Fig. 8. Histograms of frame-wise difference between motion analysis and inertial sensor x, y and z displacements after high-pass filtering. Histograms are shown for (A) walk (1.4 m s^-1), (B) trot (3.5 m s^-1) and (C) left lead canter (9.0 m s^-1). The reduced spread of the histograms (compared with the unfiltered displacement error histograms in Fig. 7) demonstrates the ability of the inertial sensor integration process to capture the cyclical components of the displacements.