ERGONOMIC DEVELOPMENT OF A COMPUTER POINTING DEVICE – A DEPARTURE FROM THE CONVENTIONAL PC MOUSE TOWARDS CAD USERS Miguel L. Lourenço, Rui A. Pitarma, Denis A. Coelho
OUTLINE • Computer usage and musculoskeletal pain • Aim • Method • Research Plan • Discussion • References
COMPUTER USAGE AND MUSCULOSKELETAL PAIN • computer usage has been indicated by several research studies to play a role in the development of neck and upper extremity pain, especially hand and forearm musculoskeletal pain associated with intensive mouse use • efforts have been ongoing towards proposing alternative pointing devices, albeit these have persisted in triggering hand and forearm musculoskeletal pain in conjunction with intensive use of the pointing device
COMPUTER USAGE AND MUSCULOSKELETAL PAIN • the recent and rising use of Touch Screens (e.g. tablets) has been subjected to study with results showing that the risk of developing musculoskeletal symptoms remains when they are intensively used for a long period of time • touch-screen tablet users are exposed to extreme wrist postures that are less neutral than those assumed with other computing technologies and may be at greater risk of developing musculoskeletal symptoms
COMPUTER USAGE AND MUSCULOSKELETAL PAIN • Tablet PCs entail antagonist ergonomic parameters (screen and keyboard conflict for optimal positioning) • even when adopting palm rejection technology as it generally reduces discomfort but with increased wrist extension and with no benefit to shoulder unloading
AIM • many studies compare usability of two or more computer pointing devices, Rollermouse, Rollerbar, Traditional mouse, TrackPoint and Track-ball types, Touch pad and Touch screen and Joystick, showing their advantages and disadvantages in relation to each other • but information available in scientific literature relating to the complete process of developing a specific computer pointing device is sparse with respect to ergonomics
AIM • ordinary users of computerized workplaces perform tasks that can switch between using the keyboard and using the pointing device • CAD operators use the computer pointing device in a continuous way • some operators use two devices simultaneously, one for the left hand (knob) and one for the right hand (mouse)
AIM • literature review resulted in need to develop and, or, improve a computer pointing device based on a wide range of information of an ergonomic nature • seeking to improve performance and reduce the risks of musculoskeletal disorders • providing it with useful features for envisaged use by CAD operators
METHOD • first part includes a systematic review of the literature, helping to select the most suitable product to improve • second phase includes the ergonomics-oriented development of a computer pointing device • the traditional PC mouse is selected, objective being its special application in the CAD field where accuracy is required, with handling improved, speedy movements and long periods of use
METHOD • various issues are being studied and considered affecting the movements related to the distal action and proximal action, and to the weight of the devices • mouse weight might influence the wrist motion and the forearm muscle activity when using a PC mouse in a high operation speed, while such effect is diminished in a low operation speed
METHOD • mouse with a proper weight would promote improved movement efficiency and decrease the muscular costs during fast operation • proper mouse weight could hence benefit the users in terms of increasing the movement efficiency (during fast operation in high speed tasks), dimensions and geometry based on anthropometry, hand gestures and comfortable hand postures
RESEARCH PLAN • rough sketching is used to develop conceptual designs, followed by 3-D modelling and the fabrication of mock-ups and functional prototypes • ergonomic evaluation of the prototype is to be performed by physical usability testing of these devices enabling the establishment of some of the design requirements and implementing experimental procedures based on literature
RESEARCH PLAN • approximately twelve undergraduate male and female students (Industrial Design) are to participate in this study • evaluation tasks will include 3D CAD testing (simple exercises) • tests are to be performed after a short adjustment/training time period using the new device and compared to the standard PC mouse model of CAD PC workstations
RESEARCH PLAN • order of use of the different types of PC mouse is to be randomized • usability-wise, it is intended to use task time (e.g. in controlling the rotation of 3D models, i.e. digital solids) complemented with Jakob Nielsen’s thinkaloud protocol and completing interview
DISCUSSION • it is intended with the study to ascertain whether a newly designed device will provide improved physical object usability compared to the conventional handheld PC pointing device • further research tests should include a larger group of participants and measure more objective parameters such as muscle activity by EMG and infrared thermography, movement times recorded by software providing a measure of performance.
REFERENCES • Camilleri, M.J., Malige A., Fujimoto, J. and Rempel D.M. (2013). ”Touch displays: The effects of palm rejection technology on productivity, comfort, biomechanics and positioning”. Ergonomics, 56(12): 1850-62. • Chen, H.M., Lee, C.S., and Cheng, C.H. (2012). “The weight of computer mouse affects the wrist motion and forearm muscle activity during fast operation speed task”. European Journal of Applied Physiology. Vol. 112, Issue 6, pp. 2205-2212. • Conlon C. F., N. Krause, and David M. Rempel (2009). “A Randomized Controlled Trial Evaluating an Alternative Mouse or Forearm Support on Change in Median and Ulnar Nerve Motor Latency at the Wrist”. American Journal of Industrial Medicine 52 (4): 304-310. • Fiorentino, M., Uva, A.E., Fabiano, M.D., and Monno, G. (2010). “Improving bimanual 3D input in CAD modelling by part rotation optimization”. Computer-Aided Design. Advanced and Emerging Virtual and Augmented Reality Technologies in Product Design. Vol. 42, Issue 5, pp. 462-470.
REFERENCES • Kluth, K., and Keller, E. (2014). Rollermouse vs. Standard Computer Mouse – Electromyographic and Subjective Assessment of the Usability in Applications with Graphical user interfaces. Advances in Physical Ergonomics and Human Factors: Part I, 14, 235. • Lai, H.H., and Yang, S.L. (2012). “An Ergonomics-oriented Product Development and Evaluation Process: A Case Study of Children’s Pointing Device” Journal of Convergence Information Technology, Vol. 7 Issue 6, pp.323. • Odell, D. and Johnson, P. (2007). “Evaluation of a mouse designed to improve posture and comfort”. Proceedings of the Working with Computer Systems Conference-International Ergonomics Association, Stockholm, Sweden. • Rempel, D., Camilleri, M.J., and Lee, D.L. (2014). “The design of hand gestures for human-computer interaction: Lessons from sign language interpreters”. International Journal of Human-Computer Studies. Vol. 72, Issues 10-11, pp. 728735.
REFERENCES • Young, J., Trudeau, M., Odell, D., Marinelli, K., and Dennerlein, J. (2013). “Wrist and shoulder posture and muscle activity during touch-screen tablet use: Effects of usage and configuration, tablet type, and interacting hand Work”. Vol.45, Issue 1, pp. 59-71.
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