Changes in pain, disability, and muscle activation patterns in chronic whiplash patients after ambulant myofeedback training

Objective: The aim of this exploratory study was to investigate changes in pain, disability, and muscle activation patterns in patients with chronic whiplash-associated disorder (WAD) after 4 weeks of myofeedback training. Methods: Eleven WAD patients received-ambulatory myofeedback training, during which upper trapezius muscle activation and relaxation were continuously recorded and processed for 4 weeks. Feedback was provided when muscle relaxation was insufficient. Pain in neck, shoulders, and upper back (Visual Analogue Scale), disability (Neck Disability Index), and muscle activation patterns during rest, typing, and stress tasks (surface electromyography) were assessed before and after the 4 weeks of training. Results: Pain intensity decreased after 4 weeks of training. Clinically relevant changes were found with regard to pain in the neck and upper back region (55% of the patients), right shoulder (64%), and left shoulder (18%). A trend for decreased disability was found which was clinically relevant in 36% of the patients. A remarkable reduction was found in the Neck Disability Index items concerning headache and lifting weights. Overall, muscle activation was lower and muscle relaxation was higher after the training period with the largest differences during rest. Clinically relevant changes in surface electromyography parameters were found in a minority of patients. Conclusion: Four weeks of ambulant training may be beneficial in reducing pain and disability levels and normalizing muscle activation patterns in chronic WAD patients. A randomized-controlled study is recommended to further explore the effects of myofeedback training.