Parkinson disease (PD) is the fastest growing source of disability among neurological disorders. Diminished physical activity is highly prevalent in PD and often lead to the onset of disability. Regular, habitual exercise is a critical component of the long-term PD management. However, PD-specific motor (e.g. slow and diminished movements, variable step timing) and non-motor (e.g. depression, apathy) problems collectively hinder physical activity. Rhythmic auditory stimulation (RAS) is a rehabilitation technique that employs the coupling of auditory cues with movement. When used during walking, RAS has been shown to benefit walking rhythmicity, quality, and speed. Therefore this rehabilitation technique can be advantageous in promoting moderate intensity walking activity. While clinical studies support RAS-based intervention, its translation to real-world, community-based environments and for long-term exercise for the promotion of physical activity is limited. The difference that determines viability of RAS for out-of-lab applications lie in the distinction between external entrainment (open-loop) versus autonomous entrainment (closed-loop). Open-loop RAS requires high levels of vigilance and is prone to error accumulation, which is problematic with gait dysfunction in PD. On the other hand, closed-loop RAS allows for natural and stable entrainment. A closed-loop approach in this case is a necessity of the task and a technological challenge to translate RAS to community-based settings. In this pilot, the investigators will utilize a breakthrough digital therapeutic that employs closed-loop RAS to alleviate PD-specific problems by regulating stepping patterns. Using music as a substrate for cue delivery, this digital therapeutic leverages gait benefits from RAS along with enjoyment of music listening, thus making it a viable and engaging modality that will yield habits of regular walking. The investigators posit that music that is linked to enjoyment serves as context cues that define the pre-condition to engaging in habitual walking exercise and increased physical activity. With repetition, these recurring contextual triggers (i.e. music) automatically evoke a habitual response of exercise, and thus has the potential to amplify physical activity.

The main aims of the study seek to examine if Amped-PD (Experimental Intervention) is more effective than a standard-of-care walking program (Active-Control Intervention) in improving physical activity based on moderate intensity walking (Aim 1), and in improving motor deficits related to quality of walking (Aim 2) in individuals with mild-to-moderate PD. Additionally, this study will examine whether habit formation mediates the relationship between the intervention (Amped-PD or Active-Control) and physical activity (Aim 3). The investigators hypothesize that Amped-PD will have greater improvements in amounts of moderate intensity walking and stride-to-stride variability based on stride length and swing time. Further, habit formation will be one mechanism that will explain the link between the intervention and physical activity. Secondary research aims will examine whether Amped-PD is more effective than Active-Control in improving motor and non-motor features based on short- and long-distance walking function, spatiotemporal measures of walking, step activity based on daily step counts, disease severity scores, quality of life, self-efficacy on walking, and depression.

This study will utilize the breakthrough digital music therapeutic developed and manufactured by MedRhythms (Portland, ME). To examine the effects of the intervention, the investigators will use clinical measures of motor and gait function, participant self-reports on habit formation, and quantified movement data on walking and physical activity using wearable sensors. This study will be implemented by carrying out the following study visits: (1) Primary screen over the phone, (2) Clinical Screening and Baseline Assessment, (3) Community-based, self-directed walking program (6 weeks), (3) Post-training Assessment; (4) Follow-up training (2 weeks), and (5) Final Follow-Up Assessment. Altogether, these procedures may take up to 10 weeks.