Figure 1.

The timing identifications using three different detection methods. The vertical solid and dotted lines in each panel show the foot contact and foot-off timing, respectively. We calculated the stance time by computing the duration of the foot contact and foot-off for each skating stroke (intervals within horizontal arrows). (A) Kinetic detection using the foot pressure. The horizontal dotted line indicates the threshold level (20% peak) for the identification of foot contact and foot-off. (B) Acceleration detection using the sagittal foot acceleration. Gray line: raw sagittal acceleration. Red line: high-pass filtered sagittal acceleration. Blue line: low-pass filtered sagittal acceleration. (C) Integrated detection using both the foot sagittal acceleration and the knee flexion angle.