Differentiating characteristics of EMG signals in pediatric muscle tone disorders in the aspect of evaluating postural control

Background and Objective: Abnormalities in muscle tone, such as postural hypotonia, can significantly affect motor development and postural control in children, often presenting with unclear origins and subtle clinical manifestations. These disturbances may also be associated with broader musculoskeletal dysfunctions. The presented research aims to examine whether electromyographic signal analysis can support the objective evaluation of muscle tone abnormalities in children. Methods: Electromyography (EMG) signals were recorded from the sternocleidomastoid and rectus abdominis muscles during the Neck Flexor Endurance Test in 31 children. Time-domain and frequency-domain characteristics were analyzed using statistical methods to differentiate groups classified by physiotherapy experts. Machine learning methods were used to objectively verify the usefulness of the collected data in classification tasks. Statistical analysis included group comparison using Student's t-test or non-parametric Mann–Whitney U test, where applicable. Results: Compensatory mechanisms were observed in children with reduced muscle tone, with increased activation of the rectus abdominis muscles. EMG analysis revealed that the rectus abdominis muscles exhibited 25 statistically important features. Feature selection methods like RefielF presented the most differentiating set from sternocleidomastoid muscles (20 features). The Support Vector Machine showed the best overall performance (78.8%) with mean value data set. Conclusions: The EMG signal analysis revealed significant differences between children with reduced muscle tone and those with normal tone, emphasizing its clinical relevance for pediatric rehabilitation. The promising performance of the tested models suggests that this line of research may be warranted. These findings lay the groundwork for future work and underscore the need for further research on a larger sample to confirm and refine these observations.