A Standardized Method of Detecting Movement Onset in Ballistic Wrist Extension Movements of Stroke Patients Restricted; Files Only

Gadipudi, Anusha (Spring 2021)

Permanent URL: https://etd.library.emory.edu/concern/etds/qz20st71r?locale=en


Ischemic stroke affecting the primary motor cortex (M1), or its corticospinal projections (CST) has been shown to impact hand function in humans and non-human primates. Considering the prevalence of ischemic stroke, it is essential to accurately quantify hand function in order to track post-stroke recovery of movement and guide rehabilitation. The experimental use of kinematic measures of hand movement - including the onset of the movement, peak velocity, and time to peak velocity – has grown rapidly over the past two decades as a method of quantifying behavioral restitution rather than compensation. The purpose of this study is to test the feasibility of a standardized method for determining the onset of movement in ballistic wrist extensions of patients recovering from ischemic stroke in M1 or CST. Currently the onset of movement is determined visual inspection. However, it is subject to a degree of inter-observer variability and may be time consuming and inefficient to use. Here we employed four methods of estimating the onset of movement– the visual inspection method, and three automated approaches, the sigma factor method, the 5% Max method, and the 10% Max method. The degree of a participant’s affectedness was quantified by their scores on the Jebsen-Taylor Hand Function Test (JTHFT). The visually determined onset was treated as the golden standard of determining the onset of movement. The onset time from the sigma factor method was found to be closest to the onset times from the visual inspection method, and therefore, the most accurate to the true onset. In participants with higher normalized JTHFT scores, the 10% Max method was less accurate to the true onset, and the 5% Max method of determining onset was generally the farthest from the true onset. Furthermore, a negative correlation was established between normalized JTHFT scores and the peak velocity of the ballistic wrist extensions, potentially explaining the failure of the 5% and 10% Max automated methods in participants with more affected hand function. These results indicate that the sigma factor method may have the most merit for use as a standard metric for determining the onset of ballistic wrist extension movements in individuals affected by ischemic stroke

Table of Contents

Introduction 0 1

Methods 03

Motor Tasks 05

Analysis 06

Visual Inspection 06

% Max 07

Sigma Factor 08

Unclear Onset 1 1

EMG Method 1 1

Jebsen -Taylor Hand Function Test 14

Results 16

The range of sigma factors that indicated the true onset 16

Movement onset determined by different approaches 17

Relationship between peak velocity and JTHFT 19

Relationship between JTHFT and Time Difference 2 0

Discussion 2 1

References 23

Figures and Tables

Table 1 04

Figure 1 06

Figure 2 07

Figure 3 08

Figure 4 09

Figure 5 10

Figure 6 10

Figure 7 1 2

Figure 8 1 3

Figure 9 13

Figure 10 1 4

Figure 11 16

Figure 12 17

Figure 13 18

Figure 14 18

Figure 15 19

Figure 16 2 0

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