Sustainability of whole-body electromyostimulation in knee osteoarthritis – 6-month post-intervention follow-up of the randomized controlled EMSOAT study

<title>Abstract</title> <p>Exercise is recommended by all major treatment guidelines of knee osteoarthritis (OA). However, most patients do not maintain the exercise program after cessation of the supervised training period. This study evaluated the sustainability of the positive treatment effects of a 7-month whole-body electromyostimulation (WB-EMS) intervention in overweight individuals with symptomatic knee OA. Seventy-two participants were randomly assigned to a WB-EMS group (n = 36) or a usual care control group (CG, n = 36). After 7 months, supervised WB-EMS training was discontinued, and participants were free to continue WB-EMS independently or engage in alternative exercise modalities. Analyses included only participants who did not continue or newly initiate WB-EMS or resistance training during the subsequent 6-month sustainability period (WB-EMS: n = 21 vs. CG: n = 33). Post-intervention, a significant effect in the primary outcome “pain”, assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS), was observed in favour of the WB-EMS group. However, this difference was no longer significant at the 6-month sustainability follow-up. Likewise, WB-EMS–induced effects were not maintained for most secondary outcomes, including the remaining KOOS subscales, the 7-day pain diary and hip/leg extensor strength. The only exception was the 30-s sit-to-stand test (p &lt; 0.001). Overall, benefits in knee pain and function largely diminished after training cessation, underscoring the importance of long-term exercise adherence.</p>