Getting a Grip on Strength Measurement in Children (6-13 Y): Impact of Typical Error of Measurement.

ABSTRACT

PURPOSE: To identify the smallest change in handgrip strength (HGS) in children that can be considered of practical significance. METHOD: A total of 290 male and female children, aged 6-13 years, performed a HGS testing protocol 3 times within a 7-day period. The typical error of measurement (TE), coefficient of variation, and smallest worthwhile change (SWC) were calculated for each sex and age group (grade). RESULTS: The TE for the combined group of grade 1 to 7 children was 1.3 kg. Changes in HGS associated with a small change were 1.3 kg, making it difficult for the HGS test to detect these changes. The TE was less than the medium (3.3 kg) and large (5.3 kg) changes in HGS for all the grades and sexes, making changes of these magnitudes more interpretable as they exceed the "noise" (TE) of the measurement. CONCLUSION: Changes in HGS greater than the TE and SWC can be considered real changes of practical significance. This provides researchers with an extra level of analysis when trying to determine the practical relevance of the observed changes.