Movement variability in stroke patients and controls performing two upper limb functional tasks: a new assessment methodology

Abstract

Background: In the evaluation of upper limb impairment post stroke there remains a gap between detailed kinematic analyses with expensive motion capturing systems and common clinical assessment tests. In particular, although many clinical tests evaluate the performance of functional tasks, metrics to characterise upper limb kinematics are generally not applicable to such tasks and very limited in scope. This paper reports on a novel, user-friendly methodology that allows for the assessment of both signal magnitude and timing variability in upper limb movement trajectories during functional task performance. In order to demonstrate the technique, we report on a study in which the variability in timing and signal magnitude of data collected during the performance of two functional tasks is compared between a group of subjects with stroke and a group of individually matched control subjects.

Contribution of execution noise to arm movement variability in three-dimensional space

“…Execution noise also arises from both peripheral and central mechanisms and can have profound effects on movement variability (Buneo et al 1995;van Beers et al 2004). Understanding how planning-and execution-related noise interact is critical not only for explaining movement variability that is observed in neurologically intact human subjects but also for comprehending the exaggerated variability that arises following nervous system damage (Contreras-Vidal and Buch 2003;Hermsdorfer and Goldenberg 2002;Longstaff and Heath 2006;Thies et al 2009). In addition, the effects of this interaction are relevant to understanding such diverse sensorimotor functions as position estimation (van Beers et al 1998(van Beers et al , 1999(van Beers et al , 2002b, cue integration (Kording and Wolpert 2004), and motor adaptation (van Beers 2009).…”

Quantitative assessment based on kinematic measures of functional impairments during upper extremity movements: A review

“…Applied to reaching movements, the theoretical trajectory has been the straight line between start and end points. Moreover the spatial deviation, the time variability of the trajectory was analyzed in the study performed by Thies et al (2009)…”

Movement variability resulting from different noise sources: A simulation study

“…For example, noise associated with sensing the position of the limbs as well as noise occurring during the planning and execution of motor acts results in movement variability, a hallmark of human motor performance. In many neurological diseases this variability can be magnified (Contreras-Vidal & Buch, 2003;Hermsdorfer & Goldenberg, 2002;Longstaff & Heath, 2006;Thies et al, 2009), which can affect the performance of even simple motor acts. Thus, understanding the consequences of noise occurring at different stages of movement production can lead not only to a better understanding of neural processing but may also lead to better treatment approaches for some neurological disorders.…”