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1.1 1 xml info:srw/schema/1/mods-v3.2 Davidowitz I author Parmet Y author Frenkel-Toledo S author Banina M C author Soroker N author Solomon J M author Liebermann D G author Levin M F author Berman S author 2019 English BACKGROUND: Spasticity is common in patients with stroke, yet current quantification methods are insufficient for determining the relationship between spasticity and voluntary movement deficits. This is partly a result of the effects of spasticity on spatiotemporal characteristics of movement and the variability of voluntary movement. These can be captured by Gaussian mixture models (GMMs). OBJECTIVES: To determine the influence of spasticity on upper-limb voluntary motion, as assessed by the bidirectional Kullback-Liebler divergence (BKLD) between motion GMMs. METHODS: A total of 16 individuals with subacute stroke and 13 healthy aged-equivalent controls reached to grasp 4 targets (near-center, contralateral, far-center, and ipsilateral). Two-dimensional GMMs (angle and time) were estimated for elbow extension motion. BKLD was computed for each individual and target, within the control group and between the control and stroke groups. Movement time, final elbow angle, average elbow velocity, and velocity smoothness were computed. RESULTS: Between-group BKLDs were much larger than within control-group BKLDs. Between-group BKLDs for the near-center target were lower than those for the far-center and contralateral targets, but similar to that for the ipsilateral target. For those with stroke, the final angle was lower for the near-center target, and the average velocity was higher. Velocity smoothness was lower for the near-center than for the ipsilateral target. Elbow flexor and extensor passive muscle resistance (Modified Ashworth Scale) strongly explained BKLD values. CONCLUSIONS: Results support the view that individuals with poststroke spasticity have a velocity-dependent reduction in active elbow joint range and that BKLD can be used as an objective measure of the effects of spasticity on reaching kinematics. Gaussian mixture model Kullback-Liebler divergence spasticity stroke upper-limb kinematics PMID:30744528 exported from refbase (https://refbase.nfshost.com/show.php?record=93), last updated on Tue, 19 Feb 2019 14:09:03 +0000 text http://www.ncbi.nlm.nih.gov/pubmed/30744528 http://www.ncbi.nlm.nih.gov/pubmed/30744528 10.1177/1545968319826050 30744528 Davidowitz_etal2019 2019 continuing periodical academic journal 33 2 141 152 1545-9683 1