Prefabricated contoured foot orthoses to reduce pain and increase physical activity in people with hip osteoarthritis: protocol for a randomised feasibility trial

Introduction The aim of this randomised feasibility trial is to determine the feasibility of conducting an adequately powered randomised controlled trial (RCT) investigating the efficacy of prefabricated contoured foot orthoses in people with hip osteoarthritis (OA). The secondary aims of the trial are to compare the effect of prefabricated contoured foot orthoses to a flat shoe insert comparator on outcomes of hip-related pain, physical activity and quality of life. We hypothesise that the demand, implementation, acceptability and practicality of foot orthoses as a treatment option for people with hip OA will be deemed feasible, informing the development of an adequately powered RCT to evaluate the efficacy and long term outcomes. Methods and analysis We will recruit 28 people with hip OA who will be randomised to receive either prefabricated contoured foot orthoses or flat shoe inserts to use for a 6-week period. Both groups will receive standardised education on hip OA and physical activity. The study's primary outcome is the feasibility domains of demand, implementation, acceptability and practicality. The secondary outcomes include the change in Hip Osteoarthritis Outcome Score-12, Patient Health Questionnaire-9, Brief Fear of Movement Scale for OA, Physical activity accelerometry and the Physical Activity Questionnaire-short form. Descriptive statistics will be used to describe feasibility outcomes with limited efficacy analysis used for the secondary outcomes. Linear mixed models will be used to analyse between-group differences at 6 weeks, with baseline values used as covariates, treatment allocation as a fixed factor and participant as a random factor. Ethics and dissemination This trial has been approved by the La Trobe University Human Research Ethics Committee (HEC20427), St. Vincent's Hospital Melbourne, Human Research Ethics Committee (HREC 266/20) and Northern Health Research Governance (NH-2021-292862). The results will be disseminated via a peer-reviewed journal and presented at international conferences. Trial registration number NCT05138380