title: Evaluation of the catch in spasticity assessment in children with cerebral palsy.
abstract: OBJECTIVE
  To evaluate whether the catch in clinical spasticity assessment in cerebral palsy (CP) is the consequence of a sudden velocity-dependent increase in muscle activity, resulting from hyperexcitability of the stretch reflex in spasticity.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A special school for children with physical disabilities.
  
  
  METHODS
  Children with CP (N=20; age range, 5-14y; mean weight +/- SD, 35+/-14kg; mean length +/- SD, 139+/-19cm).
  
  
  METHODS
  Spasticity assessment tests (using slow and fast passive stretch) were performed in the medial hamstrings, soleus, and medial gastrocnemius muscles of the children by 2 experienced examiners.
  
  
  METHODS
  Surface electromyography (EMG) was recorded and joint motion was simultaneously measured using 2 inertial sensors. The encounter of a catch by the examiner was compared with the presence of a sudden increase in muscle activity ("burst"). The average rectified value (ARV) of the EMG signal was calculated for each test.
  
  
  RESULTS
  The study shows a sudden increase in muscle activity in fast passive stretch, followed by a catch (hamstrings 100%, soleus 95%, gastrocnemius 84%). The ARV in slow passive stretch was significantly lower.
  
  
  CONCLUSIONS
  The results confirm that in children with CP, an increase in muscle activity is primarily responsible for a catch in fast passive muscle stretch.
authors.affiliation: Department of Rehabilitation Medicine, Research Institute MOVE, Vrije Universiteit University Medical Center, 1007 MB Amsterdam, The Netherlands. j.vandennoort@vumc.nl
authors.forename: Josien C
authors.initials: JC
authors.lastname: van den Noort
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Scholtes
authors.forename: Jules G
authors.initials: JG
authors.lastname: Becher
authors.forename: Jaap
authors.initials: J
authors.lastname: Harlaar
mesh_terms: D000293:Adolescent; D002547:Cerebral Palsy / Q000503:physiopathology* / Q000534:rehabilitation; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D009128:Muscle Spasticity / Q000503:physiopathology* / Q000534:rehabilitation; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010808:Physical Examination; D026741:Physical Therapy Modalities; D012026:Reflex, Stretch