title: Rhythm perturbations in acoustically paced treadmill walking after stroke.
abstract: BACKGROUND
  In rehabilitation, acoustic rhythms are often used to improve gait after stroke. Acoustic cueing may enhance gait coordination by creating a stable coupling between heel strikes and metronome beats and provide a means to train the adaptability of gait coordination to environmental changes, as required in everyday life ambulation.
  
  
  OBJECTIVE
  To examine the stability and adaptability of auditory-motor synchronization in acoustically paced treadmill walking in stroke patients.
  
  
  METHODS
  Eleven stroke patients and 10 healthy controls walked on a treadmill at preferred speed and cadence under no metronome, single-metronome (pacing only paretic or nonparetic steps), and double-metronome (pacing both footfalls) conditions. The stability of auditory-motor synchronization was quantified by the variability of the phase relation between footfalls and beats. In a separate session, the acoustic rhythms were perturbed and adaptations to restore auditory-motor synchronization were quantified.
  
  
  RESULTS
  For both groups, auditory-motor synchronization was more stable for double-metronome than single-metronome conditions, with stroke patients exhibiting an overall weaker coupling of footfalls to metronome beats than controls. The recovery characteristics following rhythm perturbations corroborated the stability findings and further revealed that stroke patients had difficulty in accelerating their steps and instead preferred a slower-step response to restore synchronization.
  
  
  CONCLUSIONS
  In gait rehabilitation practice, the use of acoustic rhythms may be more effective when both footfalls are paced. In addition, rhythm perturbations during acoustically paced treadmill walking may not only be employed to evaluate the stability of auditory-motor synchronization but also have promising implications for evaluation and training of gait adaptations in neurorehabilitation practice.
authors.affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University, Department of Rehabiliation Medicine, VU University Medical Centre, Amsterdam, the Netherlands. m.roerdink@fbw.vu.nl
authors.forename: Melvyn
authors.initials: M
authors.lastname: Roerdink
authors.forename: Claudine J C
authors.initials: CJ
authors.lastname: Lamoth
authors.forename: Joost
authors.initials: J
authors.lastname: van Kordelaar
authors.forename: Peter
authors.initials: P
authors.lastname: Elich
authors.forename: Manin
authors.initials: M
authors.lastname: Konijnenbelt
authors.forename: Gert
authors.initials: G
authors.lastname: Kwakkel
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Beek
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D020521:Stroke / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D016138:Walking