The association between rheumatoid arthritis related structural changes in hands and computer keyboard operation.

INTRODUCTION: This cross-sectional study examined the effect of structural changes caused by rheumatoid arthritis (RA) on computer keyboarding style to provide insights on how changes may affect worker performance.
METHOD: Computer keyboarding styles, as measured by the keyboard-personal computer style instrument, were compared between 45 keyboard operators with RA and 29 without. A severity of structural changes score (SSCS) was assigned after recruitment by observing subjects' hands while operating a keyboard. Significant differences between each item of keyboarding style by diagnosis were identified through Chi square analyses. Logistic regression models with age, diagnosis, SSCS, and touch typing training as the predicators further evaluated the effect of structural changes on each item of personal keyboarding style.
RESULTS: Significantly more keyboard operators with RA used high force keystrokes, did not use a wrist rest, moved their hands to strike keys, maintained their wrists and fingers in a fixed position and used fewer than two fingers to activate keys. The amount of variance explained by each model varied from 8 to 56%. SSCS was the most common predictor of keyboarding style (54% of significant models), followed by age (35% of significant models), diagnosis (19% of significant models), and touch typing training (15% of significant models).
CONCLUSION: Severity of structural changes and age are significant predictors of keyboarding style for computer operators with RA. The keyboarding styles used by computer operators with RA appear to reduce typing productivity and have the potential to put stress on joints already affected by RA. Computer operators with RA may benefit from worksite modifications that address keyboarding style such as alternate keyboards.