Dual-task interference in a grip and lift task

Abstract

Background & Aims: The aim of this study was to investigate dual-task interference on maximum grip force while performing a grip and lift task. Moreover, the influence of handedness on maximum grip force, and the relationship between maximum grip force and subjective difficulty were also investigated. Methods: Eleven subjects took part in the study. The study experiment was comprised of one single task and three dual tasks: 1 ) grip and lift task, 2 ) grip and lift task with single-leg stance, 3 ) grip and lift task with eyes closed, and 4 ) grip and lift task with calculation. The experiment was conducted in both hands separately. Maximum grip force of four fingers (dominant/non-dominant × thumb/index finger) was compared among tasks and between hands. Results: We found that maximum grip force was increased mainly by the cognitive dual task in both hands, and that there was no difference between hands in the same task. There was a positive correlation between the perceived difficulty and maximum grip force in the dominant hand. Conclusion: Our results suggest that maximum grip force could serve as an objective index for evaluating dual-task interference in upper extremity function.