title: Concussion is associated with altered preparatory postural adjustments during gait initiation.
abstract: Gait initiation is a useful surrogate measure of supraspinal motor control mechanisms but has never been evaluated in a cohort following concussion. The aim of this study was to quantify the preparatory postural adjustments (PPAs) of gait initiation (GI) in fifteen concussion patients (4 females, 11 males) in comparison to a group of fifteen age- and sex-matched controls. All participants completed variants of the GI task where their dominant and non-dominant limbs as the 'stepping' and 'support' limbs. Task performance was quantified using the centre of pressure (COP) trajectory of each foot (computed from a force plate) and a surrogate of the centre of mass (COM) trajectory (estimated from an inertial measurement unit placed on the sacrum). Concussed patients exhibited decreased COP excursion on their dominant foot, both when it was the stepping limb (sagittal plane: 9.71mm [95% CI: 8.14-11.27mm] vs 14.9mm [95% CI: 12.31-17.49mm]; frontal plane: 36.95mm [95% CI: 30.87-43.03mm] vs 54.24mm [95% CI: 46.99-61.50mm]) and when it was the support limb (sagittal plane: 10.43mm [95% CI: 8.73-12.13mm] vs 18.13mm [95% CI: 14.92-21.35mm]; frontal plane: 66.51mm [95% CI: 60.45-72.57mm] vs 88.43mm [95% CI: 78.53-98.32mm]). This was reflected in the trajectory of the COM, wherein concussion patients exhibited lower posterior displacement (19.67mm [95% CI: 19.65mm-19.7mm]) compared with controls (23.62mm [95% CI: 23.6-23.64]). On this basis, we conclude that individuals with concussion display deficits during a GI task which are potentially indicative of supraspinal impairments in motor control.
authors.affiliation: Insight Centre for Data Analytics, University College Dublin, Dublin, Ireland. Electronic address: Cailbhe.doherty@ucdconnect.ie.
authors.forename: Cailbhe
authors.initials: C
authors.lastname: Doherty
authors.affiliation: Insight Centre for Data Analytics, University College Dublin, Dublin, Ireland. Electronic address: liang.zhao@ucdconnect.ie.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Ryan
authors.affiliation: Fujitsu Laboratories Ltd., Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Komaba
authors.affiliation: Fujitsu Laboratories Ltd., Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Inomata
authors.affiliation: Insight Centre for Data Analytics, University College Dublin, Dublin, Ireland.
authors.forename: Brian
authors.initials: B
authors.lastname: Caulfield
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D001924:Brain Concussion / Q000503:physiopathology / Q000523:psychology*; D015331:Cohort Studies; D004576:Electromyography; D005121:Extremities / Q000503:physiopathology; D005260:Female; D005528:Foot / Q000503:physiopathology; D007839:Functional Laterality; D005684:Gait; D006801:Humans; D007866:Leg / Q000503:physiopathology; D008297:Male; D004856:Postural Balance; D011597:Psychomotor Performance; D012447:Sacrum / Q000503:physiopathology; D057566:Self Report; D055815:Young Adult
keywords: Biomechanics; Brain concussion; Gait; Kinetics; Postural balance