To test the effect of different neck training methods on motor evoked potentials (MEPs) from the trapezius muscle. We hypothesized that training of the trapezius muscle would significantly increase MEPs, indicating facilitation of the corticomotor pathways. Additional experiments investigated the influence of muscle strength, muscle fatigue, and correlations between MEP amplitudes and behavioral aspects of motor learning.
Transcranial magnetic stimulation (TMS) was used to elicit MEPs from the trapezius muscle and the abductor pollicis brevis (APB) muscle in 60 healthy subjects in three conditions: (1) specific trapezius training, (2) coordination training of the neck, and (3) no training.
Specific training yielded an increase in MEPs 1 h (p = 0.001) and 7 days (p = 0.001) after training compared with baseline; no significant changes were seen after coordination training or no training. MEPs from the APB muscle did not change over time in any of the conditions. Muscle strength increased by 8% after specific training, but no subjective or objective measures of fatigue were observed.
The results showed that only specific training significantly increased trapezius MEPs for up to 7 days, indicating facilitation of the corticomotor pathways. These findings may help improve the future clinical management of neck pain.
© 2012 Scandinavian Association for the Study of Pain