PMID- 20129787
OWN - NLM
STAT- MEDLINE
DCOM- 20100610
LR  - 20220317
IS  - 1879-2219 (Electronic)
IS  - 0966-6362 (Linking)
VI  - 31
IP  - 3
DP  - 2010 Mar
TI  - Non-linear analysis of the structure of variability in midfoot kinematics.
PG  - 385-90
LID - 10.1016/j.gaitpost.2010.01.008 [doi]
AB  - INTRODUCTION: Evaluation of structural variability in biological time series 
      through measures such as sample entropy (SaEn) has provided important information 
      in neurology and cardiology. This has contributed to the development of the "loss 
      of complexity hypothesis" where high variability has been described as healthy 
      flexibility and low variability associated with pathology. The purpose of this 
      study was to calculate sample entropy (SaEn) to establish normal values of 
      non-linear variability and to examine which factors are associated with SaEn in 
      midfoot kinematics. METHOD: Static foot posture was measured using Foot Posture 
      Index. A video sequence analysis system was used to quantify midfoot kinematics 
      during walking in the sagittal plane. SaEn was calculated for navicular drop 
      during stand phase as an expression of the dynamic complexity. RESULTS: A 
      significant difference was observed between the three major foot types and 
      between genders (p<0.001). Mean SaEn in women were 1.10+/-0.19 (supinated foot 
      posture), 0.96+/-0.17 (neutral foot posture) and 0.77+/-0.16 (pronated foot 
      posture) and 1.25+/-0.24 (supinated foot posture), 1.06+/-0.23 (neutral foot 
      posture) and 0.86+/-0.19 (pronated foot posture) in males. The regression model 
      showed that foot posture and dynamic navicular drop (dND) were both associated 
      with SaEn. CONCLUSION: This study confirmed that non-linear analysis is of 
      relevance in the interpretation of kinematic data. Pronated foot posture, large 
      navicular drop and women were characterized by low values of non-linear 
      variability. Future studies should investigate if measurements of SaEn are 
      capable of identifying subjects with an increased risk of injury.
CI  - Copyright 2010 Elsevier B.V. All rights reserved.
FAU - Rathleff, M S
AU  - Rathleff MS
AD  - Orthopaedic Division, North Denmark Region, Aalborg Hospital-Aarhus University 
      Hospital, Aalborg, Denmark. michaelrathleff@gmail.com
FAU - Olesen, C G
AU  - Olesen CG
FAU - Moelgaard, C M
AU  - Moelgaard CM
FAU - Jensen, K
AU  - Jensen K
FAU - Madeleine, P
AU  - Madeleine P
FAU - Olesen, J L
AU  - Olesen JL
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100202
PL  - England
TA  - Gait Posture
JT  - Gait & posture
JID - 9416830
SB  - IM
MH  - Analysis of Variance
MH  - Anthropometry
MH  - Biomechanical Phenomena
MH  - Entropy
MH  - Female
MH  - Foot/*physiology
MH  - Humans
MH  - Male
MH  - Posture/*physiology
MH  - Pronation
MH  - Regression Analysis
MH  - Signal Processing, Computer-Assisted
MH  - Supination
MH  - Video Recording
MH  - Walking/*physiology
EDAT- 2010/02/05 06:00
MHDA- 2010/06/11 06:00
CRDT- 2010/02/05 06:00
PHST- 2009/08/29 00:00 [received]
PHST- 2010/01/07 00:00 [revised]
PHST- 2010/01/11 00:00 [accepted]
PHST- 2010/02/05 06:00 [entrez]
PHST- 2010/02/05 06:00 [pubmed]
PHST- 2010/06/11 06:00 [medline]
AID - S0966-6362(10)00009-3 [pii]
AID - 10.1016/j.gaitpost.2010.01.008 [doi]
PST - ppublish
SO  - Gait Posture. 2010 Mar;31(3):385-90. doi: 10.1016/j.gaitpost.2010.01.008. Epub 
      2010 Feb 2.