Aberrant learning in individuals who perform repetitive skilled hand movements: Focal hand dystonia—Part 1

Summary 

Stressful, repetitive use of the upper limb in work, sports, or musical performance can lead to acute, pain and loss of function. The evidence for tissue mircrotrauma as the underpinnings of this pain is convincing and explains why rest, anti-inflammatory medications, change in movement biomechanics and good ergonomics are usually effective treatment modalities. Unfortunately, some repetitive strain injuries become chronic with degenerative changes found in tendons and muscles, scarring restricting soft tissue and joint mobility and compression of peripheral nerves causing strain and limiting excursion. In other cases, involuntary co-contractions of flexors and extensors lead to painless, uncontrollable, end range twisting movements that interfere with the performance of target tasks. This movement dysfunction is referred to as occupational hand cramps, focal hand dystonia (FHd), golfers yip, keyboarders cramps, or musician's cramps. Research studies report evidence of degradation of the somatosensory, sensorimotor and motor representation of the hand in animals and patients with dystonic hand movements. This aberrant learning requires learning based training to reorganize the brain. In this presentation, the principles of neuroplasticity will be related to the origin, diagnosis, assessment and treatment of FHd grounded on an evidence-based review of the research to support aberrant learning as one etiology for the origin of this disorder and the foundation for a learning based approach to remediate the condition.

Keywords: Repetitive use, Microtrauma, Abberant learning, Focal hand dystonia, Occupational hand cramp