The ActiControl study is a monocentric, academic, and fully remote observational study designed to build a normative, longitudinal dataset using the Syde® wearable device. The study will enroll 200 healthy volunteers across all age groups, genders, and backgrounds. Participants will be remotely recruited and followed over two years, wearing the Syde® device for 3-week periods every 6 months. All study visits, including consent, data collection, and follow-up, are conducted remotely via phone or video conferencing. The primary objectives are to collect reference data on gait and movement patterns and to assess adherence and acceptability of the device. Secondary objectives include evaluating the reliability of digital endpoints and the influence of demographic and lifestyle factors on these measures.

Rare diseases, though individually uncommon, collectively affect approximately 5% of the European population, with many presenting neurological symptoms and significant societal burden. Clinical trials in this field face challenges such as small sample sizes and subjective outcome measures. To address these limitations, wearable technologies like Syde® and ActiMyo® have been developed to objectively quantify motor function using inertial sensors.

The Syde® device, worn on the wrist and ankle(s), continuously records upper- and lower-limb movements. One of its key metrics, the 95th percentile of stride velocity (SV95C), has been endorsed by the European Medicines Agency as a valid primary outcome in Duchenne Muscular Dystrophy (DMD) trials. Syde® has also been used in studies involving Spinal Muscular Atrophy (SMA), Angelman Syndrome, Facioscapulohumeral Muscular Dystrophy (FSHD), and other neurological conditions, as well as in healthy controls under 20 years old.

To further validate digital outcome measures, normative data across all age groups is essential. The ActiControl study will enroll 200 healthy volunteers (approximately 20 per decade from ages 0 to 90), ensuring balanced representation by gender, ethnicity, and socioeconomic status.

All study procedures are conducted remotely. Participants are recruited and enrolled electronically, including remote signing of the informed consent form. Demographic and health data (e.g., age, sex, height, weight) are collected via phone or video call at inclusion and every 6 months for 2 years. Participants will wear the Syde® device for 3 weeks at five timepoints (baseline, 6, 12, 18, and 24 months).

Primary objectives include:

Building a longitudinal dataset of Syde® digital variables. Assessing adherence and acceptability of the device across age groups.

Secondary objectives include:

Evaluating the reliability of Syde®-derived variables. Investigating the influence of demographic and lifestyle factors (e.g., age, gender, BMI, physical activity, seasonality) on digital endpoints.

Outcome measures include stride velocity, stride length, walking time, step asymmetry, stair climbing metrics, and more.

This study will contribute to the establishment of robust normative data, enabling more accurate interpretation of digital biomarkers in future clinical trials for rare and neurological diseases.

Inclusion Criteria:

• Male and female of different age groups
• Signed informed consent form by participant him/herself or, in case of patients <18 years old, signed informed consent form by patient's parents or legal guardians
• Able to ambulate (minimum 10 meters without help)
• Participant willing and able to comply with all study procedures

Exclusion Criteria:

• Patients who have undergone a surgical procedure or who have experienced recent trauma (within fewer than 6 months) affecting the upper or lower limbs
• Elite athletes (at the national level)
• Pregnant women
• A chronic or acute muscular, neurological, infectious, or inflammatory pathology within the 3-week period immediately prior to inclusion
• An orthopedic, neuromuscular, or neurological pathology that affects the quality of the participant's walking gait
• No access to unlimited internet connection or alternatively no capacity to come on-site to upload Syde data