The Moderating Effect of the Severity of Baseline Musculoskeletal Discomfort on the Effect of an Alternative Keyboard: A 5-Month Randomized Clinical Trial

Abstract

Objective: To determine if baseline discomfort severity would moderate differences in 5-month follow-up discomfort in those using a fixed split-angle (FSA) keyboard compared to those using a standard (ST) keyboard. Procedure: Computer operators with keyboard related musculoskeletal discomfort were randomly assigned to use an FSA keyboard or a ST keyboard in their workplace for 5 months. They reported weekly levels of discomfort using the Weekly Discomfort Survey. Result: The interaction between baseline severity and keyboard was significant. This significant interaction suggests that those who had moderate/severe baseline discomfort who used the FSA keyboard improved significantly more than: 1) those who had moderate/severe baseline discomfort who used the ST keyboard; or 2) those who had none/mild baseline discomfort and used either keyboard.