Interpretation and implementation of oxygen uptake kinetics studies in children with spastic cerebral palsy

Abstract

From the scant data available, it seems that children with CP have a low maximum V̇2, a high O2 cost of submaximal exercise, and inefficient gait mechanics characterized by high levels of co-contraction. Despite the non-steady-state nature of habitual activity, there seem to be no published data focusing onV'o, kinetics in children with CP. Before measuringV̇2 kinetics, the noise content of the data needs to be examined because this has important implications for estimating τV̇2values. On the basis of the preliminary findings presented here, the breath-by-breath V̇2 responses of children with CP seem to have a similar noise magnitude to those of typically developing children; however, because they have smaller response amplitudes, the averaging of several repeated trials will be even more important than in typically developing children. Thorough habituation will be required to enable participants to complete the simulated step change exercise protocols that will enable V̇2kinetics to be quantified. To facilitate appropriate comparisons with control groups on the basis of relative exercise intensities, further work is needed to establish the efficacy of estimating TLac from gas exchange data in children with CP. By measuring V̇O2 kinetics in children with CP, it is hoped that we will not only gain valuable insights into their exercise intolerance, but we will also have an important tool for assessing the effects of interventions using submaximal, and therefore less strenuous, exercise.