The proposed method serves for detecting and analysing translating and non-translating periodic motion with small oscillation from video data. Periodic motion in a video sequence is detected using principles of motion accumulation. Non-translating periodic motion is described as change of the point brightness over the time. The trajectory of the motion is obtained by tracking the translating object with periodic motion. Following frequency analysis is done by the means of Fourier transform. The developed method is applied for observing patients suffering from Parkinson disease.