Musical pleasure beneficially alters stride and arm swing amplitude during rhythmically-cued walking in people with Parkinson's disease

Entrainment of walking to rhythmic auditory cues (e.g., metronome and/or music) improves gait in people with Parkinson's disease (PD). Studies on healthy individuals indicate that entrainment to pleasant musical rhythm can be more beneficial for gait facilitation than entrainment to isochronous rhythm, potentially as a function of emotional/motivational responses to music and their associated influence on motor function. Here, we sought to investigate how emotional attributes of music and isochronous cues influence stride and arm swing amplitude in people with PD. A within-subjects experimental trial was completed with persons with PD serving as their own controls. Twenty-three individuals with PD walked to the cue of self-chosen pleasant music cue, pitch-distorted unpleasant music, and an emotionally neutral isochronous drumbeat. All music cues were tempo-matched to individual walking pace at baseline. Greater gait velocity, stride length, arm swing peak velocity and arm swing range of motion (RoM) were found when patients walked to pleasant music cues compared to baseline, walking to unpleasant music, and walking to isochronous cues. Cued walking in general marginally increased variability of stride-to-stride time and length compared with uncued walking. Enhanced stride and arm swing amplitude were most strongly associated with increases in perceived enjoyment and pleasant musical emotions such as power, tenderness, and joyful activation. Musical pleasure contributes to improvement of stride and arm swing amplitude in people with PD, independent of perceived familiarity with music, cognitive demands of music listening, and beat salience. Our findings aid in understanding the role of musical pleasure in invigorating gait in PD, and inform novel approaches for restoring or compensating impaired motor circuits.