Responsiveness of Objective vs. Clinical Balance Domain Outcomes for Exercise Intervention in Parkinson's Disease

Abstract

Background: Balance deficits in people with Parkinson's disease (PD) are often not helped by pharmacological or surgical treatment. Although balance exercise intervention has been shown to improve clinical measures of balance, the efficacy of exercise on different, objective balance domains is still unknown. Objective: To compare the sensitivity to change in objective and clinical measures of several different domains of balance and gait following an Agility Boot Camp with Cognitive Challenges (ABC-C) intervention. Methods: In this cross-over, randomized design, 86 individuals with PD participated in 6-week (3×/week) ABC-C exercise classes and 6-week education classes, consisting of 3-6 individuals. Blinded examiners tested people in their practical off state. Objective outcome measures from wearable sensors quantified four domains of balance: sway in standing balance, anticipatory postural adjustments (APAs) during step initiation, postural responses to the push-and-release test, and a 2-min natural speed walk with and without a cognitive task. Clinical outcome measures included the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III, the Mini Balance Evaluation Systems Test (Mini-BESTest), the Activities of Balance Confidence (ABC), and the Parkinson's Disease Questionnaire (PDQ-39). The standardized response means (SRM) of the differences between before and after each intervention compared responsiveness of outcomes to intervention. A linear mixed model compared effects of exercise with the active control-education intervention. Results: The most responsive outcome measures to exercise intervention with an SRM > 0.5 were objective measures of gait and APAs, specifically arm range of motion, gait speed during a dual-task walk, trunk coronal range of motion, foot strike angle, and first-step length at step initiation. The most responsive clinical outcome measure was the patient-reported PDQ-39 activities daily living subscore, but all clinical measures had SRMs <0.5. Hasegawa et al. Objective vs. Clinical Balance Outcomes Conclusions: The objective measures were more sensitive to change after exercise intervention compared to the clinical measures. Spatiotemporal parameters of gait, including gait speed with a dual task, and APAs were the most sensitive objective measures, and perceived functional independence was the most sensitive clinical measure to change after the ABC-C exercise intervention. Future exercise intervention to improve gait and balance in PD should include objective outcome measures.

Validity and Reliability of a Smartphone App for Gait and Balance Assessment

“…In addition, these standardized clinical scales are prone to ceiling effects [ 14 , 15 , 16 ], which limit their ability to discriminate between different balance levels at their higher-end, especially for individuals with high scores at the onset of rehabilitation. These constraints can reduce the responsiveness of the clinical scales to small changes that occur during rehabilitation or as a result of a change in health condition [ 17 , 18 ].…”

Effects of a Cognitively Challenging Agility Boot Camp Program on Balance and Gait in People With Parkinson’s Disease: Does Freezing of Gait Status Matter?

“…The group exercise classes were targeted to be between 3 and 6 people per class. 24,25 Education intervention consisted of a 90-minute group session, once a week for 6 weeks in which participants were taught how to live better with their chronic conditions. Inclusion criteria were: (1) diagnosis of PD by movement disorders specialists according to the United Kingdom Brain Bank criteria; (2) 50 to 90 years of age; (3) mild to moderate PD; (4) on stable antiparkinsonian medication; (5) without major musculoskeletal, peripheral, or central nervous system disorders (other than PD) that could significantly affect their balance and gait; (6) without excessive use of alcohol or recreational drugs; (7) without history of structural brain disease, active epilepsy, stroke, or dementia that would interfere with consent or ability to follow testing procedures; (8) able to stand or walk for 2 minutes without an assistive device.…”

“…We have recently identified a set of objective measures of balance and gait, calculated with wearable inertial measurement units (IMUs) 24 sensors, that optimally discriminate people with PD from healthy control subjects. For such purpose, we used the baseline assessment prior to the ABC-C program.…”

“…Subsequently, we investigated the effect of the ABC-C program on the same objective (from IMUs) and clinical measures and showed that objective measures had a higher effect size compared to the clinical measures. 24,25 These results are promising, but to reach the full potential of nonpharmacological interventions, the clinicians need to know which specific people with PD (eg, those with or without FoG) would benefit most from this rehabilitation intervention.…”

Discriminative Mobility Characteristics between Neurotypical Young, Middle-Aged, and Older Adults Using Wireless Inertial Sensors

“…An evolving body of research has focused on identifying mobility characteristics associated with disability, which has been instrumental in devising efficacious rehabilitation strategies and clinical biomarkers [ 15 , 16 , 17 , 18 ]. Moreover, with the advancement of inertial measurement unit (IMU) technology and algorithm development, the capacity to objectively quantify and track mobility has greatly improved, providing an abundance of reliable spatiotemporal metrics capable of characterizing numerous mobility domains and activities of daily living (i.e., walking, turning, balancing, etc.)…”