title: The Impact of Segmental Trunk Support on Posture and Reaching While Sitting in Healthy Adults.
abstract: The authors investigated postural and arm control in seated reaches while providing trunk support at midribs and pelvic levels in adults. Kinematics and electromyography of the arm and ipsiliateral and contralateral paraspinal muscles were examined before and during reaching. Kinematics remained constant across conditions, but changes were observed in neuromuscular control. With midribs support, the ipsilateral cervical muscle showed either increased anticipatory activity or earlier compensatory muscle responses, suggesting its major role in head stabilization. The baseline activity of bilateral lumbar muscles was enhanced with midribs support, whereas with pelvic support, the activation frequency of paraspinal muscles increased during reaching. The results suggest that segmental trunk support in healthy adults modulates ipsilateral or contralateral paraspinal activity while overall kinematic outputs remain invariant.
authors.affiliation: a Motor Control and Cognition Lab, Human Physiology Department & Institute of Neuroscience , University of Oregon , Eugene , Oregon.
authors.forename: Victor
authors.initials: V
authors.lastname: Santamaria
authors.affiliation: a Motor Control and Cognition Lab, Human Physiology Department & Institute of Neuroscience , University of Oregon , Eugene , Oregon.
authors.forename: Jaya
authors.initials: J
authors.lastname: Rachwani
authors.affiliation: a Motor Control and Cognition Lab, Human Physiology Department & Institute of Neuroscience , University of Oregon , Eugene , Oregon.
authors.forename: Wayne
authors.initials: W
authors.lastname: Manselle
authors.affiliation: b Department of Rehabilitation Sciences , University of Hartford , West Hartford , Connecticut.
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Saavedra
authors.affiliation: a Motor Control and Cognition Lab, Human Physiology Department & Institute of Neuroscience , University of Oregon , Eugene , Oregon.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Woollacott
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D004576:Electromyography; D005260:Female; D006801:Humans; D008161:Lumbosacral Region / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D000077708:Sitting Position; D060726:Torso / Q000502:physiology*; D055815:Young Adult
keywords: EMG; goal-directed action; kinematics; postural control