Differences in Exercise Effects from Static versus Dynamic Standing in Non-Ambulatory Children with Cerebral Palsy

Abstract

PURPOSE: To compare the metabolic adaptive effects to four months of two types of structured training regimes, static standing (StS) versus dynamic standing (DyS), on cardiopulmonary and metabolic parameters among non-ambulatory children with cerebral palsy (Na-CP). METHODS: Eighteen Na-CP participated in an exercise intervention study with a crossover design, comparing four months of StS to four months of DyS. During StS, the Na-CP were encouraged to exercise according to standard care recommendations in Sweden including daily supported StS for 30-90 minutes. During DyS, daily exercise for at least 30 minutes at a speed between 30 to 50 rpm in an Innowalk (Made for movement, Norway) was recommended. We assessed adaptive effects from the exercise programs through indirect calorimetry during 30 minutes of StS and DyS. Exercise test to evaluate StS was performed in a standing frame and to evaluate DyS using an Innowalk (Made for movement, Norway). An airtight mask covering the mouth and nose was worn in order to measure breath-by-breath VO2, VCO2 and VE (Oxycon Mobile, Jaeger, Germany). Heart rate was recorded continuously throughout the test (Polar T1, Polar, Finland). As many of the variables were linearly correlated, we used robust Principal Component Analysis (rPCA) to determine the components carrying most information. A multidimensional Shapiro-Wilk test indicates that the data can be well described as being multivariate normal distributed, allowing the use of a Hotelling T2 test. RESULTS: In a multidimensional statistical analysis of metabolic exercise effects, oxygen consumption, carbon dioxide production, and ventilation were concluded to carry most information and additionally, seen to be statistical different between StS and DyS reviling a p-value for the two groups having different means of 4.6 *10-5. CONCLUSIONS: A highly statically significant difference was found in the metabolic adaptation, described as VO2, VCO2 and VE, to StS versus DyS.Figure.: Shows the two most relevant components (rpc1 and rpc2), computed using Robust PCA (RPCA). The dark points are the differences of the second and first measurement for StS, the lighter points, are the same difference for DyS. A multidimensional Shapiro-Wilk test was used to define the 95% confidence level ellipses to be drawn.