The Effects of Metronome Frequency Differentially Affects Gait on a Treadmill and Overground in People with Parkinson Disease

Abstract Background Treadmills and rhythmic auditory cueing can influence stepping rhythm for individuals with Parkinson disease (PD). Of concern, however, is that auditory cueing directly addresses the temporal features of gait, whereas adjusting step length may be more important for people with PD. Stepping to a faster cadence when walking overground may increase gait speed, but without requiring an increased step length. Furthermore, given the potentially valuable role of walking on a treadmill for individuals with PD, we are concerned that increasing cadence with rhythmic auditory cueing while walking at a constant treadmill speed will induce even shorter steps. Research question What is the effect of different metronome cue frequencies on spatiotemporal gait parameters when walking overground compared to walking on a treadmill in people with PD? Methods Using a repeated-measures design, 21 people with PD (stage 1-3) walked overground and on a treadmill with and without metronome cues of 85%, 100%, and 115% of their baseline cadence frequency for one minute each. We assessed step length, and cadence during all conditions. Gait speed was assessed during overground gait. Results An interaction effect between cue frequency and walking environment revealed that participants took longer steps during the 85% condition on the treadmill only. When walking overground, metronome cues of 85% and 115% of baseline cadence yielded decreases and increases, respectively, in both cadence and gait speed with no associated change in step length. Significance These data suggest that people with PD are able to alter spatiotemporal gait parameters immediately when provided the appropriate metronome cue and walking environment. We propose to target shortened step lengths by stepping to the beat of slow frequency auditory cues while walking on a treadmill, whereas the use of fast frequency cues during overground walking can facilitate faster walking speeds.