Differences in predictors for gait speed and gait endurance in Parkinson's disease.

Introduction: Both gait speed and gait endurance directly impact independence and community engagement for individuals with Parkinson's disease (PD). However, factors accounting for variability in gait speed and gait endurance performance are unclear. The purpose of this study was to investigate whether key factors associated with gait speed in individuals with PD also predicted gait endurance.

Methods: Community dwelling ambulatory individuals with PD were recruited for a single session. Key measures included 10 Meter Walk Test (10MWT) and 6 Minute Walk Test (6MWT) and key factors: age, disease severity [Movement Disorders Society United Parkinson's Disease Rating Scale (motor scale only) (MDS-UPDRS motor)], plantar flexor strength [Calf Raise Senior (CRS)], fatigue [Fatigue Severity Scale (FSS)], cognition [Montreal Cognitive Assessment (MoCA)], and balance [Four Square Step Test (FSST)]. Multiple linear regression analyses were conducted to determine clinical relationships.

Results: Seventy-two individuals with PD (mean (standard deviation) (age = 70.83 (7.91) years; 50 males; MDS-UPDRS motor = 30.67 (13.50)) completed all assessments. The model predicting gait speed was significant, F(6, 65) = 15.143, p <.001, accounting for 54 % of the variance. Of the predictor variables age, MDS-UPDRS motor, CRS, MoCA and FSST scores were significant predictors. The model predicting gait endurance was significant, F(6, 65) = 15.608, p <.001, accounting for 55 % of the variance. Of the predictor variables, age, MDS-UPDRS motor scale, and CRS scores were significant predictors.

Discussion: Gait speed and gait endurance are similarly influenced by age, motor impairment, and plantarflexion strength. However, cognition and balance were predictors only of gait speed, which may suggest unique task differences exist between gait speed and gait endurance.