Stair-Climbing Training with Interferential Electrotherapy Improves Knee Muscle Strength, Dynamic Postural Stability, Pain Score, and Physical Activity in Patients with Knee Osteoarthritis

<b>Background/Objective:</b> This study aimed to compare the functional outcomes, such as knee muscle strength, dynamic postural stability, pain scores, and physical activity, in patients with knee osteoarthritis (OA) on stair climbing training with and without interferential electrotherapy (IFE) for 12 weeks. <b>Methods:</b> A total of 40 knee OA patients with Kellgren-Lawrence (K-L) grade ≤ 2 were enrolled (20 stair-climbing training with IFE vs. 20 stair-climbing training without IFE). The knee quadriceps and hamstring muscle strengths were measured using an isokinetic device. The dynamic postural stability was assessed using postural stabilometry. The pain score was evaluated using the visual analog scale (VAS). Physical activity was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). <b>Results:</b> The WOMAC score was significantly different (<i>p <</i> 0.019) between stair-climbing training with and without IFE in patients with knee OA, while knee muscle strength, dynamic postural stability, or pain score were not (all <i>p ></i> 0.05). <b>Conclusion:</b> Stair-climbing training with IFE was more beneficial for physical activity recovery than stair-climbing training without IFE. Therefore, clinicians and therapists should be aware that stair climbing, which can be practiced in daily life for the management of patients with knee OA, and the addition of IFE may improve physical activity.