Figure 2. Execution times and standard deviations (shaded area) of a single inverse kinematics operation with respect to the number of inertial measurement units (IMUs).

The execution times are presented as mean over 10 trials for two different musculoskeletal models (lower body and torso model and full-body model) using one, seven, or 12 IMUs. IMU quaternions orientations were retrieved from previously recorded walking trials. Red diagonal cross: lower-body model and laptop computer. Green cross: full-body model and laptop computer. Blue circle: lower-body model and desktop computer. Purple square: full-body model and desktop computer.