Quantifying Gait Parameters in Parkinson’s Disease and Essential Tremor via 3D Kinematics
Keerthana Nalamada1, Johnathan McKay1, Sofia Hefner2, Douglas Bernhard1, Richa Tripathi1, Stewart Factor1, Christine Esper1
1Department of Neurology, Emory University School of Medicine, 2Georgie Institute of Technology
Objective:
To compare gait parameters in a large cohort of Parkinson’s Disease (PD) and Essential Tremor (ET) patients using 3D kinematic analysis.
Background:
PD and ET are common movement disorders with gait abnormalities and associated morbidity, particularly in advanced disease. We aim to quantify gait parameters in these two conditions.
Design/Methods:
This retrospective study reviewed gait variables from a cohort of PD (n=245) and ET (n=123) patients who underwent 3D gait motion analysis (MA) between 2014 and 2022. Standard gait testing protocol included walking straight, with and without turns (≥5 cycles). Mean and standard deviation statistics for gait speed (m/s), cadence (steps/min), step length (cm), and step width (cm) were stratified by diagnosis, sex, and age. Differences in gait outcomes between PD and ET were assessed with linear models with terms for sex and age.
Results:
In 368 patients (67% PD; 33% ET), 34% were female and mean age was 65.7±10.5 years. After controlling for age and gender, linear models identified significant differences in gait speed (PD 85.9±31.5 cm/s vs. ET 92.6±25.3 cm/s, p=0.001), step length (PD 47.4±15.2 cm vs. ET 52.4±12.4 cm, p<<0.001), and step width (PD 11.8±3.4 cm vs. ET 12.9±4 cm, p=0.001) in PD compared to ET, but no difference in cadence (p=0.201). Female sex and increasing age were also associated with reduced gait speed and step length.
Conclusions:
This is a large 3D gait MA cohort comparing PD and ET patients, demonstrating reduced gait speed and step length in PD and increased step width in ET, consistent with known pathology. Further comparisons with a larger sample size to age matched norms, longitudinally within and across disease states, are important to establish quantitative measures of gait natural history evolution in PD and ET. These data may provide improved clinical management and outcomes to potentially reduce falls and increase quality of life.