Home strengthening exercise for knee osteoarthritis: the MULTI-ONE randomised controlled trial

Active exercise groups Participants will be randomly assigned a physiotherapist (stratified by group allocation - ‘one’ or ‘five’ exercise arm using random permuted block sizes) and research staff will book three consultation appointments (1, 2 and 6 weeks post-randomisation, 30 minutes each) on behalf of the participant. The consultations with the physiotherapist will occur via telehealth (Zoom video- conferencing), for prescription, monitoring and progression of a home strength program that participants will be asked to undertake for 12 weeks, but encouraged to continue beyond that time up until 9 months. Physiotherapists will be permitted to use their clinical judgement to prescribe exercise(s) from a pre-determined list of allowed exercises that reflects the typical home strength exercises prescribed in the literature for knee OA and by physiotherapists in Australia. Physiotherapists will be asked to prescribe the exercise(s) that they think will be most beneficial in relieving pain and improving function for a given participant. Exercises will be selected from a list including quadriceps exercises (including weightbearing such as squats and non-weightbearing exercises such as seated knee extensions), hamstrings exercises (such as hamstring curls or seated knee flexion), hip exercises (such as crab walking or bridges) and calf exercises (such as calf raises). Participants will be asked to perform prescribed exercises at home (3 sets of 12 repetitions for each exercise), three times/week. The only difference across trial arms is in the number of exercises that will be prescribed (one versus five as per the randomisation schedule). The physiotherapist will individualise the technique of each exercise (e.g. depth of knee bend, amount of body weight, hold time, colour of exercise band etc) to encourage the participant to work at an intensity of 5-7 out of ten (hard to very hard) on the modified Borg Rating of Perceived Exertion CR-10 scale for strength training. At subsequent consultations, physiotherapists may replace a prescribed exercise(s) for a different exercise(s) if required (eg because an exercise is too easy, too hard, aggravates the knee etc) as long as they adhere to the allocated number of exercises (ie a participant’s program contains only the allocated number of exercises of either one or five) and choose only from the defined list of exercises. Consultations will occur via the video-conferencing facility of Zoom, a commercial cloud-based system accessible from any internet-connected computer, laptop or mobile device. Physiotherapists will consult from their clinic with participants based at home or wherever is suitable (e.g. work). Physiotherapists will be provided access to a website containing a video library of exercises to allow them to provide real-time demonstration of exercises to participants. This will be shared with the participants via a share-screen feature on Zoom so that the participant is able to view a demonstration of the exercise during the consultations. Participants will not have access to the online video library outside of the consultations. During each consultation, physiotherapists will email participant’s exercise handouts for how to perform each of their prescribed exercises (the research team will provide the physiotherapists with standardised digital instructions for each exercise on the allowed list of exercises to facilitate this). Semi-structured electronic consultation notes will be recorded by the physiotherapist for each consultation and submitted to research staff at the completion of each consultation. Notes will be scrutinised by research staff for physiotherapist fidelity to exercise protocols.