frAGILE: does function follow form in young and old adults in immobilization and retraining?
Investigating the effects of unilateral lower limb immobilization and re-training in healthy young and older men and women.
Current interventions as of 05/11/2025: Participants will undergo 10 days of unilateral lower limb suspension using a sling to restrict movements and simulate muscle disuse. During this period, participants will be provided with crutches and instructed to avoid using the immobilized leg. Compliance will be monitored using accelerometers and activity logs. Following immobilization, participants will complete 3 weeks of supervised retraining, consisting of resistance exercises targeting the immobilized leg. Training sessions will take place at the University of Basel and will focus on strength and neuromuscular activation. The training intensity will be progressively adapted based on individual performance assessments. Assessments of muscle strength, balance, gait, neuromuscular activation, and muscle structure will be conducted before and after immobilization, as well as throughout the retraining phase. _____ Previous interventions: Participants will undergo 10 days of unilateral lower limb immobilization using a cast to restrict movements and simulate muscle disuse. During this period, participants will be provided with crutches and instructed to avoid using the immobilized leg. Compliance will be monitored using accelerometers and activity logs. Following immobilization, participants will complete 3 weeks of supervised retraining, consisting of resistance exercises targeting the immobilized leg. Training sessions will take place at the University of Basel and will focus on strength and neuromuscular activation. The training intensity will be progressively adapted based on individual performance assessments. Assessments of muscle strength, balance, gait, neuromuscular activation, and muscle structure will be conducted before and after immobilization, as well as throughout the retraining phase.
Current key inclusion criteria as of 28/07/2026: 1. Healthy men and women aged 18 to 30 years (young) as well as older adults (60-74 years) - active persons performing 1-3 active sessions per week 2. Willing and physically able to undergo the study demands (immobilization period and retraining exercises) 3. Daily tasks should not require them to be physically active during the immobilization period 4. Be able to travel to the facilities of the Department of Sports, Exercise and Health, University of Basel for the measurement sessions and three times per week to complete the retraining period 5. Be able to travel 5 times to the Department of Sports, Exercise and Health and to the University Hospital Basel for the measurement sessions 6. All participants will receive a medical examination and need medical clearance for participation 7. Signed informed consent _____ Previous key inclusion criteria as of 05/11/2025: 1. Healthy men and women aged 18 to 30 years (young) as well as older adults (60-70 years) - active persons performing 1-3 active sessions per week 2. Willing and physically able to undergo the study demands (immobilization period and retraining exercises) 3. Daily tasks should not require them to be physically active during the immobilization period 4. Be able to travel to the facilities of the Department of Sports, Exercise and Health, University of Basel for the measurement sessions and three times per week to complete the retraining period 5. Be able to travel 5 times to the Department of Sports, Exercise and Health and to the University Hospital Basel for the measurement sessions 6. All participants will receive a medical examination and need medical clearance for participation 7. Signed informed consent _____ Previous key inclusion criteria: 1. Age Groups: Young adults (18-35 years) and older adults (>65 years). 2. Health Status: Primarily healthy individuals living independently in the community. 3. Physical Ability: Participants must be phys
Current key exclusion criteria as of 05/11/2025: 1. History of cardiovascular, pulmonary or chronic inflammatory disease 2. Personal or family history of blood clots 3. Orthopaedic problems or surgery (within the last 6 months) 4. Body mass index >35 kg/m2 5. Pregnancy 6. History of osteoporosis or a recent (past 6 months) low‐trauma fracture 7. Use of assistive walking device within the previous year 8. Expecting to travel abroad throughout the intervention 9. Participants who do not agree to the collected data being made available in coded form (open science) 10. History of cancer within the past 5 years 11. Current use of oral contraceptives with esrtogen or oestrogenic hormone therapy 12. Usual contraindications to MRI as defined in the clinical practice _____ Previous key exclusion criteria: 1. Medical Conditions: 1.1. History of cardiovascular, pulmonary, or chronic inflammatory diseases. 1.2. Personal or family history of blood clots. 1.3. Allergy to heparin (used for anticoagulation during immobilization). 2. Orthopedic Issues: 2.1. Recent orthopedic surgery (within the last six months). 2.2. Existing orthopedic problems that could interfere with participation. 3. Body Composition: 3.1. Body mass index (BMI) > 30 kg/m². 4. Bone Health: 4.1. History of osteoporosis. 4.2. Recent (past six months) low-trauma fracture. 5. Mobility and Functional Restrictions: 5.1. Use of assistive walking devices within the previous year. 5.2. Expectation of travel during the intervention period. 6. Pregnancy: 6.1. Pregnant individuals will be excluded.