Quantitative and qualitative gait assessments in Parkinson's disease patients.

Introduction/Aim : Postural impairments and gait disorders in Parkinson's disease affect limits of stability, impaire postural adjustment, and evoke poor responses to perturbation. In the later stage of the disease, some patients can suffer from episodic features such as freezing of gait. Objective gait assessment and monitoring progress of the disease can give clinicians and therapist important information about changes in gait pattern and potential gait deviations, in order to prevent concomitant falls. Aim was to propose a method for identification of freezing episodes and gait disturbances for patients with PD. The wireless inertial sensor system can be used to provide follow-up of the treatment effects or progress of the disease. Method : The system is simple for mounting on a subject, comfortable, simple for installing and recording, reliable and provides high-quality sensor data. 12 patients were recorded and tested. Software calculates various gait parameters that could be estimated. User friendly visual tool provides information about changes in gait characteristics, either in a form of spectrogram or by observing spatio-temporal parameters. Based on these parameters, the algorithm performs classification of strides and identification of FOG types. Results : The described stride classification is merged with an algorithm for stride reconstruction, which resulted in useful graphical tool that allows clinicians to inspect and analyze subject’s movements. Conclusion : The described gait assessment system can be used for detection and categorization of gait disturbances by applying rule-based classification based on stride length, stride time, and frequency of the shank segment movements. The method provides valuable graphical interface which is easy to interpret and provides clinicians and therapists with valuable information regarding the temporal changes in gait.