title: Quadriceps and hamstring strength changes as a function of selective dorsal rhizotomy surgery and rehabilitation.
abstract: OBJECTIVE
  Objective measures of strength in children with cerebral palsy (CP) are needed to determine the effect that selective dorsal rhizotomy surgery (SDR) and subsequent rehabilitation have on muscle strength. This investigation quantified quadriceps and hamstring strength in children with CP pre-SDR and eight months post-SDR.
  
  
  METHODS
  Nineteen children with CP and 20 children without disabilities (WD group) were tested with an isokinetic dynamometer. The children performed a maximum concentric contraction of the quadriceps muscles as the dynamometer moved the knee from a flexed position to an extended position at 10 degrees per second. A maximum concentric contraction of the hamstring muscles was then performed as the knee was moved from extension to flexion. Four variables were recorded from the torque-angle data; peak extension and flexion torque and extension and flexion work.
  
  
  RESULTS
  Children with CP, both pre- and post-SDR were significantly weaker in all strength measures compared with the WD group. Children with CP post-SDR and rehabilitation had significantly greater peak torque and work values compared with their pre-SDR values. The results agreed with previous studies indicating that children with CP are weaker than their peers without disabilities. Previous studies on strength changes after SDR remain controversial.
  
  
  CONCLUSIONS
  The results of this study showed a significant increase in strength at the knee after rhizotomy and rehabilitation.
authors.affiliation: Human Performance Laboratory (S.A.R., J.R.E., K.S.O), Barnes-Jewish and St. Louis Children’s Hospital, St. Louis, Mo; Washington University School of Medicine and St. Louis Children’s Hospital (T.S.P., J.R.E), St. Louis, Mo.
authors.forename: S A
authors.initials: SA
authors.lastname: Ross
authors.forename: J R
authors.initials: JR
authors.lastname: Engsberg
authors.forename: K S
authors.initials: KS
authors.lastname: Olree
authors.forename: T S
authors.initials: TS
authors.lastname: Park