Background: Knee osteoarthritis (OA) is a highly prevalent degenerative joint disease with a significant global healthcare burden. Over 70% of the population experiences symptomatic knee OA. Purpose: This study compared the efficacy of adding retro-walking (RW) or whole-body vibration (WBV) on knee functional disability in individuals with chronic grade III knee OA. Methods: A randomized controlled trial enrolled 45 participants diagnosed  with chronic grade III knee OA, aged 40-55 years. Participants were randomly assigned into three groups (n=15/group): Group A: Routine physiotherapy  program (straight leg raise, isometric quadriceps, isometric hip adduction,  terminal knee extension, semi-squat, and leg press). Group B: Routine physiotherapy program, in addition to the RW program. Group C: Routine  physiotherapy program and WBV training. Knee functional disability was assessed using the Arabic version of the Western Ontario and McMaster Universities Osteoarthritis Index (ArWOMAC) at baseline and after six weeks. Results: All groups showed significant improvements in knee function (pain, stiffness, physical function) (p < 0.05) after six weeks compared to baseline. However, no statistically significant differences (p > 0.05) were noticed between the groups in any subscales or the total ArWOMAC scores post-treatment. Conclusion: Adding RW or WBV to the routine physiotherapy program produces a similar improvement in knee function as the routine physiotherapy program. So, when routine physiotherapy is used, either adding RW or WBV will not produce better results for improving knee function in individuals with chronic grade III knee OA.