Isometric muscle torque in Chilean children and adolescents evaluated by manual maintenance dynamometry: a reliability study

The measurement of isometric muscle torque with hand-held dynamometry is a technique little studied in the pediatric setting for the evaluation of maximal isometric muscle strength. Objective: to determine the reliability of hand-held dynamometry to obtain the maximal isometric torque of upper and lower limb muscle groups in Chilean children and adolescents. Patients and Methods: Crosssectional study. Seventy-two participants aged between 7 and 15 years were selected from a school in Talca. Maximal isometric torque was recorded in 15 muscle groups of upper and lower limbs through hand-held dynamometry. Intra- and inter -rater evaluation was used, applying the intraclass correlation coefficient (ICC) to determine the reliability of the tests and Bland -Altman plots to evaluate concordance. Results: The results demonstrated good to excellent inter -rater reliability (ICC = 0.850.98) and intra-rater reliability (ICC = 0.87-0.98). Only two groups, hip extensors and abductors, showed good inter -rater reliability (ICC = 0.85 and ICC = 0.88, respectively); and one group, the ankle dorsiflexors, showed good intra-rater reliability (ICC = 0.87). 100% of the tests presented at least 95.8% inter- and intra-rater agreement on the Bland -Altman plots. Conclusion: The evaluation of isometric muscle torque using hand-held dynamometry is a reliable procedure for use in different growth periods.