Abstract
Background With emerging interest in exercise and lifestyle interventions for children and adolescents with spina bifida, there is a need for appropriate measurements in exercise testing.
Objective The purpose of this study was to assess both reliability and agreement of maximal and submaximal exercise measures in “normal ambulatory” and “community ambulatory” children and adolescents with spina bifida.
Design This was a reproducibility study.
Methods Twenty-three children and adolescents with spina bifida (10 normal ambulatory and 13 community ambulatory) participated in the study. Maximal exercise outcomes were measured using a graded treadmill test. Peak measures (peak oxygen uptake [V̇o2peak], peak heart rate [HRpeak], heart rate response [HRR], and oxygen pulse) were recorded. For submaximal measures, heart rate (HR) and oxygen uptake (V̇o2) at the ventilatory threshold and oxygen uptake efficiency slope (OUES) were derived from the maximal measures. Functional performance was measured as the 6-minute walking distance and the maximal speed during the treadmill test. After checking for normality and heteroscedasticity, paired t tests, intraclass correlation coefficients (ICCs), and the smallest detectable difference (SDD) or the coefficient of variation (CV) were calculated.
Results Performance measures showed good reliability and agreement. For maximal measures, acceptable ICCs were found for all measures. For submaximal measures, only HR at the ventilatory threshold showed an ICC of less than .80. Agreement showed a CV of less than 10% for all measures, except for V̇o2 at the ventilatory threshold, HRR, and OUES.
Limitations Limitations of the study include missing data due to equipment failure. Furthermore, the outcomes were limited to normal ambulatory and community ambulatory children and adolescents with spina bifida.
Conclusions Both maximal and submaximal measures of exercise testing can be used for discriminative purposes in ambulatory children and adolescents with spina bifida. For evaluative purposes, HR measures are superior to V̇o2 measures, while taking into account the individual variation of 5% to 8%. The SDD was 0.5 km/h for peak speed and 36.3 m for 6-minute walking distance. Heart rate response, oxygen pulse, and OUES are not recommended in the evaluation of exercise testing in this population.
Footnotes
Mrs de Groot, Dr Takken, Dr Gooskens, Dr Schoenmakers, Dr Vanhees, and Dr Helders provided concept/idea/research report. Mrs De Groot, Dr Takken, Dr Schoenmakers, and Dr Vanhees provided writing. Mrs de Groot, Dr Takken, and Mrs Wubbels provided data collection and analysis. Mrs de Groot and Dr Vanhees provided project management. Mrs de Groot, Dr Takken, and Dr Helders provided fund procurement. Mrs de Groot, Dr Gooskens, Dr Schoenmakers, and Dr Helders provided participants. Dr Takken and Dr Helders provided facilities/equipment. Dr Gooskens, Dr Schoenmakers, Dr Vanhees, and Dr Helders provided institutional liaisons. Dr Takken, Dr Gooskens, Dr Schoenmakers, Dr Vanhees, and Dr Helders provided consultation (including a review of manuscript before submission).
The authors thank the children and their parents for their participation in this research. They also thank the students who participated as research assistants.
All study procedures were approved by the Utrecht University Medical Ethics Committee.
This study was part of the Utrecht Spina Bifida And Graded Exercise study (the USAGE study) and was financially supported by Stichting BIO-Kinderrevalidatie Arnhem, the Dutch Royal Society for Physiotherapy, the Wilhelmina Children's Hospital Research Fund, and the University of Applied Sciences, Utrecht, the Netherlands.
- Received February 17, 2010.
- Accepted November 1, 2010.
