JMIR Publications

ABSTRACT

Background:

Gait impairment, including shuffling gait, and hesitation, is common in people with Parkinson’s disease (PD), and have been linked to increased fall risk, and freezing of gait in this cohort. Nowadays the gait metrics majorly focused on the other spatio-temporal characteristics of gait, but less is known to the angular characteristics of the gait, which may provide helpful information pertaining to the functional status and the effects of the treatment in PD.

Objective:

We here aimed to quantify the angles of steps during walking and explore if this novel step angle metric is associated with the severity of PD, and the effects of the treatment, including acute levodopa challenge test (ALCT) and deep brain stimulation (DBS).

Methods:

Eighteen participants with PD completed the walking test before and after ALCT, and another twenty-five participants with PD completed the test when DBS is on and off. The walking test was implemented under two conditions: walking normally at preferred speed (single task) and walking while performing a cognitive serial subtraction task (dual task). Seventeen age-matched non-PD participants also completed this walking test. The angular velocity was measured using wearable sensors on ankles, and three gait angular metrics were obtained, that is, mean step angle, initial step angle and last step angle. The conventional gait metrics (i.e., step time and step number) were also calculated.

Results:

The results showed that compared to control, these three step angle metrics (mean step angle, F=69.75, p<.001, η2 p= 0.59; initial step angle, F=15.56, p<.001, η2 p=0.25; last step angle, F=61.99, p<.001, η2 p=0.56) was significantly smaller in those with PD. Within the PD cohort, Both ALCT and DBS induced greater mean step angle (ACLT: F=5.77, p=.021, η2 p=0.13; DBS: F=8.53, p=.005, η2 p=0.14) and last step angle (ACLT: F=10, p=.003, η2 p=0.21; DBS: F=4.96, p=.003, η2 p=0.09), while no significant changes were observed in step time and number after the DBS. Additionally, these step angles were correlated with Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III) score.

Conclusions:

This pilot study demonstrated that the gait angular characteristics, as quantified by the step angles, are sensitive to the disease severity of PD and more importantly, can capture the effects of the treatment on the gait while the traditional metrics cannot, indicating that these metric may serve as novel markers to help the assessment of gait in those with PD as well as the rehabilitation of this vulnerary cohort.