Walking performance and muscle strength in the later stage poststroke: a nonlinear relationship

Area of Science:

• Neurology
• Rehabilitation Medicine
• Biomechanics

Background:

• Stroke survivors often experience long-term motor deficits, including impaired walking.
• Lower extremity muscle weakness is a common consequence of stroke, affecting functional mobility.

Purpose of the Study:

• To investigate the relationship between lower extremity muscle strength and walking performance (speed and distance) in individuals in the later stages of stroke recovery.
• To compare the muscle strength and walking performance of post-stroke subjects with a healthy reference group.

Main Methods:

• A cross-sectional observational study involving 41 post-stroke subjects and 144 healthy controls.
• Muscle strength was quantified using an isokinetic dynamometer to derive a strength index.
• Walking performance was assessed via the 30-meter walk test (self-selected and maximum speed) and the 6-minute walk test.

Main Results:

• Post-stroke subjects demonstrated significantly lower lower extremity strength (strength index: 730±309) compared to the healthy group (1112±362).
• A nonlinear association was observed between muscle strength and walking performance in both groups.
• Muscle strength explained a substantial portion of the variance in walking speed (37-63%) and 6-minute walk test distance (44%) in the stroke group.

Conclusions:

• Individuals in the later stage post-stroke are weaker and exhibit poorer walking performance than healthy peers.
• Reduced muscle strength is a key factor contributing to decreased walking speed and distance after stroke.
• These findings support the continued development of strength-focused interventions to enhance walking ability in stroke survivors.