Prospective Cohort Study Evaluating a Thermal Spa Programme in Symptomatic Knee Osteoarthritis

Knee osteoarthritis is a common cause of pain, functional limitation, and reduced quality of life in older adults. Thermal spa treatment is widely used as a non-pharmacological intervention for the management of osteoarthritis symptoms, but its effects on joint movement and motor control remain insufficiently characterized using objective biomechanical measures. This study aims to evaluate the effects of a 3-week thermal spa treatment on knee joint movement in patients with knee osteoarthritis. Movement analysis will be performed using wearable inertial sensors (Xsens) placed on the lower limbs to quantify kinematic and spatiotemporal gait parameters during standardized functional tasks. The primary outcome will assess changes in knee movement fluidity during walking, quantified using normalized angular jerk in the sagittal plane. Secondary outcomes will include changes in pain intensity, osteoarthritis symptoms, physical activity level, and health-related quality of life assessed using validated questionnaires. In addition, blood samples will be collected before and after the intervention to explore transcriptomic changes associated with the treatment. Assessments will be conducted at baseline, immediately after the spa treatment, and during follow-up visits at 3 and 12 months.