Extraction of the pull force from inertial sensors during the pull test for Parkinson's disease: A reliability study.

OBJECTIVE: To examine the inter- and intra-rater reliability of the pull test in patients with Parkinson's disease (PD) using the extracted pull force. METHODS: In this inter- and intra-rater reliability study, two raters performed a pull test on 30 patients with PD. The pull force was quantified using inertial sensors attached to the rater's right hand and the patient's lower trunk. In this study, the pull force was calculated as an extracted three-dimensional vector quantity, the resultant acceleration, and was expressed in m/s2. Inter- and intra-rater reliabilities were analyzed using the interclass correlation coefficient (ICC) for the pull force and Cohen's weighted kappa (κw) for the pull test score. Furthermore, Bland-Altman analysis was used to investigate systematic errors. RESULTS: The inter- and intra-rater reliability of the pull force was very poor (ICC = 0.033-0.214). Bland-Altman analysis revealed no systematic errors in the pull forces between the two test points. Conversely, κw for the pull test scores ranged from 0.763 to 0.920, indicating substantial to almost perfect agreement. CONCLUSION: The pull test score was reliable despite variations in the quantified pull force for inter- and intra-rater reliability. Our findings suggest that the pull test is a robust tool for evaluating postural instability in patients with PD and that the pull force probably does not affect scoring performance.

[An examination of the fall risk classification model in short-term intensive inpatient rehabilitation for elderly patients with Parkinson's disease].

AIM: To examine the predictive model that classifies the fluctuation in fall risk two weeks after an evaluation at the beginning of short-term intensive inpatient rehabilitation for elderly patients with Parkinson's disease (PD). METHODS: Of the patients with PD ≥65 years old who underwent intensive rehabilitation, 17 patients (mean age: 76.5±6.1 years old) who had a fall risk detected by the Timed "Up & Go" including a cognitive task (TUG-cognitive) were enrolled in this study. The patients were divided into two groups depending on the TUG-cognitive two weeks after starting intensive rehabilitation: reduced fall risk or residual fall risk. The differences in the evaluated items between the two groups were examined, and those items found to have significant differences were used as independent variables in the logistic regression analysis with the fluctuation in fall risk after two weeks as the dependent variable. RESULTS: A logistic regression analysis revealed that the fast-walking speed was a factor affecting the fluctuation in fall risk. In addition, the incidence of residual fall risk was calculated from the logistic function, and the risk was determined to be high when the fast-walking speed was ≤0.84 m/sec. CONCLUSIONS: The predictive model consisted of the TUG-cognitive and fast-walking speed at the beginning of intensive rehabilitation; it was suggested that the fluctuation in fall risk after two weeks could be classified based on these findings. Improvement of the fast-walking speed is important for reducing the fall risk in elderly patients with PD.

The power of instruction on retropulsion: A pilot randomized controlled trial of therapeutic exercise focused on ankle joint movement in Parkinson's disease.

Introduction: Although retropulsion is a serious complication of Parkinson's disease (PD), it is unknown whether ankle joint movement patterns can be targeted to treat retropulsion. The primary aim of this study was to investigate the effectiveness of therapeutic exercise focused on instructions regarding ankle joint movement on retropulsion in PD. Methods: Twenty patients with moderate PD were randomly allocated to the experimental intervention (INSTR) or control groups. The INSTR group received a 2-week therapeutic exercise program (40 min/day, five times/week) that involved repeated backward pulls on the shoulders with instructions to land on the toes as a response, and the control group received the same intervention without the instructions. The primary outcome was the difference in changes from baseline in the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS part III) score between the study groups at weeks 1 and 2. Results: The improvement in the MDS-UPDRS part III scores was significantly greater for the INSTR group in the week 1 (p = 0.033, pη2 = 0.241) and week 2 (p = 0.004, pη2 = 0.401) assessments. However, the provision of instructions to land on the toes as a backward response induced improvement in the only scores related to the backward response, and no significant between-group differences were observed in the other outcomes. Conclusion: The 2-week therapeutic exercise program with instructions to treat retropulsion improved the backward response. Trial registration: UMIN-CTR, UMIN000042722.