Figure 4. Execution times and standard deviations (shaded area) of a single inverse kinematics operation with respect to the number of inertial measurement units (IMUs), i.e., number of segments with random orientation data.

The values are calculated over 10,000 IK operations for two different musculoskeletal models, two different computers and one, seven or 12 inertial measurement units (IMUs). Randomly selected unit quaternions were used as IMU orientations. 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.