Introduction: Knee osteoarthritis (KOA) is a prevalent degenerative joint disorder, often accompanied by comorbidities like type 2 diabetes mellitus (T2DM). These conditions have a significant impact on patients' sleep quality and metabolic health. Current treatments for KOA primarily focus on symptom management, while innovative approaches targeting interconnected health outcomes remain underexplored. The lumbar knee recovery device, a non-invasive device patented in Iran, offers potential benefits by enhancing lumbar-knee synchronisation, improving blood circulation and optimising cellular metabolism. This randomised controlled trial (RCT) aims to evaluate the device's effectiveness in improving sleep quality and regulating blood glucose levels in diabetic patients with KOA.

Methods and analysis: This RCT aims to evaluate the impact of using the lumbar knee recovery device (Kamarasa) on sleep quality, blood glucose levels, HbA1c (blood glucose control level over the past 90 days) and body mass index (BMI) in patients with T2DM and grade 1-3 KOA. The study will be conducted at the Orthopedic Clinic of Imam Khomeini Hospital, Tehran, and the Health and Wellness Clinic. Eligible participants will be randomly allocated into two groups: the intervention group (receiving 10 supervised sessions using the Recovery device over 3 months) and the control group (receiving standard KOA and diabetes care). A total of 37 participants will be included in each group. The primary outcome, sleep quality, will be assessed using the Pittsburgh Sleep Quality Index at baseline and 3 months post intervention. Secondary outcomes will include random blood glucose levels, which will be measured at 10 intervals during the study; BMI, measured at the start and end of the study and HbA1c, assessed at both baseline and post intervention. The Western Ontario and McMaster Universities Arthritis Index will be used to assess pain, stiffness and physical function, also at both baseline and 3 months. Appropriate statistical tests, including two-sample t-tests, χ² tests, analysis of covariance or linear regression, will be performed based on the type of variables using SPSS V.23. Additionally, standardised intervention effect sizes will be calculated for each outcome.

Ethics and dissemination: Ethical approval for this study was obtained from the Research Ethics Committee of the School of Nursing and Midwifery at Tehran University of Medical Sciences with reference number (IR.TUMS.FNM.REC.1403.145). Additionally, the study protocol was registered with the IRCT under the identifier IRCT20191027045257N7 on 24 November 2024.

Trial registration number: Iranian Registry of Clinical Trials (IRCT20191027045257N7). This clinical trial was registered on 24 November 2024.