Accuracy and repeatability of smartphone sensors for measuring shank-to-vertical angle.
Brandon T Nguyen, Nick A Baicoianu, Darrin B Howell and 2 others
PMID 32312145WHAT IT FOUND
A smartphone on the front of the shin measured shank angle during walking 0.67° from the marker-based angle on average, but side placement was less accurate and repeatable.
Only two healthy adults were tested.
Key findings
01Compared with marker-based motion capture, the phone angle was on average 0.67 ± 0.25° away from the motion-capture angle when placed on the front of the shin, and 4.89 ± 0.72° away when placed on the side.
02Between clinicians, phone measurements differed by 0.72 ± 0.31° for front placement and 1.16 ± 0.28° for side placement.
03The phone consistently reported a higher shank angle than motion capture for front placement and a lower shank angle for side placement.
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
Only two unimpaired adults were tested, so the results do not show accuracy or repeatability in children or people with abnormal gait. The four clinicians were highly experienced, with 23 to 43 years of experience, so new clinicians may need training to get similar results. Clinicians had no practice or training using the smartphone before testing, and instructions were not strict beyond tight attachment and landmark alignment. The phone was attached with an elastic running armband, could shift during walking, and proximal or distal placement was not specified. The front and side positions are not equivalent because of tibial shape, and individual differences in tibial structure are not well documented. The study did not test devices, children, or patients with abnormal gait, and it did not measure treatment outcomes.
Declared interests
The supplied text does not state funding or conflicts of interest.
The easy way to misread this
Do not conclude that a smartphone can replace marker-based gait analysis for patient care. It was tested in only two healthy adults by experienced clinicians, and side placement had much larger error than front placement.