathological Basis of Disease, W. B. Saunders Company, Philadelphia, 1984