Changes in Desk-Based Workers’ Sitting, Standing and Stepping Time: Short- and Longer-Term Impacts on Musculoskeletal Pain

Sitting at work can be associated with musculoskeletal pain, but the impact of reductions in sitting is not well-understood. We examined relationships with musculoskeletal pain of changes in sitting, standing, stepping, and short and long bouts of these behaviours.Analyses pooled data from 224 desk workers (68.4% women; mean ± SD age 45.5 ± 9.4 years; BMI 28.1 ± 6.1) in intervention trial. Device-assessed (activPAL3) sitting, standing, and stepping time and multisite musculoskeletal pain (Nordic Questionnaire; 12 body areas) were assessed at baseline, three and 12 months. Compositional data analyses in linear mixed-effects regressions examined relationships within 16-waking-hours of the behaviours and their short- and long-bouts, with changes from baseline in acute and chronic multisite musculoskeletal pain at three and 12 months. Analyses were adjusted for initial group randomisation and relevant covariates.At three months, increased standing relative to changes in other compositions was significantly associated with increased multisite musculoskeletal pain [Acute: β = 1.54, 95%CI (0.10 to 2.98); Chronic: β = 1.49, 95%CI (0.12 to 2.83)]. In contrast, increased stepping relative to changes in other compositions was significantly associated with reduced multisite musculoskeletal pain [Acute: β = -1.49, 95%CI (-2.97 to -0.02); Chronic: β = -1.87, 95%CI (-3.75 to -0.01)]. Neither sitting reduction relative to changes in other compositions, nor changes in short- relative to long-bouts of the behaviours, were significantly associated with multisite musculoskeletal pain changes. At 12 months, there were no significant associations for any of the compositional changes.In the short term, while increasing standing with reduced sitting time can be unfavourable, concurrently increasing stepping could potentially reduce musculoskeletal pain. In the longer term, musculoskeletal pain may not be increased by moderate reductions in sitting time through spending more time standing or stepping.