Objective measures of dyskinesia: Towards a better understanding of the neuromotor control in children with dyskinetic cerebral palsy

Dyskinetic cerebral palsy is characterised by variable involuntary movements resulting in sustained twisting and jerky movements often causing functional limitations. Assessing dyskinesia using observation-based clinical tools with sufficient reliability and sensitivity can be challenging. However, accurate assessment of dyskinesia is necessary for effective management and development of novel therapies to treat dyskinesia in children with cerebral palsy. In this dissertation, techniques in motion analysis are investigated to explore objective methods that can detect, differentiate and grade the severity of dyskinesia in children with cerebral palsy. In addition, mobile tools such as inertial measurement units are investigated as a possible strategy to address concerns in clinical translation. Three upper limb activities were performed by six typically developing children and twelve children with cerebral palsy. Upper limb movements were recorded using a marker-based optoelectronic motion capture system, inertial measurement units and electromyography. Features of kinematic joint angles, joint centre trajectories and muscle activity were extracted and analysed against clinical assessments of dyskinesia. Kinematic studies using a marker-based optoelectronic system are recommended over inertial measurement units and electromyography for assessing dyskinesia in children with cerebral palsy. Features of volitional and non-volitional movement identified differences between typically developing upper limbs and upper limbs with dyskinesia, albeit more consistently across activities on the non-volitional side. In contrast, differentiating upper limbs with spasticity from dyskinesia in children with cerebral palsy was challenging with only a small number of features demonstrating significant differences. Finally, kinematic-based objective measures capturing smoothness of movement during the reach-and-hold activity provided the best prospect of assessing the severity of dyski