Examination of reliability and validity in measuring isometric ankle plantar flexion strength using a handheld dynamometer with a belt and metal plate.
Haruka Nakagawa, Munenori Katoh, Saori Arai and 2 others
PMID 39764305WHAT IT FOUND
A handheld dynamometer setup with a belt and metal plate showed good repeatability within examiners but weak agreement between them.
Crucially, it failed to correlate with the gold standard isokinetic dynamometer, meaning it may not accurately measure true ankle strength in males.
Key findings
01Intrarater reliability was high, with ICC values of 0.89 and 0.88 for two examiners, suggesting the same person can get consistent results.
02Interrater reliability was moderate (ICC 0.72), and Bland-Altman analysis showed wide limits of agreement, indicating variability between different examiners.
03Validity against an isokinetic dynamometer was poor, with a Pearson correlation of 0.34 that was not statistically significant.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The validity study included only males, so results may not apply to females. The heel frequently floated off the plate during measurement, which the authors suggest may have affected fixation and accuracy. The sample size for validity was small (22 participants). The study did not test clinical populations, only healthy young adults.
Declared interests
No funding was received, and the authors declared no conflicts of interest.
The easy way to misread this
Do not assume this handheld dynamometer setup is accurate because it is consistent. It showed good repeatability for the same examiner but failed to correlate with the gold standard isokinetic dynamometer, meaning it may measure something other than true ankle strength.