Postural Strategies, Muscle Activation, and Perceived Strain in Drilling Tasks: Implications for Digital Human Model Prediction

Abstract

Accurately predicting posture in drilling tasks remains challenging for Digital Human Models (DHMs), as individuals differ in how they balance reach, force transmission, and stabilization. This exploratory study investigated how drilling height affects posture, muscle activation, and perceived strain during static simulated drilling. Eleven participants performed the task at four standardized heights while joint angles, EMG activity, and subjective ratings were recorded. Shoulder elevation showed the clearest height-related changes, while elbow, wrist, and trunk adjustments were smaller and more individually variable. Muscle activation patterns broadly reflected these kinematic trends, and subjective strain increased mainly in extreme postures, with only weak links to EMG. Overall, the combination of stable within-individual behaviour and pronounced between-individual differences indicates that the DHMs should incorporate multiple feasible posture strategies. Given the small sample and static, non-vibrating setup, the findings are preliminary but provide a useful basis for refining posture prediction in drilling tasks.

Keywords: Drilling Tasks, Digital Human Modelling, Posture Prediction, Physical Strain, Design Development

DOI: 10.54941/ahfe1008199