Upper body accelerations as a biomarker of gait impairment in the early stages of Parkinson's disease

• Main Author: Buckley, Christopher
• Other Authors: Mazzà, Claudia ; Rochester, Lynn ; Galna, Brook
• Published: University of Sheffield 2017
• Subjects: 621
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.736565

Neurodegenerative diseases such as Parkinson's disease (PD) impair the ability to walk safely and efficiently. Currently, clinical rating scales designed to assess gait are often described to be subjective and lacking sensitivity to detect gait impairments at the early stage of the disease. Devices are available to objectively measure gait within research laboratories; however, they are often expensive and require trained expertise. Inertial measurement units (IMUs) may be an ideal device to measure gait while overcoming many of the limitations of other devices. They can measure movements of the upper body, which in PD is known to be impaired, and therefore may enable the calculation of a variety of acceleration based variables better capable to quantify impaired gait in PD. This thesis aimed to determine the ability of a variety of acceleration based variables obtained from different location of the upper body to detect movements symptomatic to PD from age matched controls. Variables yet to be applied to PD were tested and methodological reasons for why differing results found in the literature was analysed, in an attempt to develop a refined methodology specific to PD. Acceleration based variables were tested relative to, and combined with, variables obtained from a 7m pressure sensitive mat. It was tested whether these variables bring additional information about a patient's gait or if they are merely a reflection of lower limb mechanics, and, whether they can classify PD gait independently or in combination with a pre-existing spatiotemporal model of gait. Results showed that for a large population of people with early stage PD, upper body acceleration variables not previously applied to PD were capable to highlight gait impairments. However, attention must be made to the processing of the acceleration signals as the method used to realign signals to a global reference can significantly impact a variable's sensitivity to PD. Lastly, it was shown that the majority of upper body acceleration variables are unique from typically measured spatiotemporal information, and when using a multivariate approach, were equally capable to highlight gait impairment in PD. This thesis therefore proposes that variables calculated from the upper body using IMUs can be useful biomarkers of gait impairment at the early stage of PD, and if possible, should be used in conjunction with traditional approaches.