Sampling rate influences the regularity analysis of temporal domain measures of walking more than spatial domain measures.
Farahnaz Fallahtafti, Shane R Wurdeman, Jennifer M Yentes
PMID 34118746WHAT IT FOUND
Lowering camera sampling rates distorts time-based gait variability and regularity, making steps appear artificially periodic.
Spatial measures remain stable except at very low rates. Researchers should sample at ~120 Hz to ensure accurate gait analysis.
Key findings
01Step time variability and regularity were significantly altered by sampling rate, with lower rates creating artificially periodic signals.
02Step length variability was affected at the lowest rates (30 and 60 Hz), but regularity was not influenced by sampling rate.
03The authors recommend collecting gait kinematics at approximately 120 Hz to balance accuracy with processing time.
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 study used data from only 11 healthy young adults, so findings may not apply to populations with gait disorders or older adults. Data were collected during treadmill walking, which may differ from overground walking. Only one comfortable walking speed was analyzed; effects at other speeds are unknown. The study did not evaluate the impact of data filtering, which is commonly used in clinical gait analysis.
Declared interests
The authors have no conflicts of interest to disclose. The study was supported by the NIH and the U.S. Government.
The easy way to misread this
Do not assume that mean step length and step time are always safe to compare across studies with different sampling rates. While means were stable here, variability and regularity measures were significantly distorted by low sampling rates, so comparing these specific metrics across studies with different setups is invalid.