Knee osteoarthritis is a common cause of disability, affecting more than 650 million people aged 40 and over worldwide in 2020. To relieve pain and improve mobility, some patients use knee orthoses . However, the effectiveness of these devices is not universally agreed upon, and users report widely varying levels of satisfaction.

This study aims to understand how the body responds to these orthoses from a biomechanical perspective, and in particular to quantify the interactions with soft tissues (skin, adipose tissue and muscles). To better understand this interaction, the authors propose to characterize soft tissue behavior on an individual basis using an indentation technique. In practice, this involves pressing on the soft tissues with an ultrasound probe to measure their stiffness at the interface between the leg and the orthosis.

Inclusion Criteria

Participant whose skin is intact on at least one of the two legs, in the tested area.

Participant able to understand simple instructions, conditioning guidelines, and to provide informed consent.

Adult over the age of 50, not under guardianship. Participant having signed the study participation consent form.

Non-inclusion Criteria

Persons covered by articles L. 1121-5 to L. 1121-8 and L. 1122-1-2 (minors, protected adults, etc.) Skin lesions, inflammation, or acute local pain on the tested leg. Neuromuscular pathology preventing controlled muscle contraction. Joint pain preventing the performance of everyday activities (e.g., walking, rising from a chair, climbing stairs…).