Influence of Posturographic Protocol on Postural Stability Sways During Bipedal Stance After Ankle Muscle Fatigue.

The aim of this study was to analyze the persistence of exercise-induced changes in postural stability and to verify if they last long enough to be captured by two sequential posturographic tests. The study, including 12 healthy young men (M age = 20.7 year, SD = 0.7), comprised two sessions (Sessions I and II). Each session included one physical exercise, along with two posturographic measurements taken prior to and after the effort, respectively. During Session I, open-eye test was followed by closed-eye test. This order was reversed during Session II, when closed-eye test was followed by open-eye test. The physical exercise protocol included repeated standing dual-heel raise until refusal. Regardless of the test order, markedly stronger effects of exercise-induced fatigue were documented during the first posturographic measurement. Only one reliable posturographic measurement can be taken if the fatigue protocol results in a short-term disruption of postural stability. The adverse effects of exercise-induced fatigue may no longer be observed during the subsequent test. As a result, the extent of post-exercise changes in postural stability may be underestimated leading to erroneous conclusions.