Sarcopenia is a progressive and generalised skeletal muscle disorder involving the accelerated loss of muscle mass and function that is associated with increased adverse outcomes including falls, functional decline, frailty, and mortality. In this project, the high-definition surface electromyography technology (HD-sEMG) signals will be analysed to extract features/ markers for the diagnosis of sarcopenia. This is a multicentric, descriptive, cross-sectional, parallel group study to develop a new diagnostic method. It is planned to include 846 people aged 75 years and over hospitalized in the acute geriatric or rehabilitation wards and suspected of sarcopenia (Score ≥4 on the SARC-F screening questionnaire). The inclusion duration will be 18 months and adding a 3-month patient follow-up. The total study duration will be 21 months. Patients will have their body composition using bioimpedancemetry and if possible by dual X-ray absorptiometry (DEXA). Muscular strength will be assessed by handgrip strength. Physical performance will be assessed. Additional data will be collected from their medical records.