Nonlinear analysis reveals duration and gradient-dependent disruption of load carriage gait variability during an outdoor 6.72 km time trial in military personnel
Evan D. Feigel , Ayden McCarthy , Joel T. Fuller , Lily Rosenblum , Mita Lovalekar , Tommi Ojanen , Kai Pihlainen , Brian J. Martin , Kristen J. Koltun , Tim L.A. Doyle , Bradley C. Nindl
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引用次数: 0
Abstract
This investigation assessed the effect of gradient and duration on the gait variability exponent, DFA-α, in military personnel affixed with dual inertial measurement units performing a load carriage time-trial. Gait data (N = 14) were partitioned into 256 stride time segments by gradient (uphill, downhill) using a gait event algorithm. Detrended fluctuation analysis calculated DFA-α per segment, which was averaged across one-third durations (phases 1–3) per gradient. Two-way repeated measures ANOVA examined effects of gradient, duration, and interaction on DFA-α, with Bonferroni-adjusted post-hoc comparisons. There was a significant main effect of duration (phase 1: 0.593 ± 0.021; phase 2: 0.563 ± 0.031; phase 3: 0.493 ± 0.021; F = 3.833, p = 0.035, ηp2 = 0.228), but not gradient (uphill: 0.486 ± 0.031; downhill: 0.614 ± 0.035; F = 4.252, p = 0.060, ηp2 = 0.246), or interaction (F = 0.019, p = 0.981, ηp2 = 0.001). Pairwise comparisons revealed significantly lower DFA-α during phase 3 than phase 1 (p = 0.016). Elapsed duration and uphill gradient, despite a large, but non-significant effect, may represent factors altering gait variability for injury risk.
期刊介绍:
Applied Ergonomics is aimed at ergonomists and all those interested in applying ergonomics/human factors in the design, planning and management of technical and social systems at work or leisure. Readership is truly international with subscribers in over 50 countries. Professionals for whom Applied Ergonomics is of interest include: ergonomists, designers, industrial engineers, health and safety specialists, systems engineers, design engineers, organizational psychologists, occupational health specialists and human-computer interaction specialists.