EFFECTS OF BACKWARD WALKING TRAINING ON NEUROMUSCULAR EFFICIENCY IN GAIT IN AN INDIVIDUAL POST-STROKE

Abstract

Background & Purpose: Kinematic analysis of backward walking provides evidence that lower extremity muscle activity and dorsiflexion ROM is greater during backward walking. It has been suggested that the same central pattern generator controls both forward and backward gait indicating adaptability. Training an individual backward may provide neural adaptability which improves neuromuscular efficiency. A study by Yang, et al. found that a program of backward walking in parallel bars significantly increased speed, step length, and stride length in a group of individuals with hemiparesis as a result of stroke. No study has explored the benefits of a program of backward walking utilizing the treadmill. The purpose of this study was to explore the benefit of walking backward on a treadmill on gait outcomes in an individual post-stroke. Case Description: The subject was a 58-year-old male 10 months post-right stroke who was an independent community ambulator. He wore an articulating AFO on the left and did not use an assistive device. Pre-test, Post-test, and 2 month post retention measures were: lower extremity motor score of the Fugl-Meyer Assessment Scale, Dynamic Gait Index, 10 meter walk test, Six minute walk test, stride and step lengths, and submaximal VO2 measured while walking forward on a treadmill at 1 MPH, 0% grade. The subject walked backward on a Biodex 400TM forward/retro treadmill at a self selected speed for 30 minute sessions three times/week for six weeks. The subject was allowed to rest as needed during the 30 minute sessions. BP, HR, and RPE were monitored during the 30 minute sessions. Outcomes: Main outcomes at post-test were a 25% decrease in 10 meter walk test time and a 9% increase in six minute walk test distance. Stride length on the right increased by 17% and the left by 5%. There was no change in VO2. Retention outcomes showed slight improvement over the post-test results on the 10 meter walk test, stride length, and step length. Distance on the 6 minute walk test improved by 23% over the post-test. An ANOVA of the mean VO2 values showed a significant decrease (p< 0.01) over the post-test results at the same absolute submaximal workload. Discussion: The post-test increase in speed on the 10 meter walk test along with the increase in distance on the six minute walk test suggests that the differences were due, in part, to neuromusculoskeletal changes. The decrease in VO2 on the retention test further suggests that the improvements were due to changes in neuromuscular efficiency rather than fitness. Neuromusculoskeletal factors that could have contributed to the post-test and retention changes include increased dorsiflexion ROM, increased pelvic mobility, increased knee extensor strength, increased plantarflexor peak torque, and decreased plantarflexor spasticity. Results from this study suggest that a program of backward walking may improve efficiency of gait in individuals post-stroke and should be investigated further.