Effects of a sit-stand ergonomic intervention on musculoskeletal discomfort in sedentary office workers : a single case design

Background: Sit-stand workstations have been identified as a strategy to reduce sedentary behaviours in the workplace and may mitigate musculoskeletal symptoms by allowing positional change between sitting and standing. Aim: The aim was to investigate the effect of a sit-stand workstation on standing time in the workplace. Changes in standing time were examined to determine the responsiveness of musculoskeletal symptoms to increased standing in sedentary office workers. Design: Two phase single-case series design Methods: Participants were measured throughout baseline and intervention phases, with the introduction of standing during the intervention phase. Sitting and standing time was objectively monitored through use of a personal inclinometer, in addition to self-reported measures of musculoskeletal discomfort by location, frequency and severity, matched to participant symptoms. Results: Six symptomatic participants (male n=3, female n= 3, age range 25 to 38 years) employed full-time in sedentary occupations were recruited. A reduction in sitting time was observed for three participants, ranging from 15 min/day to 78 min/day. Sitting time was almost exclusively replaced with standing. Musculoskeletal symptoms improved in Troublesomeness and frequency of episodes with at least one area of discomfort reverting to no symptoms for each participant during the intervention phase. However, in general, changes to musculoskeletal symptoms did not exceed the smallest worthwhile change. Conclusion: Changes in objectively measured sitting and standing time were small; therefore, results of reduced discomfort during the intervention phase should be interpreted cautiously. Further research is necessary to examine the potential for reduced sedentary behaviours to influence symptoms of musculoskeletal discomfort in the workplace.