There is global recognition in clinical guidelines and governing bodies that low back pain (LBP) should be managed with a biopsychosocial approach. Despite this, research indicates that physiotherapists, who treat the majority of LBP patients in the community, do not feel confident in using this treatment approach. Previous work to support implementation in this field has resulted in low uptake and has highlighted several barriers to implementation, including the need for additional ongoing support. The use of a local champion to support implementation has been successful in other fields and thus, represents a viable strategy to explore. Before undertaking a fully powered trial to evaluate the effectiveness of a champion for implementation, a pilot study is being conducted to determine the feasibility of the intervention as well as determining the feasibility of using a cluster randomised controlled trial to evaluate it.

In this study, a pragmatic cluster randomised controlled trial design will be used with an embedded qualitative interview study. Physiotherapists will be recruited who manage LBP in any publicly funded physiotherapy departments within Newfoundland and Labrador, Canada. Individual sites will be grouped into clusters based on their number of full-time physiotherapists, geography, and organisational relationships. All participants will be asked to complete a previously developed online training course to upskill them to deliver a biopsychosocial evidence-based intervention for LBP. Clusters randomised to receive a local champion will receive additional support from their champion. A basic champion training package has been developed based on known barriers in the literature. This will be tailored by co-developing aspects with study champions based on a comprehensive assessment of perceived implementation barriers using the Theoretical Domains Framework (TDF) and the Capability, Opportunity, Motivation and Behaviour (COM-B) model. A range of physiotherapist-level outcomes pre-post training will be measured and implementation of the evidence based biopsychosocial intervention will be monitored during a 6-month period after completion of the online training. After this 6-month period, a purposive sample of physiotherapists from each cluster who had both implemented and failed to implement the biopsychosocial intervention will be interviewed.

Inclusion Criteria:

• Any publicly funded physiotherapy department within Newfoundland and Labrador working with adult patients with LBP are eligible to participate.
• Clinical leads need to be able to identify at least one champion at each site should they be allocated to the champion arm. We defined a champion as a physiotherapist in the musculoskeletal outpatient department who i) could commit the additional time for training, ii) would be willing to provide support to their peers at the sites within their cluster and iii) demonstrates enthusiasm about intervention to manager.

Exclusion Criteria:

• Physiotherapy departments who do not treat adult patients with LBP will be excluded.