Quaternions and joint angles in an analysis of local stability of gait for different variants of walking speed and treadmill slope

Pirek, Micha; Josiski, Henryk; Michalczuk, Agnieszka; witoski, Adam; Szczsna, Agnieszka

doi:10.1016/j.ins.2016.08.069

Cited by 27 publications

(16 citation statements)

References 35 publications

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“…Movements of all considered body parts and experiments configurations are characterized by the positive value of entropy, which detect and quantify chaotic behavior. This is consistent with results obtained with use of

in [ 22 ], for which all times series are characterized by positive values of

. The median values for all segments are also presented in Table 1 .…”

Section: Resultssupporting

confidence: 92%

“…In [ 22 ], the authors describe an example of application of a nonlinear time series analysis directed at identifying the presence of deterministic chaos in human gait kinematic data by means of the largest Lyapunov exponent (

). A positive

value is interpreted as an indicator of local instability.…”

Section: Methodsmentioning

confidence: 99%

“…Mean values of a stride interval for every variant are 1.20 s for Normal speed (standard deviation 0.15), 1.40 m/s for Slower speed (standard deviation 0.21), 1.13 m/s for Faster speed (standard deviation 0.14), 1.27 m/s for Slope-up (standard deviation 0.18) and 1.24 m/s for Slope-down (standard deviation 0.16). This same dataset was also used in [ 22 , 31 ].…”

Section: Methodsmentioning

confidence: 99%

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Quaternion Entropy for Analysis of Gait Data

Szczęsna

2019

Entropy

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Nonlinear dynamical analysis is a powerful approach to understanding biological systems. One of the most used metrics of system complexities is the Kolmogorov entropy. Long input signals without noise are required for the calculation, which are very hard to obtain in real situations. Techniques allowing the estimation of entropy directly from time signals are statistics like approximate and sample entropy. Based on that, the new measurement for quaternion signal is introduced. This work presents an example of application of a nonlinear time series analysis by using the new quaternion, approximate entropy to analyse human gait kinematic data. The quaternion entropy was applied to analyse the quaternion signal which represents the segments orientations in time during the human gait. The research was aimed at the assessment of the influence of both walking speed and ground slope on the gait control during treadmill walking. Gait data was obtained by the optical motion capture system.

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in [ 22 ], for which all times series are characterized by positive values of

. The median values for all segments are also presented in Table 1 .…”

Section: Resultssupporting

confidence: 92%

). A positive

value is interpreted as an indicator of local instability.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Quaternion Entropy for Analysis of Gait Data

Szczęsna

2019

Entropy

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“…Gait stability is usually evaluated by dynamic stability because gait is a dynamic movement. Dynamic stability can be divided into local dynamic stability and global dynamic stability depending on small and large perturbations respectively from internal and external sources [ 15 , 16 , 19 ]. Bruijn et al [ 15 ] assessed four levels of validity of common gait stability measures and found that measures with high validity included largest Lyapunov exponent and variability measures in local dynamic stability, and foot placement estimator and margin of stability in global dynamic stability.…”

Section: Introductionmentioning

confidence: 99%

Dynamic stability and spatiotemporal parameters during turning in healthy young adults

Zhao

et al. 2018

BioMed Eng OnLine

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Background and purposeTurning while walking has a frequent occurrence in daily life. Evaluation of its dynamic stability will facilitate fall prevention and rehabilitation scheme. This knowledge is so limited that we set it as the first aim of this study. Another aim was to investigate spatiotemporal parameters during turning.MethodsFifteen healthy young adults were instructed to perform straight walking, 45° step turn to the left and 45° spin turn to the right at natural speed. Dynamic stability was measured by margin of stability (MoS) in anterior, posterior, left and right direction at each data point where significant differences were detected using 95% bootstrap confidence band. Common spatiotemporal parameters were computed in each condition subdivided into approach, turn and depart phases.ResultsResults showed that minimum anterior MoS appeared at middle of swing while minimum lateral MoS at contralateral heel strike in all conditions. Posterior MoS decreased before middle of turn phase in spin whereas after middle of turn phase in step. Lateral MoS and stride width declined in turn phase of spin while in depart of step. Spin had a long step and stride length. Long swing phases were observed in turns.ConclusionsThese data help explain that people are most likely to fall forward at middle of swing and to fall toward the back and the support side at heel strike. Our findings demonstrate that instability mainly exist in turn phase of spin and depart phase of step turn.Electronic supplementary materialThe online version of this article (10.1186/s12938-018-0558-5) contains supplementary material, which is available to authorized users.

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“…The main influencing factors of the stable gait were discussed and the steps from starting to walking steadily State adjustment mode, planning a steady cycle of gait. Piórek et al [13] described an example of application of a nonlinear time series. The research aimed at assessment of the influence of both walking speed and ground slope on the resilience of gait control to infinitesimally small perturbations that occur naturally during walking.…”

Section: Introductionmentioning

confidence: 99%

Development of agricultural bionic mechanisms: investigation of the effect of joint angle and pressure on the stability of goats moving on sloping lands

Zhang

Li-min

Wang

et al. 2018

International Journal of Agricultural and Biological Engineering

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Abstract:The use of small-scale agricultural machinery becomes prevalent as it provides the stability of agricultural machinery research ideas. To lay the theoretical foundation for the research and design of agriculture walking mechanism, the Phantom Camera Control software was used to measure the anterior and posterior joint angle of a goat walking on different slopes. Foot pressure was measured by the film pressure sensor. The result of joint motion sequence, range of motion, and change of range showed that the fitting degree of the measured value was accurate. As the goat walking speed increased, the level of the hind limb angle changed to ensure itself stability. When the goat is walking, the forelimbs bear more weight than the hind limbs due to the different static and physiological structures of the front and rear legs. The key parameters of gait on different slopes were analyzed. The curve of angle change of legs was measured and analyzed when the goat is walking in slope. The results showed that, with the increase of the slope gradient, the anterior hip angle ranges from 83.3° to 117.1°, the posterior hip angle ranges at 120.3°-173.1°, the left knee angle ranges from 91.3° to 170.1°, the right knee angle is roughly the same as its range of variation. When the slope increased, the pressure change of left hind foot was consistent with that of the right anterior foot, and the pressure change of right hind foot was consistent with that of the left anterior foot. This demonstrated the theory of diagonal gait. Meanwhile, with the change of the slope, the plantar pressure of the limbs changes periodically. The research results verified the rationality of the four-legged bionic mechanism under various parameters, which can provide a theoretical basis for the design of agricultural walking mechanism to adapt different slopes in the hilly and mountainous areas.

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Quaternions and joint angles in an analysis of local stability of gait for different variants of walking speed and treadmill slope

Cited by 27 publications

References 35 publications

Quaternion Entropy for Analysis of Gait Data

Quaternion Entropy for Analysis of Gait Data

Dynamic stability and spatiotemporal parameters during turning in healthy young adults

Development of agricultural bionic mechanisms: investigation of the effect of joint angle and pressure on the stability of goats moving on sloping lands

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