Evidence map›Paper›PMID 41686388›Full record

ArticleAnnals of biomedical engineering2026

Hurst-Kolmogorov Process is a More Reliable and Statistically Powerful Alternative to Detrended Fluctuation Analysis for Estimating Hurst in Short Walking Trials.

Vasileios Mylonas, Tyler M Wiles, Seung Kyeom Kim, Nick Stergiou, Aaron D Likens

Abstract read
In one paragraph

Article in Annals of biomedical engineering, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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1citing papers in PubMed
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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Vasileios MylonasDepartment of Biomechanics, University of Nebraska at Omaha, 6001 Dodge St, Omaha, Nebraska, 68182, USA.ORCID http://orcid.org/0000-0001-8820-2800
Tyler M WilesDepartment of Biomechanics, University of Nebraska at Omaha, 6001 Dodge St, Omaha, Nebraska, 68182, USA.
Seung Kyeom KimDepartment of Biomechanics, University of Nebraska at Omaha, 6001 Dodge St, Omaha, Nebraska, 68182, USA.
Nick StergiouDepartment of Biomechanics, University of Nebraska at Omaha, 6001 Dodge St, Omaha, Nebraska, 68182, USA.
Aaron D LikensDepartment of Biomechanics, University of Nebraska at Omaha, 6001 Dodge St, Omaha, Nebraska, 68182, USA. alikens@unomaha.edu.

Funding

Visual control of locomotion in people with Parkinsons diseaseP20GM109090 · NIGMS · UNIVERSITY OF NEBRASKA OMAHA · PI STERGIOU, NIKOLAOS · 2014 to 2023
$20.5M
Tissue Analysis Core (TAC)P20GM152301 · NIGMS · UNIVERSITY OF NEBRASKA OMAHA · PI Yury Salkovskiy · 2024 to 2026
$8.8M
National Science Foundation 212491NIGMS NIH HHS P20GM109090NIGMS NIH HHS P20GM152301
6 · The paper itself

Abstract

backgroundFor decades, researchers have used Detrended Fluctuation Analysis (DFA) as a method to assess the temporal structure of gait variability through the Hurst exponent (H). However, DFA's reliance on long time series limits reliability and reduces statistical power when applied to short walking trials, restricting its applicability. The Hurst-Kolmogorov process (HKp), an increasingly common algorithm, may offer more reliable and efficient estimates of the H in short walking trials. This study evaluated the reliability and statistical power of HKp versus DFA in estimating H from gait kinematics using short time series.

methods119 healthy adults (34 young, 57 middle-aged, and 38 older) were sampled from the NONAN GaitPrint dataset. Each participant walked 9 four-minute trials per day over the course of two days, which were a week apart. H was estimated for stride interval, stride length, and the lower limb joint range of motion using DFA and HKp. Kinematic variables were calculated for time series ranging from 50 to 175 strides. Intraclass correlation coefficients (ICCs) were calculated between days using the average of 1 to 9 trials per day. Power estimations using simulated time series were performed to assess the ability of each method to detect group differences under varying effect sizes, sample sizes, trial numbers, and time series lengths.

resultsHKp achieved excellent reliability (ICC > 0.90) in short trials (<100 strides), whereas DFA rarely exceeded moderate reliability. Statistical power simulations demonstrated that HKp yielded higher power than DFA, particularly when fewer trials and subjects were available. A summary table is provided to guide sample size selection under different design conditions.

conclusionHKp offers a more reliable and statistically powerful alternative to DFA for estimating H in short walking trials. These findings support HKp as a practical tool for assessing the temporal structure of gait variability, improving feasibility in experimental and research settings.

Indexed as

AlgorithmsGaitWalkingAdultAgedBiomechanical PhenomenaFemaleHumansMaleMiddle AgedReproducibility of ResultsYoung AdultFractal analysisGait variabilityIntraclass correlation coefficientNonlinear analysisPower analysis

Identifiers

PMID41686388
PMCPMC13186840

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