Research Progress in the Bilateral Asymmetry of Hand Force Production in Dynamic Physically-Coupled Tasks was Reported by IEEE JBHI

Our Ph.D. student Chenyang Sun proposed a study about bilateral asymmetry of hand force production in dynamic physically-coupled tasks in IEEE Journal of Biomedical and Health Informatics (IF = 5.772).

Apart from the intrinsic interest for a basic understanding of the mechanism of bilateral force control tasks, the results are also of guiding significance for formulating evaluation criteria of patients’ upper limb coordination training.

Physically-coupled bimanual tasks (activities where a force effect occurs between two human limbs) involve the coordination and cooperation of bilateral arms. Such uncertain contribution of two arms is often studied under static configuration, which is not sufficient to typify all activities of daily life (ADLs). This study aims to investigate people’s bilateral force production and control in dynamic tasks.

Experiments were conducted with a customized robotic system that is characterized with two handles and programmable force fields between them. Fourteen healthy right-handed human volunteers were instructed to generate force with each hand when performing predefined trajectory tracking tasks, in which the sum of forces contributed by the left and the right hand is required to equal a target force.

Significant asymmetry was found in the force output between bilateral hands. With the homologous muscles activated synchronously, the contribution of the left hand was larger, while when the non-homogenous muscles were activated synchronously, the laterality was subject to the moving direction. In addition, when considering the force difference between two hands in terms of direction and magnitude, the former decreased with the increase of the target force, but the latter was more sensitive to moving directions. The results reveal the unique characteristics of non-isometric force control tasks compared with isometric ones.

Chenyang Sun, a Ph.D. student of Southern University of Science and Technology, is the first author of this article. Mingming Zhang, assistant professor of Southern University of Science and Technology, is the corresponding author of this article. Southern University of Science and Technology is the first unit and communication unit.