Estimation of Individual Muscular Forces of the Lower Limb during Walking Using a Wearable Sensor System

Figure 2

Procedures for converting the Euler angles from the IMUs to the knee joint angle: (a) extracting the rotation matrices from each IMU, (b) calculating the directional vector of each segment, (c) transforming the reference coordinate from the earth to the trunk, and (d) projecting the vectors into the sagittal plane and calculating the joint angle.