Muscular Activation during Low Resistance Elbow's Motion of Children with and without Cerebral Palsy

Here we analyze the effects of load, contraction type, joint position and joint angular velocity on coordination of elbow's muscle activity during low resistance motion of children with and without cerebral palsy (CP) by joint position and velocity nonlinear categorization of surface electromyographic (sEMG) activity. Seven healthy children and four children with CP from 6 to 13 years old were assessed. Main and mixed effects for all conditions on sEMG activity were analyzed by ANOVA tests. Linear regressions for sEMG and joint angle velocity were calculated and the effects of group, load and muscle on the slope of linear regressions were analyzed by ANOVA tests. Observed muscular coordination for all test conditions ( , mean power of 80
^%
) agreed with previously reported muscular coordination of adults. Increased sEMG activity for CP children and high angular velocity were found. Children with CP showed differences on linear regression slopes (mean RMSE=0.07 and mean R2=0.06) during fine-tuning control tasks for biceps and triceps medialis. In this study we found evidence based on a time domain analysis of muscular activity which helps to confirm the presence of a common muscle coordination mechanism previously suggested to be present in healthy children. Also, we found novel evidence to support the idea that this control is altered in children with neuromuscular conditions such as CP. This information may be useful for diagnosis and treatment of neuromusculoskeletal conditions in children.