Reliability of Quantitative Muscle Testing in Healthy Children and in Children with Duchenne Muscular Dystrophy Using a Hand-held Dynamometer

Abstract

The purpose of this study was to examine intratester and test-retest reliability using a hand-held dynamometer for the measurement of isometric muscle strength in 28 healthy children and children with Duchenne muscular dystrophy. The Dystrophic Group consisted of 14 children diagnosed with Duchenne muscular dystrophy, and the Healthy Group consisted of 14 age-matched children with no history of orthopedic or neuromuscular disorders. One physical therapist tested hip and knee extension, elbow flexion, and shoulder abduction in each child bilaterally. A two-way analysis of variance for repeated measures was used to analyze differences between measurements taken within and across the testing sessions. Pearson product-moment correlation coefficients were determined on mean values across the testing sessions for each variable. No significant differences (p greater than .05) between measurements taken within or across testing sessions were found in either the Dystrophic Group or the Healthy Group. Correlation coefficients for the Dystrophic Group ranged from .83 to .99 for the variables tested. Correlation coefficients for the Healthy Group ranged from .74 to .99. The results suggest that the hand-held dynamometer can be used as a reliable instrument in measuring the isometric strength of selected muscles in children.

Hand‐held dynamometry for muscle strength measurement in children with cerebral palsy

“…9 Testing maximum strength of the stronger muscles may be limited by the upper limits of the dynamometer 9 or the ability of the tester to resist the force adequately. 20 However, children with CP demonstrate significant power deficits in ankle plantarflexors during gait. 21 Despite the assumption in this study that the examiner could easily apply resistance, measuring ankle plantarflexor strength using the dynamometer was difficult, particularly on the less impaired side.…”

Enhancing the examiner’s resisting force improves the reliability of manual muscle strength measurements: Comparison of a new device with hand-held dynamometry

“…Each subject was tested 3 times per examiner, muscle group and device, with a random order of the test conditions. All subjects performed stretching exercises to warm up the testing muscles before the tests, and were then seated with the knee and hip flexed to 90° (9,(22)(23)(24), while the trunk, thigh and leg segments were stabilized using straps. The dynamometer pad was placed on the anterior surface of the lower leg, approximately 1 cm proximal to the ankle joint.…”

Validity of Isometric Muscle Strength Measurements of the Lower Limbs Using a Hand-held Dynamometer and Belt: a Comparison with an Isokinetic Dynamometer

“…However, this method requires the examiner to have sufficient strength to hold the HDD steady, which can be difficult when measuring isometric muscle strength of the lower limbs, especially when the subject is strong and the examiner weak. The limit of the manual resistance was reported to be from 220 to 294.2 N (30 kg) in previous studies [1][2][3][4][5][6] . Methods previously reported for fixing a HHD to overcome this problem and prevent the angle of the joint from changing include using a stick 7) , a steel support 8) , and a belt [9][10][11][12][13][14][15] .…”