Failure of Arm Movement Control in Stroke Patients, Characterized by Loss of Complexity

Segun Goh; Kyungreem Han; Jehkwang Ryu; Seonjin Kim; MooYoung Choi

doi:10.1371/journal.pone.0141996

Failure of Arm Movement Control in Stroke Patients, Characterized by Loss of Complexity

PLoS One. 2015 Nov 4;10(11):e0141996. doi: 10.1371/journal.pone.0141996. eCollection 2015.

Authors

Segun Goh¹, Kyungreem Han¹, Jehkwang Ryu², Seonjin Kim³, MooYoung Choi¹

Affiliations

¹ Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747, Korea.
² Institute for Cognitive Science, College of Humanities, Seoul National University, Seoul 151-742, Korea.
³ Department of Physical Education, Seoul National University, Seoul 151-748, Korea.

Abstract

We study the mechanism of human arm-posture control by means of nonlinear dynamics and quantitative time series analysis methods. Utilizing linear and nonlinear measures in combination, we find that pathological tremors emerge in patient dynamics and serve as a main feature discriminating between normal and patient groups. The deterministic structure accompanied with loss of complexity inherent in the tremor dynamics is also revealed. To probe the underlying mechanism of the arm-posture dynamics, we further analyze the coupling patterns between joints and components, and discuss their roles in breaking of the organization structure. As a result, we elucidate the mechanisms in the arm-posture dynamics of normal subjects responding to the gravitational force and for the reduction of the dynamic degrees of freedom in the patient dynamics. This study provides an integrated framework for the origin of the loss of complexity in the dynamics of patients as well as the coupling structure in the arm-posture dynamics.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Algorithms
Arm / physiopathology*
Biomechanical Phenomena
Case-Control Studies
Humans
Movement
Posture
Stroke / physiopathology*

Grants and funding

This work was supported by the National Research Foundation of Korea, through grants 2012R1A2A4A01004419 and 2011-0012331 (MYC), 2014R1A6A3A01059467 (SG), and 2010-0021103 (SK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.