A pilot, feasibility randomised, controlled trial comparing walking exercise against pendulum leg swinging exercise in adults with osteoarthritis of the knee.

Abstract Background.In China, swinging the leg backwards and forwards is a commonly used therapy for people with osteoarthritis of the knee. One rationale is that movement without weightbearing may increase the range of movement by allowing a greater range of pian-free movement at the knee. There have been no studies evaluating its effectiveness. Before undertaking a large trial, a pilot study is needed to establish feasibility and an estimate of the sample size needed.Methods.This will be a parallel-group, assessor-masked, randomised, controlled study comparing the effect of pendulum leg swinging against an equivalent time of walking exercise. Patients will be recruited from the outpatient and inpatient orthopaedic surgery services in a large, class III general hospital in Wuhan, China. To be selected they must have clinically diagnosed osteoarthritis of the knee. Patients will be excluded if they have additional knee disease, have had hip or knee arthroplasty or a tibial osteotomy, are taking steroids or have done so in the preceding three months, have another illness affecting mobility or participation in the study, are pregnant, or have a body mass index (BMI) over 36. They will be allocated randomly using sealed, prefilled envelopes on a 1:1 basis. Data will be collected by masked observers at baseline and 12 weeks. Measures include the Oxford Knee Score, the six-minute walking distance, pain measured on a numerical rating scale, the 30 second sit-to-stand test, quadriceps muscle strength, and accelerometer data. Feasibility data will record data-completion rates, recruitment and retention rates, adherence with treatment, and patient experience including adverse events. The two interventions will involve a gradual increase of exercise between baseline and 6 weeks with a further six weeks at the level set for each patient. Data analysis will be descriptive, with comparative analysis on outcome measures to give an estimate of sample size needed in a full trial.Discussion.Swinging the leg like a pendulum combines exercise and movement of the knee without bearing weight. Exercise is known to give some benefit but it is not known whether joint movement without weight-baring has any beneficial effect. A large trial would be needed. This trial will establish how feasible it might be to undertake a large trial.Trial registration details.Registry: Chinese Clinical Trial RegistryNumber: ChiCTR2100051275Date: 17th September 2021URL: https://www.chictr.org.cn/historyversionpuben.aspx?regno=ChiCTR2100051275