The twofold goal of this study is to understand the link between muscle power, muscle strength, and muscle control degradation with the risk of falling, and to develop a framework for the comprehensive and quantitative assessment of muscle power (and strength) in an elderly population of patients with knee osteoarthritis, who are at higher risk of falling. The main question it aims to answer is: ● Are muscle power and motor control degradation better predictors of falls than muscle strength in the aging population? Participants will undergo: * Muscle force assessment on a dynamometer * Muscle power assessment on a dynamometer and on isntrumented stairs * Home-based mobility monitoring * Full lower limb MRI acquisition * Gait assessment