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Commentary on “Isometric Muscle Strength in Youth Assessed by Hand-held Dynamometry: A Feasibility, Reliability, and Validity Study”

Nervik, Deborah PT, MHS, DPT, DHS, PCS; Nicols, Jennifer Parent MSPT, DPT

Pediatric Physical Therapy: October 2011 - Volume 23 - Issue 3 - p 300
doi: 10.1097/PEP.0b013e318228c546
Clinical Bottom Line

Franklin Pierce University Concord, New Hampshire

Private Practice Milford, New Hampshire

The authors declare no conflicts of interest.

“How should I apply this information?”

As pediatric therapists, we are consistently looking for valid, reproducible, and objective ways to measure the strength of our clients. Traditional methods of manual muscle testing and Cybex strength testing have their limitations. The validity of manual muscle testing is especially questionable with younger children and is often compromised by the subjectivity between assignments of strength grades 4 and 5. Cybex equipment is costly and requires user training and space for housing. With these clinical challenges in mind, inexpensive, easily accessible, hand-held dynamometer (HHD) devices may provide a promising alternative. This study demonstrates that using HHD for assessing strength has acceptable inter- and intrarater reliability and concurrent validity with values found with Cybex testing for most muscle groups that were tested. This is not only valuable for clinical practice, but essential for evidenced-based research. In addition, insurers often want concrete proof of intervention effectiveness, which HHD values could provide. Finally, the protocol developed in this study offers therapists specific guidelines for use of HHD in the pediatric client, which has been lacking in the literature.

“What should I be mindful about in applying this information?”

The obvious question that exists for any testing that we may undertake as therapists is “does this translate into meaningful, useful information that will assist with return to or maximize function for my patient?” As the positions tested were antigravity, we must consider how conducting strength testing in this position affects our ability to extrapolate the information into meaningful, useful information in determining functional status and prospective interventions.

As with any research, limitations are present. Unfortunately, validity and reliability in this study was not examined for the subjects younger than 13 years, which limits its application for children of all ages. In addition, a few key muscle groups (ankle dorsiflexion, plantarflexion, hip abduction, hip extension) lacked good validity and reliability. These muscle groups are critical for important functional activities such as gait. Other limitations were small sample size and lack of norms. And finally, if this protocol was to be implemented by other therapists, would it be necessary to undergo the same training as was done in this study? This may not be feasible.

Deborah Nervik, PT, MHS, DPT, DHS, PCS

Franklin Pierce University

Concord, New Hampshire

Jennifer Parent Nicols, MSPT, DPT

Private Practice

Milford, New Hampshire

Copyright © 2011 Academy of Pediatric Physical Therapy of the American Physical Therapy Association