title: Effects of weight resistance on the temporal parameters and electromyography of sit-to-stand movements in children with and without cerebral palsy.
abstract: OBJECTIVE
  The purpose of this study was to examine the differences in phase durations and electromyography between children with and without cerebral palsy during sit-to-stand movements with weight resistance.
  
  
  METHODS
  Fifteen children with cerebral palsy and 15 age-matched children with typical development were recruited. They performed sit-to-stand movements while wearing a vest with four different loads (none, low, moderate, and high). Three phases during sit-to-stand and electromyography of vastus lateralis, gluteus maximus, and medial hamstring were recorded.
  
  
  RESULTS
  The ascending phase and peak electromyography of vastus lateralis showed a significant interaction between groups and resistance conditions. The children with cerebral palsy took a longer time to stand up than the control group when the load was high (P = 0.004). The peak electromyography of vastus lateralis increased with increasing resistance in the control group (P < 0.017) but not in children with cerebral palsy. Children with cerebral palsy had a higher cocontraction ratio of the medial hamstring/vastus lateralis than the control group (P = 0.001) at all resistance levels.
  
  
  CONCLUSIONS
  Children with cerebral palsy took a longer time for the task but did not increase agonist contraction as the control group in response to higher loads. Future research is suggested to see whether agonist contraction will be improved with strengthening therapy.
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan, Republic of China.
authors.forename: Hua-Fang
authors.initials: HF
authors.lastname: Liao
authors.forename: Sue-Mei
authors.initials: SM
authors.lastname: Gan
authors.forename: Kwan-Hwa
authors.initials: KH
authors.lastname: Lin
authors.forename: Jiu-Jenq
authors.initials: JJ
authors.lastname: Lin
mesh_terms: D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000503:physiopathology / Q000534:rehabilitation*; D002648:Child; D004576:Electromyography; D006801:Humans; D007866:Leg / Q000502:physiology / Q000503:physiopathology; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology; D055070:Resistance Training; D016474:Weight-Bearing / Q000502:physiology