Fig. 2
From: Automatic detection of human gait events: a simple but versatile 3D algorithm
GRF cannot be used as a gold standard to specify the four calibration parameters for the Multi-Condition algorithm. GRF-based Foot Off (grey circle on the GRF dashed curve) is delayed by seven frames compared to Multi-Condition-based Foot OFF (orange circle on Hallux Antero-Posterior position solid curve). The green, blue and red vertical lines on the graph represent three instants illustrated with the same colour code in the picture