Changes in Parkinsonian gait kinematics with self-generated and externally-generated cues: a comparison of responders and non-responders.

Rhythmic auditory stimulation such as listening to music can alleviate gait bradykinesia in people with Parkinson disease (PD) by increasing spatiotemporal gait features. However, evidence about what specific kinematic alterations lead to these improvements is limited, and differences in responsiveness to cueing likely affect individual motor strategies. Self-generated cueing techniques, such as singing or mental singing, provide similar benefits but no evidence exists about how these techniques affect lower limb joint movement. In this study, we assessed immediate effects of external and self-generated cueing on lower limb movement trajectories during gait. Using 3D motion capture, we assessed sagittal plane joint angles at the hip, knee, and ankle across 35 participants with PD, divided into responders ( = 23) and non-responders ( = 12) based on a clinically meaningful change in gait speed. Joint motion was assessed as overall range of motion as well as at two key time points during the gait cycle: initial contact and toe-off. Responders used both cue types to increase gait speed and induce increases in overall joint ROM at the hip while only self-generated cues also increased ROM at the ankle. Increased joint excursions for responders were also evident at initial contact and toe-off. Our results indicate that self-generated rhythmic cues can induce similar increases in joint excursions as externally-generated cues and that some people may respond more positively than others. These results provide important insight into how self-generated cueing techniques may be tailored to meet the varied individual needs of people with PD.