Exploring the role of task constraints on motor variability and assessing consistency in individual responses during repetitive lifting using linear variability of kinematics

Exploring Optimal Objective Function Weightings to Predict Lifting Postures Under Unfatigued and Fatigued States

“…To address this concern during lifting, we used Santos Pro to predict origin and destination floor-to-shoulder height lifting postures for ten unique avatars. Each avatar was anthropometrically scaled (height and weight) to create a digital twin for each participant that had completed a 60-minute repetitive floor-to-shoulder height lifting protocol ( Oomen et al, 2022 ). Origin and destination postures were predicted for each avatar 1,331 times, where the objective function settings were varied on each iteration to change the weighting allocated to each of three objective functions.…”

“…To contextualize the predictions to the experimental data ( Oomen et al, 2022 ), we used three external constraints. First, we used end effector and marker target pairings within the software to enforce the hand position (defined using end effectors on the second and fifth metacarpals of each hand) of each digital twin to be in a position within the virtual environment software that was equivalent to the actual hand position of the participant within the lab coordinate system.…”

“…Previously measured motion capture data were obtained from ten participants (six female and four male) recruited from a university population who were completing a 60-minute repetitive lifting protocol for the purpose of evaluating movement variability and fatigue ( Oomen et al, 2022 ). Complete details of the study protocol are reported by Oomen et al, (2022) . Here, we only summarize salient details specific to our modelling efforts.…”