Use of surface electromyography (EMG) in the diagnosis of childhood hypertonia: a pilot study.

In children, increased tone in a joint can be caused by spasticity, dystonia, rigidity, or mechanical limitations such as contracture. Determination of the cause of hypertonia is important for selection of appropriate therapy, but distinction between the types of hypertonia is difficult in a clinical setting. We present results of a pilot test of the use of a portable surface electromyography (EMG) device for the evaluation of hypertonia. Seven children 5-17 years of age with hypertonia due to cerebral palsy were each examined by 6 clinicians, both with and without the use of surface EMG. The use of surface EMG resulted in an increase in interrater agreement as well as an increase in the self-reported confidence of the clinicians in their assessment. These results support the importance of further testing of surface EMG as an adjunct to the clinical examination of childhood hypertonia.