The purpose of this study was to estimate, using the Position-Specific Global Index (PSGI) of Lower-Limb Muscle Strength, the extent to which muscle strength is independently associated with functional walking capacity. We performed an observational, cross-sectional study with 63 patients poststroke (onset between 3 and 12 months) at a major teaching hospital in an urban Canadian city. We assessed functional walking capacity with the six-minute walk test (6MWT) and muscle strength with handheld dynamometry. We established the relationship between the lower-limb muscles and functional walking capacity with the PSGI. The PSGI explained 70% (p < 0.001) of the variability in the 6MWT, whereas the index of alternate against-gravity muscle strength explained 39% and the hip flexors in a supine position explained 51%.