title: Impaired gait function in adults with cerebral palsy is associated with reduced rapid force generation and increased passive stiffness.
abstract: OBJECTIVE
  It is still not clarified whether spasticity contributes to impairments of gait function. Here we compared biomechanical measures of muscle weakness and stiffness of ankle muscles to impairments of gait function in adults with cerebral palsy (CP).
  
  
  METHODS
  Twenty-four adults with CP (mean age 34.3, range 18-57 years) and fifteen healthy age-matched controls were biomechanically measured for passive and reflex-mediated stiffness of the ankle plantarflexors at rest, maximal voluntary plantarflexion and dorsiflexion effort (MVCpf,df) and rate of force development (RFDpf,df). Kinematic analysis of the ankle joint during treadmill walking was obtained by 3-D motion analysis.
  
  
  RESULTS
  Passive stiffness was significantly increased in adults with CP compared to controls. Passive stiffness and RFDdf were correlated to reduced toe lift. RFDpf provided the best correlation to push-off velocity, range of movement in the ankle joint and gait speed. Reflex-mediated stiffness was not correlated to any parameters of impaired gait.
  
  
  CONCLUSIONS
  Impaired gait function in adults with CP is associated with reduced RFD and increased passive stiffness of ankle muscles.
  
  
  CONCLUSIONS
  These findings suggest that reduced rapid force generation and increased passive stiffness of ankle muscles rather than increased reflex-mediated stiffness (spasticity) likely contributes to impaired gait function in adults with CP.
authors.affiliation: Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark. Electronic address: ssgeertsen@nexs.ku.dk.
authors.forename: Svend Sparre
authors.initials: SS
authors.lastname: Geertsen
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark; Helene Elsass Center, Charlottenlund, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Kirk
authors.affiliation: Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; Helene Elsass Center, Charlottenlund, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Lorentzen
authors.affiliation: Helene Elsass Center, Charlottenlund, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Jorsal
authors.affiliation: Helene Elsass Center, Charlottenlund, Denmark.
authors.forename: Claus Bo
authors.initials: CB
authors.lastname: Johansson
authors.affiliation: Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark; Helene Elsass Center, Charlottenlund, Denmark.
authors.forename: Jens Bo
authors.initials: JB
authors.lastname: Nielsen
mesh_terms: D000293:Adolescent; D000328:Adult; D000843:Ankle Joint / Q000502:physiology; D002547:Cerebral Palsy / Q000175:diagnosis* / Q000503:physiopathology*; D004576:Electromyography / Q000379:methods; D005260:Female; D005684:Gait / Q000502:physiology*; D020233:Gait Disorders, Neurologic / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009129:Muscle Tonus / Q000502:physiology*; D014033:Toe Joint / Q000502:physiology; D055815:Young Adult
keywords: Cerebral palsy; Contractures; Gait function; MVC; RFD; Spasticity