In a randomized controlled trial (RCT) design, this study seeks to investigate potential added benefits of supplementing NEMEX and education with focused knee extensor strength training in patients with knee-OA. 90 patients deemed ineligible for knee replacement surgery will be recruited from the ambulatory setting at Naestved Hospital. By random allocation, patients will be recruited to either 12 weeks (twice weekly) of NEMEX and education + focused knee extensor strength training (intervention group) or 12 weeks (twice weekly) of NEMEX and education only (control group).