Gait analysis in frequency domain for freezing detection in patients with Parkinson’s disease

of gait (FOG) is a common and disabling symptom of Parkinson's disease. It is an episodic and non predictable phenomenon that affects most commonly the gait in the form of start hesitation and sudden immobility. It often results in falls and consequent injuries reducing quality of life. In this pilot study sensors measuring acceleration in 3 axes and angular velocity in 2 axes have been used to monitor foot, shank and thigh movements. Also the magnitude of acceleration was calculated for each 3-axis accelerometer. To determine changes in the power spectral density (PSD) the short time Fourier transform (STFT) was used. The results showed significant shift of the PSD towards higher frequencies during FOG episodes (p=0.00002) in vertical linear acceleration and in the angular velocity of the heel (p=0.00003). 82,7 % of the FOG episodes were detected correctly using motion parameters obtained from the acceleration perpendicular to the coronal plane of the heel.