title: Surface electromyography of wrist flexors and extensors in children with hemiplegic cerebral palsy.
abstract: OBJECTIVE
  To investigate the characteristics of motor unit recruitment and coordination function of the wrist during maximum isometric voluntary contraction (MIVC) using surface electromyography (EMG) in children with hemiplegic cerebral palsy (CP).
  
  
  METHODS
  A cross-sectional trial.
  
  
  METHODS
  Hospital neurology and rehabilitation department.
  
  
  METHODS
  Sixty-eight children with spastic hemiplegic CP.
  
  
  METHODS
  The signals of wrist flexors and extensors in unaffected and affected hands of children with hemiplegic cerebral palsy were measured with surface EMG. The characteristics of integrated EMG (iEMG), root mean square (RMS), and co-contraction ratio of surface EMG were analyzed.
  
  
  RESULTS
  The RMS and iEMG in the affected hand during MIVC were higher than that of the unaffected hand (P < .001). The RMS and iEMG of wrist extensors and the iEMG of wrist flexors of the affected hand had a good correlation with the unaffected hand (P < .01). The RMS and iEMG of the unaffected hand during MIVC were higher than that of the affected hand (P < .001), and the iEMG of the unaffected hand had a good correlation with the affected hand (P < .05). The RMS and iEMG in the unaffected hand during MIVC were significantly higher than that of the affected hand during MIVC (P < .001). The co-contraction ratio of the unaffected hand was significantly lower than that of the affected hand (P < .001).
  
  
  CONCLUSIONS
  The affected side shows more co-contractions than the unaffected side in children with hemiplegic CP. However, the unaffected side demonstrates stronger motor unit recruitment at maximal effort than the affected side. In addition, this study demonstrates the successful use of surface EMG for assessment of motor unit activation in young children with CP.
authors.affiliation: Department of Neurology and Rehabilitation, Guangzhou Women and Children's Medical Center, Guangzhou 510120, China(∗). Electronic address: xksyi@126.com.
authors.forename: Kaishou
authors.initials: K
authors.lastname: Xu
authors.affiliation: Department of Neurology and Rehabilitation, Guangzhou Women and Children's Medical Center, Guangzhou 510120, China(†).
authors.forename: Jianning
authors.initials: J
authors.lastname: Mai
authors.affiliation: Department of Neurology and Rehabilitation, Guangzhou Women and Children's Medical Center, Guangzhou 510120, China(‡).
authors.forename: Lu
authors.initials: L
authors.lastname: He
authors.affiliation: The Affiliated Women and Children's Medical Center of Guangzhou Medical University, Guangzhou 510120, China(§).
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Yan
authors.affiliation: The Affiliated Women and Children's Medical Center of Guangzhou Medical University, Guangzhou 510120, China(¶).
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D002547:Cerebral Palsy / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006429:Hemiplegia / Q000503:physiopathology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology; D011999:Recruitment, Neurophysiological / Q000502:physiology*; D014953:Wrist