Figure 4From: A portable system for collecting anatomical joint angles during stair ascent: a comparison with an optical tracking deviceMean angles and standard deviation of the right leg in the sagittal plane. Thick red dotted lines are the mean angles obtained by IMUs and the thick blue solid lines are those obtained by the optical tracking device. Thin lines represent the standard deviations. A: Ankle, B: Knee, C: Thigh.Back to article page