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

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

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.

Muscle strength is a key indicator of musculoskeletal health and functional capacity across the lifespan. Handgrip strength, in particular, is widely recognized as a simple and reliable marker of overall strength and health status.

However, normative reference values vary across populations, and limited data exist for adolescents in local or regional contexts.

This observational study will collect handgrip and lower limb strength data using the VALD DynaMo portable dynamometer. The measurements will follow standardized testing positions (American Society of Hand Therapists protocol) to ensure reliability and comparability.

The project will also serve as a pilot for future research on populations with musculoskeletal, neurological, or oncological conditions, where muscle strength is often compromised.

Participation is voluntary, non-invasive, and without associated risk. All data will be anonymized and stored securely for research purposes only.

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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.