Walking velocity and modified rivermead mobility index as discriminatory measures for functional ambulation classification of chronic stroke patients.

Background: The cut-off values of walking velocity and classification of functional mobility both have a role in clinical settings for assessing the walking function of stroke patients and setting rehabilitation goals and treatment plans.

Objective: The present study investigated whether the cut-off values of the modified Rivermead Mobility Index (mRMI) and walking velocity accurately differentiated the walking ability of stroke patients according to the modified Functional Ambulation Category (mFAC).

Methods: Eighty two chronic stroke patients were included in the study. The comfortable/maximum walking velocities and mRMI were used to measure the mobility outcomes of these patients. To compare the walking velocities and mRMI scores for each mFAC point, one-way analysis of variance and the post-hoc test using Scheffe's method were performed. The patients were categorized according to gait ability into either $\text{mFAC}=\text{VII}$ or mFAC $\le$ VI group. The cut-off values for mRMI and walking velocities were calculated using a receiver-operating characteristic curve. The odds ratios of logistic regression analysis (Wald Forward) were analyzed to examine whether the cut-off values of walking velocity and mRMI can be utilized to differentiate functional walking levels.

Results: Except for mFACs III and IV, maximum walking velocity differed between mFAC IV and mFAC V $(p<0.01)$ , between mFAC V and mFAC VI $(p<0.001)$ , and between mFAC VI and mFAC VII $(p<0.05)$ . The cut-off value of mRMI is $>26.5$ and the area under the curve is 0.87, respectively; the cut-off value for comfortable walking velocity is $>0.77$ m/s and the area under the curve is 0.92, respectively; also, the cut-off value for maximum walking velocity is $>0.92$ m/s and the area under the curve is 0.97, respectively. In the logistic regression analysis, the maximum walking velocity $(>0.92$ m/s, $\text{OR}=22.027)$ and mRMI $(>26.5$ scores, $\text{OR}=10.283)$ are able to distinguish $\text{mFAC}=\text{VII}$ from mFAC $\le$ VI.

Conclusion: The cut-off values of maximum walking velocity and mRMI are recommended as useful outcome measures for assessing ambulation levels in chronic stroke patients during rehabilitation.