A 1RM Strengthening and Exercise Programme for the Treatment of Knee Osteoarthritis: A Quality-Improvement Study

Background: The Kneefit programme is a 12-week strengthening and exercise programme, personalised using body-weight ratios, for people with knee osteoarthritis. Objectives and Design: This quality-improvement study was conducted to evaluate the effectiveness of the programme for managing symptomatic knee osteoarthritis. Methods: The Kneefit programme was delivered between 20 August 2013 and 7 January 2014 and included six weeks of supervised strengthening, balance, and cardiovascular exercise in a group at the local hospital, followed by six weeks of unsupervised exercise. Leg-press and knee-extension 1RM scores were assessed at baseline, six weeks, and twelve weeks. In addition, patient-reported outcome measures (Oxford Knee Score, EQ5D, Patient Specific Function Score (PSFS)) were assessed. Wilcoxon Signed Rank tests were used to evaluate the changes from week 1 to week 6 and week 12. Results: Thirty-six patients were included at baseline and at six weeks, and 31 patients completed their twelve-week assessment. Statistically significant improvements were found at 6 and 12 weeks for change for the Oxford Knee Score (median change: 4.0, IQR 4.0 to 9.0, p < 0.001 and 4.0, IQR 0 to 8.0, p < 0.001), EQ5D-5L (median change: 0.078, IQR 0.03 to 0.20, p < 0.001 and 0.071, IQR 0.02 to 0.25, p < 0.001) and the PSFS (median change: 1.3 IQR 0 to 2.6, p = 0.005 and 2.3 IQR −0.3 to 3.3, p = 0.016). In addition, significant improvements were found for 1RM leg-press and knee-extension scores on both the affected and unaffected legs. Conclusion: The Kneefit programme was successful at improving both functional and strength-related outcome measures in patients with knee osteoarthritis. Our findings suggest that tailoring strength exercises based on the 1RM strength-training principles is feasible in this population.