Effect of Keyboard Keyswitch Design on Hand Pain

Abstract

This randomized clinical trial evaluated the effects of keyboard keyswitch design on computer users with hand paresthesias. Twenty computer users were matched and randomly assigned to keyboard A (n = 10) or B (n = 10). The keyboards were of conventional layout and differed in keyswitch design. Various outcome measures were assessed during the 12 weeks of use. Subjects assigned keyboard A experienced a decrease in hand pain between weeks 6 and 12 when compared with keyboard B subjects (P = 0.05) and demonstrated an improvement in the Phalen test time (right hand, P = 0.006; left hand, P = 0.06). Keyboard assignment had no significant effect on change in hand function or median nerve latency. We conclude that use of keyboard A for 12 weeks led to a reduction in hand pain and an improved physical examination finding when compared with keyboard B. There was no corresponding improvement in hand function or median nerve latency.

Effects of ergonomic intervention in work with video display units

“…A limited number of well-designed intervention studies with reference groups has been published to evaluate the effectiveness of ergonomic intervention in the office environment (4,(6)(7)(8). There is some evidence that keyboard and mouse users may experience a reduction in upper-extremity and neck pain when using certain alternative keyboards or types of mouse than when using conventional ones (9)(10)(11). A training program in ergonomics (12), workstation adjustment (5,(13)(14)(15), and frequent breaks in VDU work (16) have been shown to decrease the prevalence of musculoskeletal disorders and discomfort.…”

Conservative treatment for repetitive strain injury

“…Applying a cut-off point of ≥ 50% positive items resulted in only five high-quality trials (15,17,18,28,29). Requests to comment on the quality score attributed to the study and to provide more information were sent to all the authors but one, whose recent address could not be traced.…”

“…Requests to comment on the quality score attributed to the study and to provide more information were sent to all the authors but one, whose recent address could not be traced. Only 5 out of 14 authors responded (15,(17)(18)(19)28). As a result of their comments and information, we decided to change the assessments of 18 items on the criteria list as follows: 9 from unclear to positive, 5 from unclear to negative, 1 from negative to unclear, and 3 from negative to positive.…”

“…The outcomes were subjective symptoms [eg, levels of pain (VAS, Pain Beliefs Questionnaire, West Haven-Yale Multidimensional Pain Inventory), numbness or stiffness], and activities of daily living (eg, functional status of the hand, return to work, and interference of symptoms with daily living). Other outcome measures reported in the studies were strength (14,15,17,27), tender points (15,17,18,19), sensibility (27)(28)(29), and depression, anxiety, coping strategies or personal harmony (16,19,(21)(22)(23)(24), but they were all considered to be secondary outcomes.…”

“…In summary, a total of 15 identified trials (12 randomized controlled trials and 3 controlled clinical trials) on conservative treatment for repetitive strain injury met the criteria for inclusion in this review. These studies evaluated the efficacy of physiotherapy (14)(15)(16)(17), exercise (18,19), behavioral therapies (20)(21)(22)(23)(24), chiropractic treatment (25), a multidisciplinary rehabilitation program (26), an energized splint (27), and an ergonomic approach (28,29).…”