title: Modality-specific, multitask locomotor deficits persist despite good recovery after a traumatic brain injury.
abstract: OBJECTIVE
  To study the effects of sensory modality of simultaneous tasks during walking with and without obstacles after moderate to severe traumatic brain injury (TBI).
  
  
  METHODS
  Group comparison study.
  
  
  METHODS
  Gait analysis laboratory within a postacute rehabilitation facility.
  
  
  METHODS
  Volunteer sample (N=18). Persons with moderate to severe TBI (n=11) (9 men, 3 women; age, 37.56+/-13.79 y) and a comparison group (n=7) of subjects without neurologic problems matched on average for body mass index and age (4 men, 3 women; age, 39.19+/-17.35 y).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Magnitudes and variability for walking speeds, foot clearance margins (ratio of foot clearance distance to obstacle height), and response reaction times (both direct and as a relative cost because of obstacle avoidance).
  
  
  RESULTS
  The TBI group had well-recovered walking speeds and a general ability to avoid obstacles. However, these subjects did show lower trail limb toe clearances (P=.003) across all conditions. Response reaction times to the Stroop tasks were longer in general for the TBI group (P=.017), and this group showed significant increases in response reaction times for the visual modality within the more challenging obstacle avoidance task that was not observed for control subjects. A measure of multitask costs related to differences in response reaction times between obstructed and unobstructed trials also only showed increased attention costs for the visual over the auditory stimuli for the TBI group (P=.002).
  
  
  CONCLUSIONS
  Mobility is a complex construct, and the present results provide preliminary findings that, even after good locomotor recovery, subjects with moderate to severe TBI show residual locomotor deficits in multitasking. Furthermore, our results suggest that sensory modality is important, and greater multitask costs occur during sensory competition (ie, visual interference).
authors.affiliation: Center for Interdisciplinary Research in Rehabilitation and Social Integration, Department of Rehabilitation, Faculty of Medicine, Laval University, Québec, Québec, Canada. brad.mcfadyen@rea.ulaval.ca
authors.forename: Bradford J
authors.initials: BJ
authors.lastname: McFadyen
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Cantin
authors.forename: Bonnie
authors.initials: B
authors.lastname: Swaine
authors.forename: Guylaine
authors.initials: G
authors.lastname: Duchesneau
authors.forename: Julien
authors.initials: J
authors.lastname: Doyon
authors.forename: Denyse
authors.initials: D
authors.lastname: Dumas
authors.forename: Philippe
authors.initials: P
authors.lastname: Fait
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D015992:Body Mass Index; D001930:Brain Injuries / Q000503:physiopathology / Q000523:psychology / Q000534:rehabilitation*; D005260:Female; D005684:Gait; D006801:Humans; D008124:Locomotion; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011930:Reaction Time; D020127:Recovery of Function; D013647:Task Performance and Analysis; D016138:Walking