Alteration in cardiovascular and postural control relationship in non-fainting elderly individuals

It is known that standing induces orthostatic stress on the cardiovascular system. Our previous works have presented that the postural control during standing and cardiovascular changes are related to each other in the health young individuals. However, it remains to be checked if such a relationship is present in the elderly individuals as well. The present study conducted experiments similar to our previous studies and collected data for the muscle activation in lower leg muscles along with blood pressure during a passive stand test. Application of wavelet transform coherence method provided time frequency distribution of the coherence between the two signals. High coherence (>threshold) was observed between the two signals suggesting a strong relationship. Additionally, a frequency dependent behavior was observed between the two signals. The results from this study present strong evidence that there is a change in the relationship between the two signals with aging.