The 6-Minute Stepper Test cannot be used to assess the functional exercise capacity in healthy children from 6 to 12 Years Old

Abstract

Background: Assessing functional exercise capacity in children became important. This capacity may be assessed by different tests including submaximal test. The gold standard submaximal test in children is the six-minute walking test (6MWT). The main aim of this study was to establish the concurrent validity of the 6-minute stepper test (6MST) to assess the functional exercise capacity. The secondary objectives were to compare the change in cardio respiratory parameters between 6MST and 6MWT, and to determine the feasibility of the 6MST in healthy children.

Methods: 53 healthy children were included in this cross-over randomized controlled trial. Subjects underwent in a random order the 6MST and 6MWT. The primary outcome was the number of steps during 6MST and the 6-minute walking distance (6MWD). The secondary outcomes were the pulse oxygen saturation and heart rate.

Results: 6MWD and number of steps were not correlated (r=0.103; p=0.46). There was a significantly greater increase (p<0.001) in pulse heart rate values during the 6MWT than the stepper test (46.8 ± 17.5% vs 31.1 ± 18.3%). Moreover, no correlation between heart rate differences was found in both tests (r=0.139; p=0.32). Pulse oxygen saturation was clinically unchanged in both tests. All children were able to perform the 6MST completely.

Conclusion: We could not demonstrate the concurrent validity of the 6MST to assess the functional exercise capacity. Moreover, 6MST and 6MWT have different cardio-pulmonary demands. However, we found that the 6MST is feasible in healthy children from 6 to 12 years old.