title: Evaluation of flat, angled, and vertical computer mice and their effects on wrist posture, pointing performance, and preference.
abstract: BACKGROUND
  Modern computer users use the mouse almost three times as much as the keyboard. As exposure rates are high, improving upper extremity posture while using a computer mouse is desirable due to the fact that posture is one risk factor for injury. Previous studies have found posture benefits associated with using alternative mouse designs, but at the cost of performance and preference.
  
  
  OBJECTIVE
  To develop new computer mouse shapes, evaluate them versus benchmarks, and determine whether there are differences in wrist posture, pointing performance, and subjective measures.
  
  
  METHODS
  Three concept mice were designed and evaluated relative to two existing benchmark models: a traditional flat mouse, and an alternative upright mouse. Using a repeated measures design, twelve subjects performed a standardized point-and-click task with each mouse. Pointing performance and wrist posture was measured, along with perceived fatigue ratings and subjective preferences pre and post use.
  
  
  RESULTS
  All of the concept mice were shown to reduce forearm pronation relative to the traditional flat mouse. There were no differences in pointing performance between the traditional flat mouse and the concept mice. In contrast, the fully vertical mouse reduced pronation but had the poorest pointing performance. Perceived fatigue and subjective preferences were consistently better for one concept mouse.
  
  
  CONCLUSIONS
  Increasing mouse height and angling the mouse topcase can improve wrist posture without negatively affecting performance.
authors.affiliation: Synaptics, Inc., San Jose, CA, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Odell
authors.affiliation: School of Public Health, University of Washington, Seattle, WA, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Johnson
mesh_terms: D000328:Adult; D016287:Computer Peripherals; D003258:Consumer Behavior; D004867:Equipment Design; D006804:Ergonomics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D011403:Pronation; D013647:Task Performance and Analysis; D014953:Wrist / Q000502:physiology*; D055815:Young Adult
keywords: Human-computer interaction; design; ergonomics