Article

Acoustic rhythms are frequently used in gait rehabilitation, with positive instantaneous and prolonged transfer effects on various gait characteristics. The gait modifying ability of acoustic rhythms depends on how well gait is tied to
the beat, which can be assessed with measures of relative timing of
auditory-motor coordination. We examined auditory-motor coordination in 20
healthy elderly individuals walking to metronome beats with pacing frequencies
slower than, equal to, and faster than their preferred cadence. We found that
more steps were required to adjust gait to the beat, the more the metronome rate
deviated from the preferred cadence. Furthermore, participants anticipated the
beat with their footfalls to various degrees, depending on the metronome rate;
the faster the tempo, the smaller
the phase advance or phase lead. Finally, the
variability in the relative timing between footfalls and the beat was smaller for
metronome rates closer to the preferred cadence, reflecting superior
auditory-motor coordination.
These observations have three practical
implications. First, instantaneous effects of acoustic stimuli on gait
characteristics may typically be underestimated given the considerable number of
steps required to attune gait to the beat in combination with the usual short
walkways. Second, a systematic phase lead of footfalls to the beat does not
necessarily reflect a reduced ability to couple gait to the metronome. Third, the
efficacy of acoustic rhythms to modify gait depends on metronome rate. Gait is coupled best to the beat for metronome rates near the preferred cadence.
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Langue : ANGLAIS