Upper extremity muscle activation in children with unilateral cerebral palsy during an auditory cued repetitive task: Effects on bimanual coordination.

PURPOSE

The aim of this exploratory study was to investigate mirror muscle activation in the upper limbs of children with unilateral cerebral palsy during an auditory-cued repetitive squeezing task and to compare upper limb muscle activation patterns to typically developing peers engaged in the same task.

METHODS

A convenience sample of six children with unilateral cerebral palsy and six typically developing peers (7-17 y) participated in the study. Muscle activity was measured using a 16 channel Zerowire EMG system (Noraxon, USA Inc. Scottsdale, AZ) in the anterior deltoid, biceps brachii, extensor carpi radialis, flexor carpi radialis, and lateral triceps muscles bilaterally as children squeezed a pediatric bulb dynamometer to 3 pounds per square inch (PSI) for a one second duration, 10 times in one minute. Squeezing activity was cued by a computer generated auditory beep. Between hand differences in muscle onset times and onset amplitude for each muscle were determined using paired t-tests. Two group by two hand ANOVA measured between group differences.

RESULTS

Results supported increased later muscle onset and lack of significant differences in onset amplitude bilaterally when the dominant hand was working in the CP population.

CONCLUSIONS

There are differences in motor control mechanisms of muscle activation between populations.