The relationship between lower limb muscle strength and balance with functional walking capacity in post-stroke hemiplegic patients

Aims: The aim of the study was to investigate whether the residual deficits of the effected lower limb muscles are related with balance, functional walking capacity and normalized walking value in post-stroke hemiplegic patients. Methods: Functional ambulatory unilateral hemiplegic patients (3-60 months post stroke) were included into the study. Fugl-Meyer lower extremity motor subscale score, Brunnstrom's recovery stage and lower extremity manual muscle test scores were noted. 6 minute walk test was performed to determine functional walking capacity, 10 meter walk test and Berg Balance Scale were performed in order to determine gait speed and balance status of the patient. Maximum isometric strengths of eight muscle groups of both limbs were measured using a handheld dynamometry and residual deficits of the affected side muscles were calculated. 6 minute walk test results were expressed as percentages of expected normal values using reference equations of height, weight, age and sex matched healthy population (normalized 6 minute walking value). Results: The study population was comprised of 61 hemiplegic patients with mean age 54,64±11,67 years and mean time after stroke 23,4±18,1 months. 59 percent (nmale: 36) of the study group were male. Berg Balance scores were 42 (20-56), 6 minute walking distance was 253,43 (40,50-435,00) m, normalized walking values had a mean value of 44,4±23,4 and gait speeds were 0,91 m/sn (0,15-1,67). The residual deficits of the affected lower extremity muscle strengths were all negatively correlated with normalized walking value: hip flexors (r=-,651), hip extansors (r=-,621), hip abductors (r=-,657), hip adductors (r=-,630), knee flexors (r=-,738), knee extansors (r=-,659), ankle dorsiflexors (r=-,776) and ankle plantarflexors (r=-,773). Moderate to strong positive correlations between normalized walking value and Berg Balance Scores, 6 minute walk distance and gait speed were found in this study (r=,688; r=,950; r=,924; respectively). Multiple lineer regression analyses showed that the residual deficits of the ankle plantar flexors and knee flexors are the major independent determinants of normalized 6 minute walking value (R:,791 R2: 625). Conclusions: Lower extremity muscle strength and balance are related to walking performance. Resistance training of the lower limb muscles should be targeted in order to improve walking performance, particularly to ankle plantar flexors and knee flexors in patients with stroke. Key Words: Rehabilitation; Stroke, Strength, Walking, Balance.