Assessment of Postural Instability in Patients With a Neurological Disorder Using a Tri-Axial Accelerometer

Abstract

Abstract. Current techniques for quantifying human postural stability during quiet standing have several limitations. The main problem is that only two movement variables are evaluated, though a better description of complex three-dimensional (3-D) movements can be provided with the use of three variables. A single tri-axial accelerometer placed on the trunk was used to measure 3-D data. We are able to evaluate 3-D movements using a method based on the volume of confidence ellipsoid (VE) of the set of points obtained by plotting three accelerations against each other. Our method was used to identify and evaluate pathological balance control. In this study, measurements were made of patients with progressive cerebellar ataxia, and also control measurements of healthy subjects, and a statistical analysis was performed. The results show that the VEs of the neurological disorder patients are significantly larger than the VEs of the healthy subjects. It can be seen that the quantitative method based on VE is very sensitive for identifying changes in stability, and that it is able to distinguish between neurological disorder patients and healthy subjects.

Analyzing the Use of Accelerometers as a Method of Early Diagnosis of Alterations in Balance in Elderly People: A Systematic Review

“…Data have even been obtained that show greater sensitivity to the accelerometers in front of the force platforms [84]. The accelerometric evaluation of the balance has been compared repeatedly with the results in clinical trials and tests, with positive results in different populations, such as elderly people with a history of falls [93,94] or a cerebrovascular accident [94], children with dyslexia [95], patients with Huntington’s [96], with Parkinson’s disease [47], with progressive cerebellar ataxia [97], and with vestibular disorders [98].…”

Postural control deficit during sit-to-walk in patients with Parkinson’s disease and freezing of gait

“…The second analysis is focused to describe the peculiar behaviour of each group in the three tasks. To explicitly analyse postural control differences between participants, we considered the three-dimensional data of COP and COM positions and compared the volumes of prediction ellipsoid [25][26][27][28][29] of each group by means of the Generalized Variance (GV), a scalar measure of dispersion defined as the determinant of the sample covariance matrix and proportional to specific equal- probability contour (i.e., standard ellipsoid) of the measured data. Between groups inferential tests were conducted on GVs with a Chi-square log-Likelihood Ratio Test [30,31].…”

Postural Stability Evaluation of Patients Undergoing Vestibular Schwannoma Microsurgery Employing the Inertial Measurement Unit

“…The research conducted and this follow-up study on postural instability in patients with VS using an IMU placed on the patient's trunk and the Leibniz method show that the method presented is suitable for the identification of postural balance problems. This technique described allows for the study of three measured variables (three angles and three accelerations) of 3-D body movement [ 41 , 42 ]. Adopting this approach overcomes the greatest limitation of traditional methods relying on just two variables, each in one of the two human body axes of the transverse level (as used in CoP research) [ 41 , 42 ].…”

“…This technique described allows for the study of three measured variables (three angles and three accelerations) of 3-D body movement [ 41 , 42 ]. Adopting this approach overcomes the greatest limitation of traditional methods relying on just two variables, each in one of the two human body axes of the transverse level (as used in CoP research) [ 41 , 42 ]. Although this new technique has never been used for the study of patients with VS, its application can be found in other fields, for data analysis obtained by an IMU in cell phones or electronic watches.…”

“…Although this new technique has never been used for the study of patients with VS, its application can be found in other fields, for data analysis obtained by an IMU in cell phones or electronic watches. This new technological application can lead to greater use of the proposed methods in small health clinics or even at home [ 41 , 42 ].…”