The Impact of Prolonged Standing on Musculoskeletal Pain

This is a cross-sectional and prospective cohort study using a biopsychosocial approach to investigate office workers at risk of standing-induced musculoskeletal pain. The purpose of this study is to determine which factors are associated with developing or worsening of musculoskeletal pain (changes in the Visual Analogue Scale from baseline) during a 60 minute standing paradigm.

Background/rationale

There is growing national and international evidence for the negative health impact of sedentary behaviour at work. A strategy being increasingly adopted to reduce prolonged sitting is to spend some of the work day in standing. However, for some adults, prolonged standing is associated with the development of musculoskeletal pain. We are investigating which factors are associated with developing of musculoskeletal pain during standing when using a height-adjustable desk. Previous studies have used an induced-pain paradigm to understand risk factors for developing musculoskeletal pain during a prolonged standing task that simulates the work environment (standing paradigm). Identifying those office workers who are at risk of developing musculoskeletal pain during standing will provide information to guide health professionals and individuals in making decisions about optimal workstation design.

Objectives and hypothesis

* Cross-sectional study: Identify which factors are associated (demographic, physical, psychological and work-related factors) with standing-induced musculoskeletal pain in office workers during a standing paradigm.
* Prospective cohort study: Identify incidence/prevalence and risk factors of low back pain, and disability associated with low back pain in office workers in a 1-year prospective cohort.

Methods

* Setting, locations and relevant dates: testing is conducted in the University of Queensland (Brisbane, Australia). Data collection commenced in May of 2018 until 30th of April of 2019 (cross-sectional study); and follow-up is from June of 2018 until 30th of April of 2020 (prospective cohort study).
* Participants: recruitment is through posting flyers on campus of The University of Queensland; through the weekly electronic university staff newsletter at this University; and through Facebook announcements. Interested participants were directed to an online questionnaire (hosted by Survey Monkey) to determine eligibility. Participants meeting the eligibility criteria were contacted via email to schedule an appointment.
* Variables: see "outcomes measures".
* Study size: a convenience sample of 40 office workers will be recruited. Based on previous studies that have compared developers and non-developers of standing-induced low back pain, this sample size was considered sufficient to detect a significant difference in some of the physical outcome measures such as lumbar lordosis (Sorensen et al. 2015a); trunk muscle activation (Ringheim et al. 2015) and active hip abduction (Nelson-Wong et al. 2008).
* Statistical analysis: subjects will be separated into Pain Developers (PDs) and Non-Pain Developers (NPDs). A Chi-square analysis or a Fisher's Exact test will be conducted to test for differences in the distribution of qualitative and proportional variables in PDs and NPDs. Independent groups t-tests, will be conducted to test for differences in quantitative variables between PDs and NPDs. A Pearson correlation coefficient and one-way analysis of variance test will be conducted to test for differences for average Visual Analogue Score (VAS). A simple linear regression analysis will be performed to examine the degree to which biopsychosocial variables predict PDs. Statistical analyses will be performed in SPSS version 24 (IBM, Armonk, NY).Statistical significance for all tests will be set at p ≤ 0.05.

Eligibility Criteria:
Inclusion Criteria:

* Office-based workers who perform more than 30 hours per week mostly sitting at a computer,
* With aged 18 or above.

Exclusion Criteria:

* not office-based workers,
* pregnant or less than six months postpartum,
* had experienced any major trauma or had surgery to the spine or lower limb over the last 12 months,
* had been diagnosed with any neurological or systematic pathology (such as rheumatoid arthritis, multiple sclerosis or ankyloses spondylitis).