title: Power grip force is modulated in repeated elbow movement.
abstract: The objective of this study was to quantitatively investigate the modulation of power grip force under repeated elbow movement and its relation to muscle cocontraction and potential risk of developing cumulative trauma disorders (CTD). Thirteen right-handed participants without any neuromuscular disorders were recruited. Participants were instructed to hold a digital dynamometer in the hand with three levels of grip forces (20%, 40% and 60% of the maximum grip force) and perform repeated arm movement in the sagittal plane at three speeds (slow, self-paced and fast) with the upper arm voluntarily held by side by the participant. With the increase of motion rate and target force level, the grip force fluctuation, finger flexor muscle activities, elbow muscles cocontraction and apparent stiffness were significantly increased (p < 0.01). This study suggests that the power grip coupled with fast arm movement be avoided as much as possible in the workplace.
  Power grip is usually accompanied with arm movement in workplaces and the increased physical demand might result in higher muscle activities and potentially higher risk of repetitive musculoskeletal injuries.
authors.affiliation: Department of Health Care Sciences, School of Health Professions, UT Southwestern Medical Center at Dallas, 6011 Harry Hines Boulevard, Dallas, TX, USA. fan.gao@utsouthwestern.edu
authors.forename: Fan
authors.initials: F
authors.lastname: Gao
mesh_terms: D000328:Adult; D004550:Elbow / Q000502:physiology*; D004576:Electromyography; D005260:Female; D005583:Fourier Analysis; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D013647:Task Performance and Analysis; D017132:Workplace; D055815:Young Adult