An observational study in Healthy Adult, Muscle Strength and Skeletal Muscle Ultrasound, sponsored by University of Alcala. Not yet recruiting. Open to participants aged 18 Years to 89 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-16.
Sponsored by University of Alcala · Observational
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:
Participants will undergo:
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.
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.
University of Alcala is the lead sponsor of 128 studies on the registry; 36 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Community-dwelling healthy adults aged 18-89 years residing in Spain. Participants will be recruited through community advertisements, institutional dissemination channels, and collaborating centres. The study aims to investigate the relationship between ultrasound-derived muscle biomarkers and isometric quadriceps muscle strength and handgrip in a healthy adult population.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy/community-dwelling adults aged 18-89 years participating in an observational study evaluating ultrasound-derived muscle biomarkers and their relationship with isometric quadriceps muscle strength and handgrip.
Isometric quadriceps muscle strength
Quadricpes maximal voluntary contraction measured using a handheld dynamometer according to a standardized testing protocol. Peak force will be recorded in kilograms-force (kgf).
Time frame: Day 1
Handgrip
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).
Time frame: Day 1
Ultrasound-derived muscle biomarkers
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.
Time frame: Day 1
Five-repetition sit-to-stand test
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.
Time frame: Day 1
One-minute sit-to-stand test
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.
Time frame: Day 1
Timed Up and Go test
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.
Time frame: Day 1
Modified Medical Research Council dyspnoea scale
Dyspnoea severity assessed using the modified Medical Research Council dyspnoea scale. Scores range from 0 to 4, with higher scores indicating greater breathlessness.
Time frame: Day 1
Modified Borg dyspnoea scale
Perceived breathlessness assessed using the modified Borg dyspnoea scale. Scores range from 0 to 10, with higher scores indicating greater breathlessness.
Time frame: Day 1
Dyspnoea-12
Dyspnoea assessed using the Dyspnoea-12 questionnaire. The total score ranges from 0 to 36, with higher scores indicating more severe breathlessness.
Time frame: Day 1
Functional Assessment of Chronic Illness Therapy-Fatigue
Fatigue assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire. Scores range from 0 to 52, with higher scores indicating less fatigue.
Time frame: Day 1
EuroQol 5-Dimension 5-Level
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.
Time frame: Day 1
International Physical Activity Questionnaire-short form
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).
Time frame: Day 1
Mini Nutritional Assessment-short form
Nutritional status assessed using the Mini Nutritional Assessment-short form. Scores range from 0 to 14, with higher scores indicating better nutritional status.
Time frame: Day 1
Age
Participant age recorded in completed years.
Time frame: Day 1
Weight
Participant weight recorded in kilograms.
Time frame: Day 1
Height
Participant height recorded in metres.
Time frame: Day 1
Body mass index
Body mass index calculated as weight divided by height squared.
Time frame: Day 1
Sex
Participant biological sex recorded as female or male.
Time frame: Day 1
Systemic inflammation markers
CRP, IL-6, eosinophils, fibrinogen, neutrophil elastase, ESR, KL-6, SP-D, FeNO, IgE, calprotectin, if available, from medical records.
Time frame: Day 1
Charlson Comorbidity Index
Comorbidity burden assessed using the Charlson Comorbidity Index. Higher scores indicate greater comorbidity burden.
Time frame: Day 1
Anatomical Therapeutic Chemical (ATC) Classification System
Current medication use classified according to the Anatomical Therapeutic Chemical (ATC) Classification System.
Time frame: Day 1
Smoking Exposure (pack-year index)
Lifetime smoking exposure quantified using the pack-year index, calculated from self-reported smoking history. A higher pack-year index means greater cumulative exposure to tobacco smoking over lifetime.
Time frame: Day 1
Alcohol Use Disorders Identification Test-Consumption
Alcohol consumption assessed using the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C). Higher scores indicate greater alcohol consumption and increased risk of hazardous drinking.
Time frame: Day 1
No study locations are listed for this record.
Plan to share: Yes — Individual participant data (IPD) that underlie the results reported in publications, after de-identification, will be made available. Shared data may include demographic characteristics, anthropometric variables, isometric quadriceps muscle strength, handgrip, ultrasound-derived muscle variables, functional capacity measures, and patient-reported outcomes/questionnaire data collected as part of the study. Direct identifiers will be removed before data sharing. Data sharing will comply with applicable ethical approvals, informed consent provisions, and data protection regulations.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Analytic code
Time frame: De-identified individual participant data and supporting documents will become available beginning 12 months after publication of the primary study results and will remain available for at least 5 years thereafter.
Access criteria: Researchers who provide a methodologically sound proposal for secondary analyses or validation studies may request access to the de-identified dataset. Requests will be reviewed by the study investigators. Data will be provided following approval of the proposal and execution of a data-sharing agreement, when required, in accordance with ethical and legal requirements. Supporting documents, including the study protocol, statistical analysis plan, informed consent form template, and analytic code, will be made available upon reasonable request.
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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