Sample entropy-based analysis of differential and traditional training effects on dynamic balance in healthy people

The authors applied algorithms based on the sample entropy (SampEn) measurements to analyze the evolution of regularity in center of pressure displacements on the medialateral (ML) and anteroposterior (AP) axes after the application of 2 balance training methods: differential and traditional. A total of 14 young healthy participants took part in this study undertaking 5 SampEn measurements, a pre- and posttest, and 3 retests on dynamic balance and monopodal support. Results show a SampEn increase in the ML axis over the medium term (4 weeks) with both training methods. Over the short term (1 week), only traditional training shows a SampEn increase in the ML axis. In the AP axis, the traditional training method also shows a SampEn increase over the medium and short terms. A higher irregularity of the COP displacements is also present in the same axis, far from the higher regularity observed in the AP axis. These findings suggest a variability strategy related with the postural control during supports.