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Updated: Aug 19, 2026
Isometric and Eccentric Force Generation Assessment of Skeletal Muscles Isolated from Murine Models of Muscular Dystrophies
Published on: January 31, 2013
Measurement of isometric force in children with and without Duchenne's muscular dystrophy
C M Brussock1, S M Haley, T L Munsat
1Neuromuscular Research Unit, New England Medical Center, Boston, MA 02111.
Insights
This study found that an electronic strain gauge provides consistent measurements of maximal isometric force in children, including those with Duchenne muscular dystrophy (DMD). This reliable method aids in assessing muscle strength in pediatric populations.
Area of Science:
- Pediatric Neuromuscular Research
- Biomedical Engineering
- Rehabilitation Science
Background:
- Assessing maximal isometric force is crucial for monitoring neuromuscular function in children.
- Duchenne muscular dystrophy (DMD) significantly impacts muscle strength, necessitating reliable measurement tools.
- Existing methods for force measurement in pediatric populations may lack consistency.
Purpose of the Study:
- To evaluate the reproducibility of maximal isometric force measurements in children using an electronic strain gauge.
- To assess the consistency of measurements across different muscle groups, test occasions, and sides of the body.
- To determine the reliability of this protocol in children with and without Duchenne muscular dystrophy (DMD).
Main Methods:
- Adapted a standardized protocol from the Tufts Quantitative Neuromuscular Examination for isometric force testing.
- Recruited ten children with DMD and ten age-matched healthy children.
- Utilized a generalizability framework and three-way ANOVA to analyze measurement variations (group, side, occasion) and intertester reliability.
Main Results:
- A significant group effect was observed for all muscle groups, indicating differences between children with and without DMD.
- No significant main effects were found for test side or occasion, suggesting consistency.
- High test-retest intraclass correlation coefficients (ICCs) were reported (0.85–0.99) for both groups.
- Intertester ICCs were also high (0.71–0.98), indicating good reliability between testers.
Conclusions:
- The electronic strain gauge protocol demonstrates reproducible maximal isometric force measurements in seven muscle groups for children with and without DMD.
- This method offers a reliable tool for quantitative neuromuscular assessment in pediatric populations.
- The findings support the use of this protocol for clinical and research applications involving pediatric muscle strength evaluation.
Abstract:
The purpose of this study was to examine the consistency of measurements of maximal isometric force production in children using an electronic strain gauge. A standardized protocol of force testing from the Tufts Quantitative Neuromuscular Examination was adapted to obtain isometric force measurements in seven muscle groups bilaterally. Ten children with Duchenne's muscular dystrophy (DMD) and 10 age-matched children without DMD were recruited for the study. A generalizability framework was used to examine variations in measurements attributable to group differences, test occasions within the same day, and extremity side. Intertester reliability estimates were also completed on a subsample of children with and without DMD. A three-way analysis of variance between groups, sides, and test occasions demonstrated a significant group main effect for all muscle groups. In general, significant main effects were not present for side or test occasion. Test-retest intraclass correlation coefficients (ICCs) for all muscle groups ranged from .88 to .99 for the children with DMD and from .85 to .98 for the children without DMD. Intertester ICCs were slightly lower, ranging from .74 to .97 for the children with DMD and from .71 to .98 for the children without DMD. The results indicate that the electronic strain-gauge protocol produces reproducible force measurements in seven selected muscle groups in children with and without DMD. Brussock CM, Haley SM, Munsat TL, Bernhardt DB. Measurement of isometric force in children with and without Duchenne's muscular dystrophy.
