Supplementary Material for: Simultaneous Measurement of Breathing Kinematics and Surface Electromyography of Chest Wall Muscles during Maximum Performance and Speech Tasks in Children: Methodological Considerations

<b><i>Objective:</i></b> To develop a standardized paediatric protocol for acquiring simultaneous chest wall kinematics and surface electromyography (EMG) of chest wall muscles during maximum performance and speech tasks. <b><i>Patients and Methods:</i></b> Eighteen healthy participants included: (a) a younger age group (n = 6; ages 4.0-6.5 years), (b) an older age group (n = 6; ages 7.0-10.5 years), and (c) an adult group (n = 8; ages 21-33 years). A child (age 10 years) with spastic-type cerebral palsy (CP) served as a ‘proof of protocol feasibility'. Chest wall kinematics and surface EMGs (intercostals, rectus abdominus, external oblique, latissimus dorsi, and erector spinae) were acquired during maximum performance and speech tasks. <b><i>Results:</i></b> Successful calibration of the EMG signal and reliable detection of muscle activation onset, offset, and amplitude relative to vital capacity and percent maximum voluntary contraction in children were demonstrated. Kinematic and surface EMG measurements were sensitive to non-speech and speech tasks, age, and neurological status (i.e. CP). <b><i>Conclusion:</i></b> The simultaneous measurement of kinematics and EMG of the chest wall muscle groups provides a more comprehensive description of speech breathing in children. This protocol can be used for the observation and interpretation of clinical outcomes seen in children with motor speech disorders following treatments that focus on increasing overall respiratory and vocal effort.