High-definition Surface Electromyography Markers for the Diagnosis of Sarcopenia (CHRONOS-SARC)

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 pilot project, the investigators want to explore the potential of the high-definition surface electromyography technology (HD-sEMG) for the diagnosis of sarcopenia. This is a monocentric, descriptive, cross-sectional, parallel group study to develop a new diagnostic method. It is planned to include 50 people aged 75-95 years hospitalized in the acute geriatric ward and suspected of sarcopenia (Score ≥4 on the SARC-F screening questionnaire). The inclusion duration will be 12 months and adding a 1-month patient follow-up as part of routine care, the total study duration will be 13 months. Patients will have their body composition (muscle mass, fat mass, and bone mass) using 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.

The aging of the population is a major public health problem with its multifactorial impact on quality of life and maintenance of autonomy. Unfortunately, one consequence of aging is sarcopenia, which affects the intrinsic and functional properties of muscle. It is a risk factor for loss of autonomy, falls, frailty and is associated with increased mortality. Sarcopenia is defined as a progressive loss of muscle mass, strength and physical performance. Classically, sarcopenia is assessed by imaging techniques (MRI, DEXA) or bioelectrical impedancemetry for aspects related to the assessment of muscle mass loss. MRI or DEXA are not widely available and/or access is limited. For functional aspects, grip strength measurements are often used. Currently sarcopenia cannot be diagnosed and evaluated by a single examination, including both the morphological (muscle mass) and functional aspects. Furthermore, several biological markers are associated with muscle mass, strength, and function, but these biomarkers are not specific to skeletal muscle and are weakly associated with clinical goals. Finally, despite the important interest in assessing the qualitative/functional and quantitative aspect of skeletal muscle in neuromuscular impairment, there is currently no tool that routinely assesses these aspects. In this context, developing new approaches for non-invasive assessment of sarcopenia, is a major issue. In this pilot project, the investigators aim to develop a medical device derived from high-definition surface electromyography (HD-sEMG) technology, non-invasive and portable, for the diagnosis of sarcopenia.

High definition surface electromyography, Sarcopenia, Muscle, Biphotonic X-ray absorptiometry, Dual x-ray absorptiometry (DEXA)

high definition surface electromyography, allowing the recording of muscle activation signals sensitive to the intensity of the contraction and indirectly to the muscle strength as well as to the muscular fatigability, but also capable of measuring the modifications of the recruitment modalities of the motor units. This recording will be made on the rectus femoris during knee extension, either in the lying position or during chair lifts, depending on the patient's functional state.

Muscle Ultrasound with Philips Lumify Wireless Handheld Ultrasound for Android - Model - L12-4 linear probe, allowing performance at the patient's bed.

These signals will be confronted by the diagnosis of sarcopenia defined by the joint presence of the 2 clinical criteria of the European Working Group on Sarcopenia in Older People 2 (EWGSOP2).

HD-sEMG muscle data, measured during lower limb quadriceps extension by High Definition Surface Electromyography HD-sEMG

HD-sEMG parameters will be collected by HD-sEMG technique with TMSi's Mobita equipment, CE marked (European compliance). They will be collected by electrical measurements from a grid of electrodes (32 channels) placed on the muscle surface. The results of the measurement will be represented by a muscle activation mapping.

Rate of participants who deceased at 1 month. Mortality will be measured with vital status at 1 month.

Inclusion Criteria: Patient aged 75 to 95 years Score ≥4 on the SARC-F screening questionnaire Enrolled in a social security plan (no AME) Informed and consenting patient Exclusion Criteria: BMI <18.5 or ≥30 kg/m2 Untreated/unbalanced endocrinological pathology Myopathy Inflammatory or autoimmune pathology Severe psychiatric pathology or severe cognitive disorders that do not allow the performance of examinations Patients who are dependent for all acts of daily life Patients with a very short life expectancy Fracture or trauma in lower limbs during the previous 6 months Bilateral hip prosthesis Skin problem that may interfere with the recording of surface EMG activity Patient under guardianship / curatorship