Power spectrum and filtering

This chapter introduces spectral and frequency-domain analysis methods for gait and movement biomechanics data. Topics covered include the properties of a composite wave, spectral analysis, Fourier series and the discrete Fourier transform, stationarity, the short-time discrete Fourier transform, sources of noise in kinematic and kinetic signals, and data filtering. The chapter closes with practical guidance for implementing spectral analysis and filtering techniques in biomechanical data.