Simple method to reduce the effect of patient positioning variation on three-dimensional motion analysis during treadmill gait.
Recently, three-dimensional (3D) closed curve trajectories of markers placed at strategic body locations, called cyclograms or Lissajous-like graphs, are used for treadmill gait analysis. A simple method is presented to reduce the effect of patient positioning variation. After breaking down movement into three components (anterior-posterior, medial-lateral and superior-inferior), the time-series data and time-inverted data are serially concatenated. A fast Fourier transform (FFT) is done, and a high-pass filter (except 0 Hz) is applied to the anterior-posterior and medial-lateral components. Next an inverse FFT is executed, and the posterior half of the outcome, corresponding to time-inverted data, is deleted. The 3D closed curve is then reconstructed. Results showed that the proposed method was able to reduce the effect of patient positioning variation. Since the adjusted curve is simply a symbolized gait pattern, the method might be useful as an adjunct tool in observational gait analysis.
Faculty of Rehabilitation, School of Health Sciences, Fujita Health University.
Shigeo
S
Tanabe
Department of Rehabilitation Medicine I, School of Medicine, Fujita Health University.
Eiichi
E
Saitoh
Faculty of Rehabilitation, School of Health Sciences, Fujita Health University.
Kei
K
Ohtsuka
Faculty of Rehabilitation, School of Health Sciences, Fujita Health University.
Toshio
T
Teranishi
Fujita Memorial Nanakuri Institute, Fujita Health University , Japan.
Yutaka
Y
Tomita
Faculty of Rehabilitation, School of Health Sciences, Fujita Health University.
Yoshihiro
Y
Muraoka
gait analysis; gait trajectory; treadmill