Fig. 1From: Quantification of gait parameters in freely walking rodentsOptical footprint detection system. a Schematic of the fTIR effect. LED light sources are located at the edges of a piece of acrylic glass and light propagates within the glass via internal reflection. Footprints disrupt this optical effect leading to the light scattering, which is detected by a high-speed camera. Single frame of an fTIR video in black and white (b) and color (b'). The fTIR effect is visible while the legs are in contact with the acrylic glass surface during the stance phase. Background light allows detection of body contourBack to article page