Assessing the Reliability of Handheld Dynamometry and Ultrasonography to Measure Quadriceps Strength and Muscle Thickness in Children, Adolescents, and Young Adults

Abstract

Aims: Muscle strength testing is a core aspect in the pediatric physical and occupational therapy clinical examination and evaluation, and quadriceps muscle strength is associated with the ability to perform gross motor skills. The aim of this study was to assess the reliability of handheld dyamometry (HHD) and ultrasonography to measure quadriceps muscle strength and thickness in children, adolescents, and young adults.

Methods: In 30 participants (6–26 years), without motor impairment, quadriceps strength was measured with HHD in seated and supine with the knee flexed to 90° and 35°. Rectus femoris (RF) and vastus lateralis (VL) muscle thickness was measured using ultrasonography. Typical error of measurement (TEM), coefficient of variation (CV%), and intra-class correlation coefficient (ICC) were used to assess the error and reliability of measures.

Results: The average CV% among three trials of strength testing was 7.07%–9.94% and improved when using the top two trials (4.49%–5.61%). The average TEM was 2.21 Nm for strength and 0.03 cm for muscle thickness. Intra-rater and inter-rater reliability of muscle thickness was good to excellent (0.91–1.00).

Conclusions: The results of this study suggest quadriceps muscle strength and thickness measurements using HHD and ultrasonography are reliable in children, adolescents, and young adults.

Keywords:

• adolescents
• children
• handheld dynamometry
• muscle architecture
• muscle strength
• ultrasonography
• young adults

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contribution

All authors listed were fully involved in the study and the preparation of the manuscript. The material presented here has not been and will not be submitted for publication elsewhere.

Additional information

Funding

This work was supported by the Dr. Gladys E. Wadsworth Physical Therapy Research Fund from the Department of Physical Therapy and Rehabilitation Science within the University of Maryland School of Medicine.

Notes on contributors

Kelly Rock

Kelly Rock, PT, DPT is a board-certified clinical specialist in pediatric physical therapy, PhD student, and Graduate Research Assistant in the Department of Physical Therapy and Rehabilitation Science at the University of Maryland School of Medicine. Dr. Rock has over 11 years of clinical experience as a pediatric physical therapist with research interest in neuromuscular properties and function in children with and without medical conditions.

Christa Nelson

Christa Nelson, PT, DPT, PhD is an Assistant Professor in the Department of Physical Therapy and Rehabilitation Science at the University of Maryland School of Medicine. She is also a board-certified clinical specialist in orthopaedic physical therapy. Dr. Nelson’s research focuses on the use of imaging to quantify musculoskeletal adaptation in various orthopaedic diagnoses, as well as the implications of these changes on rehabilitation and function.

Odessa Addison

Odessa Addison, PT, DPT, PhD is an Assistant Professor in the Department of Physical Therapy and Rehabilitation Science at the University of Maryland School of Medicinee. Dr. Addison's research focuses on the evaluation and treatment of muscle and mobility function in adults with comorbid conditions.

Victoria Marchese

Victoria Marchese, PT, PhD is an Associate Professor and Chair of the Department of Physical Therapy and Rehabilitation Science at the University of Maryland School of Medicine. Dr. Marchese has authored numerous book chapters and peer-reviewed articles in the area of pediatric oncology assessment and physical therapy intervention. Dr. Marchese’s research focuses on examining the neuromotor and musculoskeletal mechanisms that contribute physical performance in children with and without cancer.