Notice of RetractionThe Relationship between COP and COM during Upright Stance with Ankle Fixation

Center of pressure (COP) excursion is often used to quantify the stability of standing balance in clinical and experiments, but in fact, the stand balance is determined by maintaining the center of mass (COM) of body within the base of support. As ankle fixation will change the mechanism of keeping standing balance, the relationship between COP and COM may also be changed. On the purpose of discussing whether COP can still be used to assess the stability of standing balance with ankle fixed, this study employed a method for simultaneous measurement of COP and COM to acquire 10 subjects' standing balance data. Then we analyzed the difference between COP and COM during standing with or without ankles fixation. We found there are some differences and the correlation between COP and COM decreased. Therefore, we suggest these differences should be considered when COP is used to quantify the balance stability of postures with ankle fixation.