Reference Values and Reliability of Handgrip Strength Assessment Using a Digital Dynamometer in Healthy Adolescents and Other Populations: A Pilot Observational Study

NCT07408986 | Completed

• 1 other identifier: 061125
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

his study aims to establish reference values and examine the reliability of handgrip strength assessment using a digital dynamometer (VALD DynaMo) in healthy adolescents. Participants will undergo standardized strength evaluations of upper and lower limbs, following international testing guidelines. Descriptive variables such as age, sex, height, weight, hand dominance, and physical activity level will also be recorded. The results will contribute to developing normative data and validating the use of portable dynamometry for musculoskeletal health assessment, with potential future applications in clinical populations.

Conditions

Muscle Strength; Reliability; Digital Handgrip Dynamometry; Adolescents; Healthy Participants

Keywords

Muscle Strength; Hand Strength; Physical Fitness; Adolescent; Reference Values; Reproducibility of Results; Musculoskeletal System

Outcome Measures

Primary Outcomes (1)

• Maximal Isometric Muscle Strength (Handgrip and Lower Limb)

  Peak isometric force (in Newtons or kilograms) recorded using a VALD Dynamo® handheld digital dynamometer. Measurements will follow standardized positioning protocols recommended by the American Society of Hand Therapists (ASHT) for upper limb and by recent literature for lower limb testing. Each participant will perform three maximal voluntary contractions per muscle group, with the highest value recorded for analysis. Unit of Measure: Newtons (N) or Kilograms.

  Single testing session (baseline).

Secondary Outcomes (3)

• Test-Retest Reliability of Muscle Strength Measures. Maximal Isometric Muscle Strength Handgrip

  Two sessions separated by 7-14 days.

• Descriptive Anthropometric and Activity Variables

  Collected at baseline (single session).

• Clinical Applicability (Optional Future Arm). Maximal Isometric Muscle Strength (Handgrip)

  To be determined in future phases

Study Arms (2)

Healthy Adolescent Group

A single group of healthy adolescents will participate in the study. Each participant will undergo standardized assessments of upper and lower limb muscle strength using digital dynamometry. No treatment or intervention will be applied.

Diagnostic Test: Muscle Strength Assessment using Digital Handheld Dynamometry (VALD Dynamo®)

Clinical Population Group (Future Recruitment)

This group may include participants with musculoskeletal, neurological, or oncological conditions in future phases of the study. The same standardized dynamometry protocol will be applied to compare muscle strength profiles and assess the applicability of the measurement tools in clinical populations.

Diagnostic Test: Muscle Strength Assessment using Digital Handheld Dynamometry (VALD Dynamo®)

Interventions

Muscle Strength Assessment using Digital Handheld Dynamometry (VALD Dynamo®) DIAGNOSTIC_TEST

All participants (healthy or clinical) will perform standardized muscle strength tests using the VALD Dynamo® digital dynamometer. For upper limb assessments, the protocol will follow the American Society of Hand Therapists (ASHT) recommendations (shoulder neutral, elbow 90°, forearm neutral, wrist 0-30° extension, 0-15° ulnar deviation). Lower limb tests will include validated isometric protocols for major muscle groups (quadriceps, hamstrings, hip abductors/adductors). Each test will include three maximal voluntary contractions (3 seconds each) with 60 seconds of rest between trials. Data will be used to analyze intra- and inter-session reliability, normative reference values, and potential clinical applicability.

Clinical Population Group (Future Recruitment); Healthy Adolescent Group

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study will include healthy adolescent students (initially aged 15-16 years) from local educational centers collaborating with the University of Extremadura. Participants will undergo non-invasive strength assessments using handheld dynamometry to establish normative reference values. In future phases, the study population may be expanded to include clinical cohorts (e.g., patients with musculoskeletal, neurological, or oncological pathologies) to explore the applicability of dynamometry in clinical assessment and rehabilitation contexts.

You may qualify if:

• Healthy adolescents aged 15-16 years (for the current phase).
• Ability to understand and follow verbal instructions.
• Written informed consent provided by parent or legal guardian (for minors).
• Assent given by the adolescent participant.
• In future extensions: individuals aged 10-80 years, including those diagnosed with musculoskeletal, neurological, or oncological conditions, able to safely perform isometric contractions.

You may not qualify if:

• History of acute or chronic upper or lower limb injury in the last 6 months.
• Neurological, cardiovascular, or systemic disorders that may limit maximal effort.
• Current pain, inflammation, or post-surgical condition affecting muscle performance.
• Cognitive or communication impairments preventing valid testing.
• Refusal or withdrawal of informed consent at any point.

Sponsors & Collaborators

• University of Extremadura: lead

Study Sites (1)

Facultad de Medicina y Ciencias de la Salud. Avenida de Elvas s/n

Badajoz, Badajoz, 06006, Spain

Location

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Investigator

Study Record Dates

• First Submitted: February 3, 2026
• First Posted: February 13, 2026
• Study Start: November 6, 2025
• Primary Completion: November 6, 2025
• Study Completion: January 31, 2026
• Last Updated: February 13, 2026

Record last verified: 2026-02

Locations

ES (1)