title: Quantitative measurement of spasticity in children with cerebral palsy.
abstract: Spasticity was quantified in nine children with spastic diplegia, using a sinusoidal displacement of the foot at frequencies from 3 to 12Hz. Ankle-joint stiffness was separated into elastic (energy-storing) and viscous (energy-dissipating) components. 'Path length' was used to represent the variation in stiffness over this frequency range. Compared with 11 unaffected children, a significant difference in path lengths was demonstrated for the children with spasticity. An age-dependent effect was demonstrated when path lengths of unaffected children were compared with those of 10 unaffected adults. A modified path-length measure is proposed which minimizes age dependency, yet enables detection of spasticity. Passive stiffness properties of unaffected adults showed higher elastic stiffness, viscosity and friction than unaffected children. A method was developed to evade the need for temporary nerve blocks to calculate inerital properties of the foot in persons with spasticity.
authors.affiliation: Department of Rehabilitation Medicine, University of Washington School of Medicine, Seattle 98195.
authors.forename: R
authors.initials: R
authors.lastname: Price
authors.forename: K F
authors.initials: KF
authors.lastname: Bjornson
authors.forename: J F
authors.initials: JF
authors.lastname: Lehmann
authors.forename: J F
authors.initials: JF
authors.lastname: McLaughlin
authors.forename: R M
authors.initials: RM
authors.lastname: Hays
mesh_terms: D001696:Biomechanical Phenomena; D002547:Cerebral Palsy / Q000175:diagnosis* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009128:Muscle Spasticity / Q000175:diagnosis* / Q000503:physiopathology; D009132:Muscles / Q000294:innervation; D009460:Neurologic Examination / Q000295:instrumentation*; D016059:Range of Motion, Articular / Q000502:physiology; D012021:Reflex, Abnormal / Q000502:physiology; D012026:Reflex, Stretch / Q000502:physiology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*