Reference Equations and Normative Data for Isometric Quadriceps and Handgrip Muscles STrength in Southern European Populations - RESTart: a Multicentre Study

This observational study aims to learn about peripheral muscle strength in healthy adults and people with chronic respiratory diseases. The study aims to develop reference data for quadriceps muscle strength and handgrip in adults living in Southern Europe and to assess whether these reference data can be used in people with chronic respiratory diseases. The main questions it aims to answer are: * What are the normal values for quadriceps and handgrip muscle strength in healthy adults aged 18-89 years living in Spain, Portugal and Italy? * Can the reference values developed in healthy adults be applied to people with chronic respiratory diseases? Participants will attend one study visit. During this visit, researchers will: * Measure quadriceps muscle strength and handgrip. * Collect information about age, sex, height, weight and other health characteristics. * Perform simple functional tests related to mobility and physical performance. * Ask participants to complete questionnaires about symptoms, physical activity and health-related quality of life.

NCT Number	NCT07628530
Lead Sponsor	University of Alcala
Conditions	Muscle Strength, Healthy, Chronic Respiratory Diseases
Enrollment	2,815 participants
Start Date	2026-06
Primary Completion	2029-06 (estimated)
Study Completion	2030-06 (estimated)
Updated on ClinicalTrials.gov	2026-06-08