Generalizability of center of pressure measures of quiet standing

The test–retest reliability of centre of pressure measures in bipedal static task conditions – A systematic review of the literature

“…It has been shown that COP mean displacement velocity and path length were 26.1% greater when sampling frequencies of 50Hz were used compared to 10Hz [30] as it would be expected with more data points describing the shape of the COP. This however, did not significantly affect reliability as mean velocity showed generally consistent reliabilities (r=0.82-0.89) across different frequencies ranging from [27, 38,39] (Table 3).…”

“…This has later been disputed by studies investigating multiple time intervals of up to 120sec. They concluded that between 90 and 120sec are necessary to reach correlation coefficients of ≥0.75 for most COP parameters with confidence [15,22,38], further lengthening trial duration once an acceptable level is reached did not significantly reduce variability [9].…”

“…In the literature, sampling frequencies ranging from have been reported [9,16,17,22,27,[37][38][39][40][41] and it seems that the reported variations in COP reliability across similar experimental setups are at least partially due to the different frequencies chosen.…”

“…Furthermore, it has been stated that averaging two [35], three [24], four [38] or seven [17] trials yields acceptable reliability for the majority of COP parameters.…”

“…While the evaluation of COP excursions is a commonly used method for measuring postural stability [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] no standardization of this method exists. Further, the reliability of COP needs to be determined if studies using this method are to be considered valid.…”