Residual Deficits of Knee Flexors and Plantar Flexors Predict Normalized Walking Performance in Patients with Poststroke Hemiplegia

Objectives: The aim of the study was to investigate the relation of lower limb muscle strength with normalized walking value, gait speed, and balance in patients with poststroke hemiplegia. Methods: Functional ambulatory unilateral hemiplegic patients were included in the study. Functionality of the lower limb was tested by Fugl-Meyer lower extremity motor subscale. Six-minute walk test (6MWT), 10-meter walk test, and Berg Balance Scale were performed to evaluate functional walking capacity, gait speed, and balance, respectively. Normalized 6MWT value was calculated by using a formula. Maximum isometric strengths of 8 muscle groups of both limbs were measured using a handheld dynamometry and residual deficits of the paretic side muscles were calculated. Results: The study population was comprised of 61 hemiplegic patients (mean age: 54.6 +/- 11.7 years and mean duration after stroke: 23.4 +/- 18.1 months). Mean normalized walking distance on 6MWT was 44.4% of expected. The residual deficits of the affected lower extremity muscles were negatively correlated with normalized 6MWT: hip flexors (r = -.651), hip extensors (r = -.621), hip abductors (r = -.657), hip adductors (r = -.630), knee flexors (r = -.738), knee extensors (r = -.659), ankle dorsiflexors (r = -.776), and ankle plantar flexors (r = -.773). Lower extremity residual deficits also showed moderate-strong negative correlations with Berg Balance Scores and gait speed. Multiple linear regression analyses showed that the residual deficits of the ankle plantar flexors and knee flexors are the major independent determinants of normalized 6MWT results (R .791 R-2 : 625). Conclusions: Residual deficits of lower extremity muscles-particularly of ankle dorsiflexors, plantar flexors, and knee flexors-are related to walking performance, gait speed and balance. Besides, knee flexors and plantar flexors are predictors of normalized 6MWT.