EFFECT OF WINDOW LENGTH WHEN SMOOTHING WITH SINGULAR SPECTRUM ANALYSIS TECHNIQUE IN RUNNING DATA

Authors

  • Kazuhiro Ishimura
  • Shinji Sakurai

Keywords:

smoothing, SSA, running kinematics filter, optimum cutoff frequency

Abstract

The purpose of this study was to demonstrate the effect of window length on running kinematic data in comparison to data smoothed using a digital Butterworth low pass filter. The raw marker trajectories were smoothed using a digital Butterworth filter with an optimum cutoff frequency and using the SSA technique with window lengths of L = n/2, n/5, and n/10 (n = 220). Data smoothing using SSA parameters of L = n/10, r = 2 produced similar results to the Butterworth low pass filter with an optimal cutoff frequency of 13 Hz. In conclusion, a window length of L = n/10 is recommended for running kinematics research, while window lengths of L = n/2 should be avoided.

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Issue

30 International Conference on Biomechanics in Sports (2012)

Section

Coaching and Sports Activities

License

Authors can retain copyright, while granting the International Society of Biomechanics in Sports (ISBS) the right of first publication.