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Assessment of Local Dynamic Stability in Gait Based on Univariate and Multivariate Time Series.
- Source :
-
Computational and mathematical methods in medicine [Comput Math Methods Med] 2019 Jul 25; Vol. 2019, pp. 6917658. Date of Electronic Publication: 2019 Jul 25 (Print Publication: 2019). - Publication Year :
- 2019
-
Abstract
- The ability of the locomotor system to maintain continuous walking despite very small external or internal disturbances is called local dynamic stability (LDS). The importance of the LDS requires constantly working on different aspects of its assessment method which is based on the short-term largest Lyapunov exponent (LLE). A state space structure is a vital aspect of the LDS assessment because the algorithm of the LLE computation for experimental data requires a reconstruction of a state space trajectory. The gait kinematic data are usually one- or three-dimensional, which enables to construct a state space based on a uni- or multivariate time series. Furthermore, two variants of the short-term LLE are present in the literature which differ in length of a time span, over which the short-term LLE is computed. Both a state space structure and the consistency of the observations based on values of both short-term LLE variants were analyzed using time series representing the joint angles at ankle, knee, and hip joints. The short-term LLE was computed for individual joints in three state spaces constructed on the basis of either univariate or multivariate time series. Each state space revealed walkers' locally unstable behavior as well as its attenuation in the current stride. The corresponding conclusions made on the basis of both short-term LLE variants were consistent in ca. 59% of cases determined by a joint and a state space. Moreover, the authors present an algorithm for estimation of the embedding dimension in the case of a multivariate gait time series.<br />Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper.
- Subjects :
- Aged
Algorithms
Ankle Joint physiology
Biomechanical Phenomena
Exercise Test statistics & numerical data
Female
Gait Analysis statistics & numerical data
Hip Joint physiology
Humans
Knee Joint physiology
Male
Mathematical Concepts
Models, Biological
Multivariate Analysis
Systems Theory
Time Factors
Gait physiology
Gait Analysis methods
Walking physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1748-6718
- Volume :
- 2019
- Database :
- MEDLINE
- Journal :
- Computational and mathematical methods in medicine
- Publication Type :
- Academic Journal
- Accession number :
- 31428185
- Full Text :
- https://doi.org/10.1155/2019/6917658