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فهرست مقالات

The Plantar Pressure Distribution among Low Back Pain Patients in Static and Dynamic Positions

نویسنده:

(4 صفحه - از 263 تا 266)

خلاصه ماشینی:

"c om ISSN (Online): 2322 – 4479 Roundhouse Kick’s Variability in Kinematic Coupling Assessed by Continuous Relative Phase and Vector Coding in Elite Taekwondo Players 1Kamran Azma, 2Hamid Reza Barnamei∗ 1. In light of these differences, there is no assurance that vector coding and CRP convey similar information on the structure of variability when they are used to study a particular movement. com Issue were to directly compare roundhouse kick’s variability quantified by vector coding and CRP in Taekwondo, and to determine if these techniques convey similar information on variability. In experimental setup, we chose the roundhouse kick being testing movement, which is the most frequently used technique in competitions, the Motion Analysis System with 5 high speed cameras (S Infrared, Vicon camera, Oxford metrics, Oxford, UK) were used to collect the kinematics data (sampling rate at 200 Hz) through tracking the 22 makers automatically, and then the joint velocity and angular velocity for each lower limb were derived from the time series."

صفحه: از 263 تا 266
263 Annals of Applied Sport Science , Spring 2015, Volume 3 - Number 9

264 Annals of Applied Sport Science , Spring 2015, Volume 3 - Number 9

Issue

were to directly compare roundhouse kick’s variability quantified by vector coding and‌ CRP‌ in

Taekwondo, and to determine if these techniques convey similar information on variability‌.

METHODS‌

Six‌ elite athletes of National Taekwondo Team of Iran who won many medals of Taekwondo

games‌ at‌ international level. In experimental setup, we chose the roundhouse kick being testing‌ movement‌, which‌ is the most frequently used technique in competitions, the Motion Analysis System with 5 high speed‌ cameras‌ (S Infrared‌, Vicon camera, Oxford metrics, Oxford, UK) were used to collect the kinematics‌ data‌ (sampling rate at 200 Hz) through tracking the 22 makers automatically, and then the joint velocity‌ and‌ angular velocity for each lower limb were derived from the time series‌. The‌ movement time was calculated from toe-off‌ to‌ the‌ ground contact. In all the examples that‌ follow‌, the coupling between two time-varying signals and was assessed. The two signals‌ were‌ always of equal length, sampled‌ n times‌ at the‌ same‌ points‌ in time.

2.1. Vector coding

Vector coding‌ was‌ performed using the method of Sparrow et al. (1987). A phase plane was‌ constructed‌, consisting of on the x-axis and‌ on the y-axis. Coupling‌ between‌ and was quantified by the‌ coupling‌ angle between consecutive coordinates in the phase plane

Where i indicates the point within‌ the‌ time series.

2.2. Continuous relative phase‌

Continuous‌ relative‌ phase (CRP) was‌ performed‌ using the method of‌ Hamill‌ et al. (1999). The state of each signal was assumed to be described by‌ two‌ state variable and with amplitude A and‌ frequency‌ f

A phase plane‌ was‌ constructed‌ with on the x-axis‌ and on the y-axis.

Coupling was quantified by the CRP angle , which is the difference‌ between‌ the phase angles of two signals‌

Where‌ and‌ are‌ the‌ phase angles for‌ the‌ first and second signals, respectively.

RESULTS

In this paper, first calculate angle of lower limb joints‌ and‌ then‌ calculate the angular velocity of

them. With‌ sketch‌ the‌ angle‌-angle‌ and‌ angle- angular velocity diagram, analysis to be perfect. Figure1, show the angel-angular velocity diagram of Hip and Knee. Figure2, show the angle- angle diagram of Knee‌ and Hip.

265 Annals of Applied Sport Science , Spring 2015, Volume 3 - Number 9

266 Annals of Applied Sport Science , Spring 2015, Volume 3 - Number 9