OActive is looking for volunteers in the following groups: 1. Healthy individuals in high risk of developing OA (HULAFE, Spain), 2. Post-traumatic evaluation of athletes (ANIMUS, Greece), and 3. Elderly people (UNIC, Cyprus) to participate in the research activities of the project. The relevant invitations for participation are included in the download tab under the dissemination material category: https://www.oactive.eu/downloads/dissemination-material/