Determining the cut-off value for knee extensor strength for identifying independence in gait in chronic stroke survivors

Abstract

Objective: To determine the cut-off values for knee extensor strength on the paretic and non-paretic sides and both sides combined for identifying independence in gait in chronic stroke survivors. Design: Cross-sectional study. Patients: Sixty chronic stroke survivors. Methods: Functional Independence Measure (FIM) gait scores were measured, and the participants were allocated to the independent group (FIM gait score 6 or 7) or the dependent group (FIM gait score 1?5). Knee extensor strength on the paretic and non-paretic sides was measured using a handheld dynamometer. Results: Eighteen stroke survivors were allocated to the independent group and 42 to the dependent group. The receiver operating characteristic curve analyses revealed that the cut-off values for knee extensor strength were 0. 46 Nm/kg (sensitivity 83% and specificity 67%; area under the curve (AUC) 0. 816) on the paretic side, 0. 65 Nm/kg (sensitivity 89% and specificity 55%; AUC 0. 738) on the non-paretic side and 1. 31 Nm/kg (sensitivity 83% and specificity 74%; AUC 0. 811) for both sides combined. Conclusion: These cut-off values could help to identify stroke survivors who are no longer independent in gait because of decreasing knee extensor strength on the paretic and non-paretic sides.