Down-sampling

As the frequency of ViMove data was generally slightly lower than 20 Hz and not constant between recordings, the individual sample frequency for each movement direction in each participant was estimated. This was performed by identifying the spike in both recordings and identifying an identical measurement characteristic point in both the graphed datasets after the third movement repetition. Then the time between these two data points was calculated. This gave an estimation of the actual ViMove sample rate (assuming that the Vicon sample rate was constant at 200 Hz) and that sample rate was used to down-sample the Vicon data to the estimated ViMove sampling rate and allow these two sets of angular data to be merged. The mean estimated sampling frequency for ViMove was 19.6 Hz (full range 19.0–19.8 Hz).