The authors regret that Eq. (1) in the methods section in the above paper to calculate the contributions of the CoP and counter-rotation mechanisms to the CoM acceleration differs from the equation used for the data analysis (and to make Fig. 3). The correct equation is: [Formula presented] This formula is based on Eq. (5) in Hof (2007). The data analysis and results are unaffected as the correct equation was used. In the methods we forgot to mention the definition of the coordinate system. The +x axis is defined to the left, the +y axis is defined as forward, and the +z axis is defined as upwards. The authors would like to apologise for any inconvenience caused.