Left-handed versus right-handed computer mouse use: effect on upper-extremity posture
Introduction
During the last decade, computer use has greatly increased both at home and at work. Moreover, graphic interfaces have become the standard, so the use of input devices, such as the computer mouse, have increased tremendously. Although the forces involved in manipulating input devices are usually small, postures adopted might put the users at risk of developing musculoskeletal disorders. Few studies have reported a possible association between frequent computer mouse use and neck-shoulder pain or pain in other regions of the upper-extremity (Aaras et al., 1998; Fernstrom and Ericson, 1997; Hagberg, 1995; Jensen et al. (1998), Jensen et al. (2002). Computer mouse use has been reported to involve shoulder flexion, abduction and external rotation (Karlqvist et al., 1994). It has also been shown that the use of a keyboard with a numeric keypad influences the mouse position by increasing the distance of the mouse with the sagittal plane of the body, therefore, requiring larger shoulder abduction, and increasing muscular load (Cook and Kothiyal, 1998; Karlqvist et al., 1998). Computer-work also involves the adoption of static postures for long periods of time. Even before the extensive use of the computer mouse, a relationship between weak static muscular contractions and musculoskeletal disorders has been proposed (Maeda, 1977; Westgaard et al., 1986). Shoulder flexion and abduction have also been identified as risk factors for neck and shoulder musculoskeletal disorders (Hagberg, 1981; Kilbom and Persson, 1987; Schuldt et al., 1987). The reduction of shoulder flexion and abduction during mouse work could help reduce the risk of developing musculoskeletal disorders in the shoulder region. Cook and Kothiyal (1998) proposed that the use of the mouse with the left hand could be an alternative for reducing shoulder posture constraints because the distance of the mouse hand to the midline of the body would be reduced.
With this strategy in mind, a large company in Canada implemented ergonomics training for their office employees, with one of its recommendations being the use of the mouse with the left hand. The idea behind this recommendation was to eliminate hand travel over the numeric keypad, thereby reducing the extent of motion when going from the mouse to the keyboard. Postural constraints on the shoulder, related to mouse use, would therefore be reduced.
The purpose of this study was to evaluate the advantages and disadvantages related to different mouse-use methods on postural constraints and performance, before and after an office ergonomics awareness training session (a 2-h small-group presentation on how to adjust an office workstation “ergonomically”, appropriate stretching exercises, and the rationale for recommending the use of the mouse with the left hand).
The main hypothesis of the study is that the use of the mouse with the left hand is an alternative for reducing postural constraints of the whole upper-extremity when using standard keyboard with a numeric keypad.
Section snippets
Subjects
Thirty-one office workers, who had not yet received the ergonomics training, volunteered to participate on the first session of measurements (baseline). Of these, 29 returned 1 month later (after the office ergonomics training) for the second session of measurements. Data from two subjects were lost because of technical problems, therefore the data of 27 subjects were used. There were 24 women (mean age: 42 yrs, range: 33–51 yrs; mean weight: 69 kg, range: 48–113 kg; mean height: 161 cm, range:
Results
The use of the mouse with the right hand and right mouse button (RR condition) did not result in any significant changes of posture or perception as compared to the left mouse button use (RL condition). Moreover there were no significant differences on any angles between the trials. Therefore the remainder of this section will focus on the comparison of the right hand, left button mouse use (RL condition) and the left hand, left button mouse use (LL condition). The results presented will be the
Methodological considerations
This study aimed at documenting the advantages and disadvantages of different techniques for using the computer mouse, relying essentially on a postural analysis of the upper-extremity on the side of the mouse. It is important to recognize that it is impossible from this study to establish if the reduction in postural constraints, as observed here, is sufficient to reduce the risk of developing or aggravating musculoskeletal disorders. A longitudinal evaluation could help document this aspect.
Conclusion
This study shows that use of the mouse on the left side as compared to the right side of a standard keyboard, reduces the postural constraints of the upper-extremity using the mouse. For work involving both keyboard and mouse use, and without extensive use of the numeric keys, it would probably be preferable to use a keyboard without the numeric keypad if the mouse is to be used on the right-hand side. If such keyboards are unavailable, use of the mouse on the left side is an interesting
Acknowledgements
This study was funded by the IRSST. The authors would like to thank Lucie Blais, Angiolina Mercuri, Christian Larue, and Pierre Desjardins for their support.
References (19)
- et al.
Musculoskeletal, visual and psychosocial stress in VDU operators before and after multidisciplinary ergonomic interventions
Appl. Ergon.
(1998) - et al.
Influence of mouse position on muscular activity in the neck, shoulder and arm in computer users
Appl. Ergon.
(1998) - et al.
Computer mouse or trackpoint—effects on muscular load and operator experience
Appl. Ergon.
(1997) - et al.
Musculoskeletal symptoms and duration of computer and mouse use
Int. J. Ind. Ergon.
(2002) - et al.
Influence of sitting posture on neck and shoulder EMG during arm-hand work movements
Clin. Biomech.
(1987) Psychophysical bases of perceived exertion
Med. Sci. Sports Exercise
(1982)- et al.
A joint coordinate system for the clinical description of three-dimensional motionsapplication to the knee
J. Biomech. Eng.
(1983) Work load and fatigue in repetitive arm elevations
Ergonomics
(1981)The ‘Mouse-Arm Syndrome’—Concurrence of musculoskeletal symptoms and possible pathogenesis among VDU operators
Cited by (17)
Observed finger behaviour during computer mouse use
2008, Applied ErgonomicsCitation Excerpt :In the same study, intensive mouse usage was found to be a major risk factor for forearm pain, as well as intensive keyboard usage, however, to a smaller degree (Kryger et al., 2003). While the exact mechanism behind the forearm and hand/wrist pain associated with computer mouse use still remains unclear, a leading hypothesis is that mouse users are exposed to prolonged, static working postures involving hand and wrist extension (Burgess-Limerick et al., 1999; Delisle et al., 2004; Jensen et al., 1998). During keyboarding, maintaining wrist and elbow postures for extended periods during typing creates static loading in the wrist extensors (Keir and Wells, 2002).
Nondominant hand computer mouse training and the bilateral transfer effect to the dominant hand
2021, Scientific ReportsEvaluating the match/mismatch between the mouse dimensions and the hand anthropometry of the primary school students
2019, IOP Conference Series: Materials Science and EngineeringEffects of work surface and task difficulty on neck–shoulder posture and trapezius activity during a simulated mouse task
2019, International Journal of Occupational Safety and ErgonomicsPhysical risk factors and observational tools for computer office workers–an overview
2018, International Journal of Mechanical Engineering and TechnologyIndividual and work-related risk factors for musculoskeletal pain among computer workers in Nigeria
2018, Archives of Environmental and Occupational Health