Healthy Adult, Muscle Strength, Skeletal Muscle Ultrasound
Conditions
Keywords
Muscle ultrasound, Skeletal muscle ultrasonography, Muscle biomarkers, Isometric quadriceps muscle strength, Handgrip, Muscle thickness, Echo intensity, Muscle quality, Predictive models
Brief summary
This observational study aims to determine whether ultrasound-derived muscle biomarkers can predict isometric quadriceps muscle strength and handgrip in healthy adults aged 18-89 years. The main questions it aims to answer are: * Which ultrasound muscle characteristics are associated with isometric quadriceps muscle strength and handgrip? * Can ultrasound-derived biomarkers be used to develop predictive models of muscle strength in healthy adults? Participants will undergo: * Ultrasound assessment of the quadriceps and forearm flexor muscles; * Measurement of isometric quadriceps muscle strength and handgrip using standardized dynamometry protocols; * Assessment of functional capacity, mobility and balance; * Completion of questionnaires related to health status, physical activity, nutrition, fatigue and health-related quality of life. The study will also assess the reliability of ultrasound measurements and explore the relationship between ultrasound variables, muscle strength, physical function and health-related factors.
Detailed description
Peripheral muscle strength is an important determinant of physical function, independence and health outcomes. Reduced quadriceps muscle strength and handgrip have been associated with functional limitations, frailty, hospitalization and mortality. Although muscle ultrasound is increasingly used to assess muscle morphology and quality, its ability to predict muscle strength remains incompletely understood. The MUSCLE-US study is a monocentre observational study designed to investigate the relationship between ultrasound-derived muscle biomarkers and isometric quadriceps muscle strength and handgrip in healthy adults. Participants aged 18-89 years will be recruited from community settings and stratified by age and sex. Ultrasound assessments will be performed on the quadriceps and forearm flexor muscles using standardized acquisition procedures. First-order variables (e.g., muscle thickness, cross-sectional area, pennation angle, fascicle length), second-order texture features and higher-order ultrasound biomarkers will be extracted and analysed. Isometric quadriceps muscle strength and handgrip will be measured using standardized dynamometry protocols. Additional assessments will include functional capacity tests, mobility and balance measures, physical activity, nutritional status, fatigue, dyspnoea, health-related quality of life, lifestyle factors and comorbidity profiles. The primary objective is to identify ultrasound biomarkers associated with quadriceps muscle strength and handgrip, and to develop predictive models of muscle strength. Secondary objectives include assessment of ultrasound measurement reliability and exploration of relationships between ultrasound biomarkers, muscle strength, physical function and health-related characteristics. Recruitment, assessor training, ultrasound standardisation procedures and reliability analyses will be conducted during the initial phase of the project, followed by the main recruitment and data collection phase and subsequent statistical modelling and dissemination activities.
Interventions
None listed
Sponsors
University of Alcala
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 89 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy adults aged 18-89 years. * Resident in Spain for at least 5 years. * Living independently in the community and able to complete all study assessments. * Able to understand and follow verbal instructions in Spanish. * Able and willing to provide written informed consent prior to study participation.
Exclusion criteria
* Neurological, musculoskeletal, or systemic disorders affecting muscle strength or mobility. * Recent surgery or acute injury affecting the upper or lower limbs. * Recent use of medications affecting the musculoskeletal system (e.g., systemic corticosteroids for \>1 week during the previous 6 months or muscle relaxants during the previous week). * Cognitive or psychiatric conditions limiting participation. * Pregnancy. * Recent postpartum period (≤3 months after delivery). * Presence of clinically relevant pain, fatigue, physical deconditioning, or functional limitations that may interfere with study procedures or measurement validity. * Acute illness at the time of assessment. * Uncontrolled hypertension (≥140/90 mmHg). * Resting peripheral oxygen saturation ≤90%. * Moderate-to-severe pain (Numeric Rating Scale ≥4/10). * Any medical condition considered by the investigator to contraindicate study participation.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Isometric quadriceps muscle strength | Day 1 | Quadricpes maximal voluntary contraction measured using a handheld dynamometer according to a standardized testing protocol. Peak force will be recorded in kilograms-force (kgf). |
| Handgrip | Day 1 | Maximal voluntary handgrip measured using a hydraulic hand dynamometer according to the American Society of Hand Therapists protocol. Peak force will be recorded in kilograms-force (kgf). |
| Ultrasound-derived muscle biomarkers | Day 1 | Muscle ultrasound biomarkers obtained from standardized B-mode ultrasound images of selected quadriceps and forearm muscles. Candidate variables include muscle morphology, architecture, grayscale characteristics and texture-based parameters. The final set of ultrasound-derived biomarkers will be defined following assessor training, protocol standardization and pilot reliability analyses. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Five-repetition sit-to-stand test | Day 1 | Functional capacity assessed by the time required to complete five sit-to-stand repetitions according to standardised procedures. Results will be expressed in seconds. Lower values indicate better lower-limb functional capacity. |
| One-minute sit-to-stand test | Day 1 | Functional capacity assessed as the number of sit-to-stand repetitions completed in one minute according to standardised procedures. Higher values indicate better functional exercise capacity. |
| Timed Up and Go test | Day 1 | Mobility and dynamic balance assessed using the Timed Up and Go test. Results will be expressed in seconds. Lower values indicate better mobility and dynamic balance. |
| Modified Medical Research Council dyspnoea scale | Day 1 | Dyspnoea severity assessed using the modified Medical Research Council dyspnoea scale. Scores range from 0 to 4, with higher scores indicating greater breathlessness. |
| Modified Borg dyspnoea scale | Day 1 | Perceived breathlessness assessed using the modified Borg dyspnoea scale. Scores range from 0 to 10, with higher scores indicating greater breathlessness. |
| Dyspnoea-12 | Day 1 | Dyspnoea assessed using the Dyspnoea-12 questionnaire. The total score ranges from 0 to 36, with higher scores indicating more severe breathlessness. |
| Functional Assessment of Chronic Illness Therapy-Fatigue | Day 1 | Fatigue assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire. Scores range from 0 to 52, with higher scores indicating less fatigue. |
| EuroQol 5-Dimension 5-Level | Day 1 | Health-related quality of life assessed using the EuroQol 5-Dimension 5-Level (EQ-5D) questionnaire. The index score will be calculated according to the appropriate national value set. Higher scores indicate better health status. Self-rated health assessed using the EQ-5D Visual Analogue Scale. Scores range from 0 to 100, with higher scores indicating better perceived health. |
| International Physical Activity Questionnaire-short form | Day 1 | Physical activity assessed using the International Physical Activity Questionnaire-short form. Results will be expressed as minutes per week spent in vigorous/moderate/total physical activity, time per week spent walking and hours per day spent in sedentary behaviour (sitting). |
| Mini Nutritional Assessment-short form | Day 1 | Nutritional status assessed using the Mini Nutritional Assessment-short form. Scores range from 0 to 14, with higher scores indicating better nutritional status. |
Contacts
CONTACTNicola S. Diciolla, PT, Ph.D.
CONTACTBeatriz Sánchez-Sánchez, PT, Ph.D.
PRINCIPAL_INVESTIGATORNicola S. Diciolla, PT, Ph.D.
University of Alcalá
Outcome results
None listed