PREDICTORS OF THE FUNCTIONAL REACH TEST IN PEOPLE WITH PARKINSON'S DISEASE

ABSTRACT Postural instability, a fundamental signal/symptom of Parkinson’s disease (PD), is characterized by the association between postural alignment, joint range of motion, and muscular rigidity. The aim of the present study was to analyze the relationship between performance in the functional reach test (FRT) and associated factors such as joint range of motion and PD clinical features. Twenty-five people with PD in stages 1 and 1.5 of the Hoehn & Yahr scale participated in the study. The analyzed dependent variables were: FRT performance and scores in the items of clinical evaluation of the Unified Parkinson’s Disease Rating Scale: pull-test, motor rigidity, and motor condition were used. The average distance in the FRT was 25.3 cm and the mean anterior-posterior displacement of the center of pressure was 2.69 cm. The ankle range of motion was associated with FRT performance, while postural stability was associated with the anterior-posterior displacement of the center of pressure during the FRT. We conclude that FRT performance in people with PD is determined by the individual level of balance and by the ankle joint amplitude and muscular rigidity and functional alterations due to aging are responsible for FRT performance.