Carpal tunnel syndrome is a condition that causes symptoms of pain, numbness and tingling in the median nerve distribution of the hand (at the ends of the thumb, index, middle and half of the ring finger). Pain may radiate from the wrist and hand into the forearm, shoulder and neck. Symptoms are frequently worse at night. Patients will also complain of dropping items and difficulty with fine manipulation tasks. Left untreated, weakness may develop in the hand as the motor portion of the nerve is affected. Visible atrophy (loss) of muscle will occur in the thumb region.
The carpal tunnel is located at the base of the hand/wrist. It is comprised of eight carpal bones that are shaped in an arch and a ligament (flexor retinaculum) that spans the arch creating a tunnel. Nine tendons (two to each finger and one to the thumb) and the median nerve travel through this small tunnel. On either side of the carpal tunnel are the muscles that operate the thumb and small fingers.
Inflammation and swelling of the flexor tendons and their sheaths within the carpal tunnel cause compression and loss of blood flow to the median nerve in the carpal canal leading to the symptoms described above. Heavy development of muscles in the hand may also contribute.
Risk factors for carpal tunnel syndrome include:
Overuse conditions including prolonged, forceful, repetitive and tight (small circumference) grip activities
Vibrating tool use
Work/use in cold environment
Congenitally small carpal tunnel
Degenerative changes in the carpal bones that decrease the size of the carpal tunnel
Prior wrist fracture or trauma
Diabetes, obesity, nicotine use, female, advancing age, thyroid disease, post menopausal, steroid use, inflammatory arthritis
Pregnancy due to increased fluid and blood volume
Very muscular hands (intrinsic muscles move into the carpal canal during grip activities)
Findings not consistent for occupational computer use resulting in increased incidence of CTS vs. the general population in some studies.
There are other conditions that may contribute to similar symptoms which are important to distinguish and treat accordingly. A detailed assessment by a qualified physical therapist will help to determine if these conditions exist. Your physical therapist or doctor may recommend Nerve Conduction Velocity (NCV) and EMG (muscle activity) testing to help determine location and level of nerve involvement.
These conditions include:
Cervical radiculopathy or nerve root impingement from neck. (EMG/NCV will also test for this.)
Thoracic outlet syndrome or nerve impingement in area of neck muscles, clavicle (collar bone) and upper rib cage. (Will not show on EMG/NCV.)
Adverse mechanical neural tension. Tethering of median nerve elsewhere along its course from the neck to the hand. (Will not show on EMG/NCV.)
Not unusual to have a “double crush” syndrome with more than one location of nerve involvement.
Surgery may not always be the first or only option for treating carpal tunnel syndrome. Non-surgical or conservative care frequently includes splinting of the wrist in a neutral position at night to maximize volume in the carpal canal as well as specific hand and finger exercises for flexibility and gliding of tendons and nerve. It is also important to address shoulder, upper back, and neck contributions with a strong emphasis on correct posture. Manual techniques to address joint mobility deficits may be used in any of the involved areas. It is not uncommon for structures in the upper body that are restricted and or weak to adversely influence symptoms at the hand and wrist and place tension on the nervous system.
Other non-operative treatment includes activity modification. Your physical therapist can work with you on ways to make these adjustments in your specific work and daily activities.
Avoiding prolonged, forceful, repetitive grasp activity
Optimize grip circumference of tools using ergonomic handles, foam insulation/padding. Limit direct pressure on palm/carpal tunnel region
Use of neutral wrist with activity
Quick stretch breaks-postural awareness/stability
Use of padded anti-vibration gloves (cycling gloves work well)
Use good posture with daily activities
If you end up needing surgery for carpal tunnel syndrome, many of the same contributing factors should be treated to prevent recurrence. In addition, therapy will work on managing scar tissue development and sensitivity, re-establishing grip, pinch and upper body strength, and address your specific needs for returning to normal activity. Many hand surgeons do not regularly refer patients for physical therapy after a carpal tunnel release but you may request this or refer yourself to our Certified Hand Therapist, Amy Houchens, by calling (541) 388-2681.