Timing evaluation of one-handed handling based on muscular activity.

The aim of this study was to evaluate muscular activity during one-handed handling. Twenty right-handed male participants volunteered to take part, and electromyography signals were recorded from 14 upper limb muscles. The independent variables were direction and muscle, and the dependent variables were muscular activity and activated duration. The findings from the study revealed that the upward direction exhibited significantly higher muscular activity compared to other directions. This could be attributed to the prolonged movement time and the need for lifting above the shoulder in the upward direction. The right direction involved abduction and external rotation. It can be inferred that internal rotation had greater strength than external rotation due to the mass of anterior musculature. The external rotation of the glenohumeral joint is considered to have a passive stabilizing effect and promotes scapular stability by preventing interference between the acromion and the greater tubercle of the humerus.