Global Mobility Task: index for evaluating motor impairment and motor rehabilitation programs in Parkinson's disease patients

Abstract

Objective: In this study, the validity of a motor task, i.e., the Global Mobility Task (GMT), was assessed in a group of Parkinson's disease (PD) patients.

Patients and methods: Fifty-eight PD patients (mean age: 68.7 years) and 18 healthy subjects (mean age: 65.8 years) were enrolled in the study. The GMT measures the ability of an adult to roll over on the floor and stand up in five steps using two parameters: 'Time' and 'Score', i.e., the time needed and the ability to perform each step of the task. As the GMT has never been evaluated before, internal consistency and concurrent and discriminative validity were considered in assessing its characteristics in a group of PD patients at the beginning and at the end of a motor rehabilitation program. To determine whether the GMT could also quantify the extrapyramidal impairment, we compared data collected using this task with data obtained using clinical scales such as the Unified Parkinson's Disease Rating Scale III (UPDRS part III) and Hoehn & Yahr's score.

Results: Results showed that the GMT had good consistency and inter-rater reproducibility, was closely related to clinical scales and was able to detect the amelioration of extrapyramidal symptoms at the end of the motor rehabilitation program.

Conclusion: we propose the GMT as a tool for measuring impaired mobility in PD patients and for evaluating the objective effects of motor rehabilitation programs.