title: Three-dimensional kinematics of the scapula and trunk, and associated scapular muscle timing in individuals with stroke.
abstract: Poor scapulothoracic control is a risk for developing shoulder pathology, but has received little attention so far in individuals with stroke (IwS). Trunk and scapular kinematics and surface muscle activity were measured in 15 healthy controls and 18 IwS during a low and high forward flexion (FF). Group-differences in trunk and scapular kinematics were assessed during low and high FF using a t-test (independent samples). Differences in muscle onset and offset time relative to movement start (both FF tasks) were determined using a mixed model taking into account the different groups and muscles. Recruitment patterns per group and task were described based on significant differences between muscles. In IwS, earlier lower trapezius and late infraspinatus offset were found during low FF, as well as a later onset and earlier offset of serratus anterior. For low FF, significantly more trunk axial rotation was found in IwS during both elevation and lowering. During high FF, IwS showed significantly less scapular posterior tilt during elevation and more scapular lateral rotation during lowering. IwS demonstrated adaptive muscle timing with earlier initiation and late inactivation of lower trapezius and infraspinatus, possibly to compensate for a late activation and early deactivation of the serratus anterior and to establish as such the correct pattern of scapulothoracic movement.
authors.affiliation: REVAL Rehabilitation Research Center - BIOMED Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Agoralaan Building A, 3590 Diepenbeek, Belgium. Electronic address: Liesbet.debaets@uhasselt.be.
authors.forename: Liesbet
authors.initials: L
authors.lastname: De Baets
authors.affiliation: REVAL Rehabilitation Research Center - BIOMED Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Agoralaan Building A, 3590 Diepenbeek, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Van Deun
authors.affiliation: CMAL Clinical Motion Analysis Laboratory, University Hospital Pellenberg, Weligerveld 1, 3212 Pellenberg, Belgium.
authors.forename: Davide
authors.initials: D
authors.lastname: Monari
authors.affiliation: Neural Control of Movement Lab, ETH Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Ellen
authors.initials: E
authors.lastname: Jaspers
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D006801:Humans; D007596:Joints / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009068:Movement; D018482:Muscle, Skeletal / Q000503:physiopathology*; D016059:Range of Motion, Articular; D011999:Recruitment, Neurophysiological; D012399:Rotation; D012540:Scapula / Q000503:physiopathology*; D020521:Stroke / Q000503:physiopathology*; D060726:Torso / Q000503:physiopathology*
keywords: Kinematics; Muscle timing; Scapula; Stroke; Trunk