title: Biomechanics and performance when using a standard and a vertical computer mouse.
abstract: OBJECTIVE
  to compare the biomechanics and performance while using a vertical computer mouse (VM) and a standard mouse (SM).
  
  
  METHODS
  muscle activation (electromyography), forearm movements (electrogoniometers), performance (Fitts' Law test) and satisfaction (questionnaire) of 16 subjects were evaluated.
  
  
  RESULTS
  there were significant differences between the VM and the SM, respectively, on motion (28° vs. 42° pronation, p = 0.001; 5° ulnar vs. 7° radial deviation, p = 0.016) and muscle activity (13% vs. 16% of extensor carpi activity, p = 0.006; 10% vs. 13% extensor digitorum activity, p = 0.001). VM user satisfaction was good (68); however, time to target was longer (4.2 vs. 3.4 s, p < 0.001).
  
  
  CONCLUSIONS
  using the VM decreased wrist pronation and lowered wrist extensor muscle activity, but additional training and familiarisation time may be required to improve user performance.
  Using a vertical mouse can decrease the exposure to biomechanical risk factors for computer mouse use-related musculoskeletal disorders. Using a vertical computer mouse resulted in less wrist pronation and lower wrist extensor muscle activity. But, training and familiarisation are required.
authors.affiliation: a Department of Physical Therapy , University of Franca , Franca , Brazil.
authors.forename: Paulo R V
authors.initials: PR
authors.lastname: Quemelo
authors.forename: Edgar Ramos
authors.initials: ER
authors.lastname: Vieira
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D016287:Computer Peripherals; D003258:Consumer Behavior; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D005542:Forearm / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D011403:Pronation / Q000502:physiology; D013647:Task Performance and Analysis; D055815:Young Adult