title: Muscle synergy analysis in children with cerebral palsy.
abstract: OBJECTIVE
  To explore the mechanism of lower extremity dysfunction of cerebral palsy (CP) children through muscle synergy analysis.
  
  
  METHODS
  Twelve CP children were involved in this study, ten adults (AD) and eight typically developed (TD) children were recruited as a control group. Surface electromyographic (sEMG) signals were collected bilaterally from eight lower limb muscles of the subjects during forward walking at a comfortable speed. A nonnegative matrix factorization algorithm was used to extract muscle synergies. In view of muscle synergy differences in number, structure and symmetry, a model named synergy comprehensive assessment (SCA) was proposed to quantify the abnormality of muscle synergies.
  
  
  RESULTS
  There existed larger variations between the muscle synergies of the CP group and the AD group in contrast with the TD group. Fewer mature synergies were recruited in the CP group, and many abnormal synergies specific to the CP group appeared. Specifically, CP children were found to recruit muscle synergies with a larger difference in structure and symmetry between two legs of one subject and different subjects. The proposed SCA scale demonstrated its great potential to quantitatively assess the lower-limb motor dysfunction of CP children. SCA scores of the CP group (57.00 ± 16.78) were found to be significantly less (p < 0.01) than that of the control group (AD group: 95.74 ± 2.04; TD group: 84.19 ± 11.76).
  
  
  CONCLUSIONS
  The innovative quantitative results of this study can help us to better understand muscle synergy abnormality in CP children, which is related to their motor dysfunction and even the physiological change in their nervous system.
authors.affiliation: Department of Electronic Science and Technology, University of Science and Technology of China (USTC), Hefei, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Tang
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Shuai
authors.initials: S
authors.lastname: Cao
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: De
authors.initials: D
authors.lastname: Wu
authors.forename: Xiang
authors.initials: X
authors.lastname: Chen
mesh_terms: D002547:Cerebral Palsy / Q000150:complications / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004576:Electromyography / Q000379:methods; D005260:Female; D005684:Gait; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009135:Muscular Diseases / Q000209:etiology / Q000503:physiopathology*; D004856:Postural Balance; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013647:Task Performance and Analysis; D055815:Young Adult