title: Impact of muscle activation on ranges of motion during active elbow movement in children with spastic hemiplegic cerebral palsy.
abstract: BACKGROUND
  Children with spastic hemiplegic cerebral palsy are restricted in their daily activities due to limited active ranges of motion of their involved upper limb, specifically at the elbow. Their impaired muscles are frequently targeted by anti-spastic treatments that reduce muscle tone. But these treatments do not necessarily improve the limb function. There is a lack of comprehensive knowledge of the quantitative relations between muscle activation and joint active ranges of motion. Consequently, the objective of this study is to quantify the impact of muscle activation on the elbow active ranges of motion.
  
  
  METHODS
  During voluntary elbow pronation/supination and extension/flexion movements, kinematic and electromyographic measurements were collected from the involved upper limb of 15 children with spastic hemiplegic cerebral palsy (mean age=8.7 years, standard deviation=2.2) and the dominant upper limb of 15 age-matched children who are typically developing. Representative indicators of the muscle activation, such as the muscle co-activation, were extracted from the electromyographic measurements.
  
  
  RESULTS
  Muscle co-activation in the involved upper limb accounted for 78% and 59% of the explained variance of the supination and extension limited active ranges of motion respectively. The agonist and antagonist muscle activations were both longer in the involved upper limb.
  
  
  CONCLUSIONS
  This study succeeded in quantifying the impact of longer antagonist muscle activation on decreased elbow active ranges of motion in children with spastic hemiplegic cerebral palsy. Longer agonist muscle activation suggests that strengthening agonist muscles could increase the extension and supination ranges of motion, which constitutes a perspective of future clinical studies.
authors.affiliation: Research Centre, CHU Sainte-Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montreal, Quebec, Canada; Department of Mechanical Engineering, Polytechnique Montréal, 2500 Chemin de Polytechnique, Montreal, Quebec, Canada. Electronic address: aurelie.sarcher@polymtl.ca.
authors.forename: A
authors.initials: A
authors.lastname: Sarcher
authors.affiliation: Research Centre, CHU Sainte-Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montreal, Quebec, Canada; Department of Mechanical Engineering, Polytechnique Montréal, 2500 Chemin de Polytechnique, Montreal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Raison
authors.affiliation: Research Centre, CHU Sainte-Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montreal, Quebec, Canada; Department of Kinanthropology, Université du Québec à Montréal, C.P. 8888, succursale Centre-Ville, Montreal, Quebec, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Ballaz
authors.affiliation: Research Centre, CHU Sainte-Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montreal, Quebec, Canada; Department of Kinanthropology, Université du Québec à Montréal, C.P. 8888, succursale Centre-Ville, Montreal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Lemay
authors.affiliation: Laboratoire d'analyse du Mouvement, Pôle Médecine Physique et Réadaptation, hôpital Saint Jacques, CHU Nantes, Nantes, France.
authors.forename: F
authors.initials: F
authors.lastname: Leboeuf
authors.affiliation: Marie Enfant Rehabilitation Centre, 5200 Bélanger, Montreal, Quebec, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Trudel
authors.affiliation: Research Centre, CHU Sainte-Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montreal, Quebec, Canada; Institute of Biomedical Engineering, Université de Montréal, 2960 Chemin de la Tour, Montreal, Quebec, Canada.
authors.forename: P A
authors.initials: PA
authors.lastname: Mathieu
mesh_terms: D001696:Biomechanical Phenomena; D002547:Cerebral Palsy / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004550:Elbow / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D009128:Muscle Spasticity / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology; D034941:Upper Extremity / Q000503:physiopathology
keywords: Cerebral palsy; Co-activation; Electromyography; Extension/flexion; Functional evaluation; Kinematics; Pediatrics; Pronosupination; Rehabilitation; Upper limb