Preview of Trigger Finger:
Trigger Finger is a form of overuse injury with symptoms ranging from a painless annoyance with occasional snapping/jerking of the finger(s), to severe dysfunction and pain with continuous locking of the finger(s) in a flexed downward position into the palm of the hand.
Anatomy of Trigger Finger:
The tendons that move the fingers are held in place on the bones by a series of ligaments called “pulleys”. These ligaments form an arch on top of the bone that creates a tunnel so that when the flexor muscles are contracted, the tendons can move along the bone in a straight path. In order to make sure these tendons travel in a smooth manner and reduce friction of the tendon and its sheath, the body produces and coats the flexor tendons with a slippery coating called “tenosynovium” which allows the tendons to glide through the tunnel formed by the pulleys when the fingers/hands are used to grasp objects.
Symptoms of Trigger Finger:
Trigger Finger may affect any of the fingers (1-5) as well as any one of the finger joints (MP, PIP, DIP Joints). The occurrence of this injury usually results from overuse of the flexor muscles/tendons and the formation of an adhesion or fibrotic nodule on the tendon. If left untreated, the adhesion/nodule becomes larger, therefore creating a conflicting ratio between the size of the tendon and the size of the entrance of the tendon sheath. There may also be thickening of the pulley ligament as well, due to the friction of the adhesion/nodule against the pulley ligament. In most cases, if the adhesion/nodule is not treated, it will continue to increase in size (Depending on activity/use of affected finger) to the point where it still has the ability to pass into and through the tendon sheath when flexing the finger, but becomes stuck and cannot move back through the tendon sheath and/or pulley when trying to extend/straighten the finger, thus causing the finger to lock in the flexed downward position (Palm of hand). At first, this is experienced as a snapping of the affected finger when relaxing a fist. If the condition worsens, the finger may need active force from the opposing hand/fingers to straighten, or the affected finger(s) may not straighten at all.
Cause(s) of Trigger Finger:
Most clinicians believe that the disorder is caused by the tendon sheath because it becomes thickened or swollen and pinches the tendon and prevents it from gliding smoothly. But common sense reveals that the history of patients suffering with Trigger Finger have one common denominator, overuse, excessive use and/or abuse of the hands from work and recreational activities.
Trigger Finger is usually (not always) the result of direct injury to the tendon via micro-tears resulting from direct and sudden trauma or tasks that required repetitive use of the hands over long periods of time. And as the body attempts to heal itself causes the formation of scar tissue / fibrotic adhesion, and the swelling of the tendon sheath is a secondary injury caused by friction between the adhesion and the tendon sheath as the finger is flexed and extended. This friction causes irritation, swelling, and inflammation to both the adhesion on the tendon and to the tendon sheath, thus resulting in a cyclic injury, starting with the adhesion on the tendon, then the adhesion irritates the sheath, then the sheath swells and pinches down more so it irritates the adhesion even more, and continuing to go back and forth again and again with both the tendon and its sheath contributing to the cause-effect of Trigger Finger.
NOTE: Other contributors/factors of Trigger Finger are Rheumatoid Arthritis, partial tendon lacerations, repeated trauma from pistol gripped power tools, or long hours grasping a steering wheel.
Trigger Finger may also be caused by an infection of the synovium, resulting in the scarring and formation of a nodule on the tendon. Trigger Finger can also be caused by a congenital defect that forms a nodule inside of the tendon. The condition is not usually noticeable until the infant begins to use its hands.
Treatment(s) for Trigger Finger:
Sometimes the swelling can be treated with rest, activity modification, oral anti-inflammatory medications, or steroid injections. The tendon sheath will usually return to its normal, pain-free condition. More severe cases may require surgery to release the tendon, but is suggested as a last resort after all other conservative methods have been attempted.
Often times, Trigger Finger will be persistent because either no rehabilitation efforts were attempted or improper forms of rehabilitation were utilized pre- or post-surgery. In most cases of Trigger Finger, injections and surgery both attempt to cure the disorder by treating the symptoms instead of treating the “Actual Injury”. In the case of Trigger Finger, the actual injury is the adhesion, nodule, and scar tissue buildup on the tendon due to excess strain, overuse, or direct trauma to that specific location on the tendon. Because Trigger Finger and those afflicted with Repetitive Strain Injuries, Cumulative Trauma Disorders, Including Carpal Tunnel Syndrome ALL HAVE THE SAME TYPE OF HISTORY (For the most part), this Trigger Finger would be treated in the same manner, through the implementation of a variety of stretching and strengthening exercises to break down adhesions, thin the tendon and create stability.
Successful Treatment for Trigger Finger: (Perform in the sequence listed)
- Transverse Friction Massage – Perform across the nodule/adhesion on the affected finger to help break it down, reducing its size.
- Stretches – Immediately follow Transverse Friction Massage with passive and active stretches to the affected finger to help thin the tendon.
- Exercises – Immediately follow the stretches with active strengthening exercises for the OPPOSING MUSCLE GROUP, in this case the extensor muscles that extend the fingers and wrist, in order to hold and maintain the length to the tendon that you just stretched
- Hydrotherapy – Ice the affected tendon in a stretched position to maintain the length of the tendon that was just created through the stretches and exercises. Icing the tendon also removes swelling and toxins created through the use of massage, stretches and exercises. Ice the tendon no longer than 1-2 minutes. Take a break for 3-minutes and repeat the ice cycle two more times.
Always consult a physician to make sure that you have had a proper diagnosis of your condition before beginning any form of treatment program.
Author: Jeff Anliker, LMT, is a Therapist and Inventor of Therapeutic Exercise Products that are utilized by Corporations, Consumers and Medical Facilities around the world for the prevention and rehabilitation of repetitive strain injuries.
Article reprinted courtesy of www.repetitive-strain.com.