Background & Etiology
The carpal tunnel is a structure in the wrist, formed by the carpal bones and the transverse carpal ligament, which contains the median nerve, and flexor tendons. These structures travel through the carpal tunnel to stretch from the forearm through the wrist and into the hand.
The flexor tendons are strong, fibrous tissues that are responsible for transferring the forces generated by the muscle to the bone, thus producing movement at the joint. The nerves and tendons that travel through the carpal tunnel are what give feeling and movement to the hand and fingers.
The tendons in the carpal tunnel are enclosed in a sheath called the synovium. Swelling of the synovium puts pressure on the flexor tendons, thus restricting movement. In the confined space of the carpal tunnel, swelling of the synovium also puts pressure on the median nerve causing pain, tingling, and numbness in the hand.
Carpal tunnel syndrome is more common in women than in men, and in older individuals. Several factors can cause carpal tunnel syndrome including:
- Size of the carpal tunnel: some people have smaller carpal tunnels than others, and the smaller the carpal tunnel the more likely swelling of the tissues will impact the median nerve.
- Overuse or repetitive motion of the hand and wrist, for example people who type on a computer keyboard, perform repetitive work as on an assembly line, forceful gripping, or fine motor activities for their profession.
- Inflammatory conditions like rheumatoid and osteoarthritis can be a factor in carpal tunnel syndrome.
- Wrist pain or tenderness directly over the carpal tunnel that can radiate to the hand (most often the thumb-side) or forearm.
- Numbness, tingling and pain in the hand, particularly in the thumb, index and middle fingers
- Difficulty dressing and performing activities of daily living
- Pain that makes sleeping difficult, or wakes you up at night
- Weakness may occur as the inflammation gets worse
- Feeling of tightness or loss of motion due to discomfort
- Symptoms that occur infrequently, and become more consistent over time
If an individual suspects they have carpal tunnel syndrome, the initial treatment should consist of avoiding the positions and activities that produce the pain. In some patients, simply refraining from the activities that stress the hand and wrist can significantly improve the condition, if the symptoms are identified in an early stage.
A course of conservative treatment is usually recommended that would include rest and immobilization with a brace or splint that keeps the wrist in a steady position. Ice, hand therapy and non-steroidal medications to reduce inflammation can also be implemented. If symptoms persist, treatment by your physician may be necessary. This may include steroidal medication or injections, in conjunction with therapy. In severe cases surgical intervention may be needed to correct any mechanical causes of the tendon irritation.
Hand Therapists are occupational therapists or physical therapists who, through advanced study and experience, specialize in treating individuals with conditions affecting the hands and upper extremity. A hand specialist may also have advanced certification as a Certified Hand Therapist (CHT). A qualified hand therapist is educated and trained to administer interventions. As stated in The Guide to Physical Therapist Practice, interventions are the skilled and purposeful use of therapy methods and techniques to produce changes consistent with the diagnosis, prognosis and goal of the patient or client. Common interventions in the treatment of Carpal Tunnel Syndrome include:
- Manual Therapeutic Technique (MTT): hands on care including soft tissue massage, and joint mobilization by a hand therapist to regain mobility and range of motion of the wrist and hand.
- Splinting: Fabrication of custom-made splint or fitting of pre-fabricated splint by hand therapist to limit motion of wrist to decrease pressure and inflammation in carpal tunnel.
- Therapeutic Exercises (TE) including nerve stretching and tendon gliding exercises to regain range of motion of the hand and effected muscle.
- Neuromuscular Reeducation (NMR) to restore stability, retrain the upper extremity, improve movement technique and mechanics (for example, typing, hand fine motor activities, lifting activities), improve sensation in daily use of the involved upper extremity.
- Modalities that can include the use of ultrasound, electrical stimulation, ice, cold laser and others to decrease pain and inflammation at the hand and wrist.
- Home program that includes strengthening, stretching and stabilization exercises and instructions to help the person perform daily tasks and advance to the next functional level.
Procedures that your physician may recommend and perform in addition to physical therapy that include:
- REST and ICE
- The use of NSAIDS (Non Steroidal Anti-Inflammatory Drugs)
- Steroidal injections to reduce inflammation
- Pain medication to reduce the discomfort and allow the patient to perform the recommended exercises
- Splinting and immobilization to reduce stress on wrist
- Surgery to correct underlying pathology or the cause of the condition
Some patients recover full function following a course of conservative care that includes hand therapy, medication and/or injections. If surgery is required, it can take up to two months post surgery for full motor function of the hand to return.
It is important that once the pain and inflammation is reduced, and motion and strength are restored, the patient gradually returns to full activities. Instruction in daily activities or sport performance is helpful for reducing a reoccurrence of carpal tunnel syndrome.