Frequency content of standard posturographic measures - biomed 2013

Although still considered experimental by some, computerized posturography is becoming more and more the standard assessment of balance and neuromuscular control mechanisms while standing. However, there is no consensus as to the data acquisition parameters to be used. Depending on which posturography school one belongs to, acquisition frequencies vary from a few Hz all the way to 1 kHz, and little attention is usually given to the post-sampling filter cut-off frequency (implemented either in the hardware or in the software used to acquire the data), often without realizing the consequences such choices will have on the results. But the sampling and the filter cut-off frequencies are particularly important when dealing with spectral analysis or when secondary measurements such as the center of pressure coordinates, sway path length, velocity or acceleration are calculated from the measured forces and moments. In this paper, frequency content of vertical ground reaction force and center of pressure path coordinates excursion were determined for 946 subjects of both genders, with various age, height, body type, health status and nationality. The results of this spectral analysis made it possible to draw some general conclusions as to what should be a proper acquisition frequency for posturographic data.