Reliability of measurement using Image J for reach distance and movement angles in the functional reach test.
Takayuki Suzuki, Hiroyuki Hashisdate, Yuhki Fujisawa and 4 others
PMID 33642684WHAT IT FOUND
Image J software reliably measures both reach distance and joint angles during the functional reach test.
For healthy young men, a change of more than 18.3 mm in distance or 2.6 degrees in trunk angle is likely real improvement rather than measurement error.
Key findings
01The software showed good to excellent agreement between two measurements taken on the same day for both distance and angles.
02The smallest change that can be considered real, rather than measurement noise, is 18.3 mm for reach distance and 2.6 degrees for the trunk angle.
03The measured reach distances in this study matched previous values obtained using more expensive 3D motion analysis equipment.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
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 study only included healthy young men, so these error margins may not apply to elderly patients or those with neurological conditions like stroke or Parkinson's disease. Only one rater performed all the measurements, so it is unknown if different therapists would get the same results using this software. The measurements were taken in a controlled setting with markers on the body, which may not reflect how the software performs in a busy clinic with standard clothing.
Declared interests
The authors declared no conflict of interest.
The easy way to misread this
Do not assume the 18.3 mm error margin applies to your older or impaired patients. These values were derived from healthy young men with stable movements. In populations with balance issues or tremors, the measurement error could be significantly higher, making small changes harder to detect.