Effects of Two Different Types of Ankle Foot Orthoses on Gait Outcomes in Patients With Subacute Stroke.

Introduction: Stroke is a leading cause of death and disability in the world today. About 795,000 people are diagnosed with stroke yearly in the United States. The annual cost of stroke from medical services and disability in our nation is $ 38.6 billion dollars. Gait rehabilitation is an important aspect of neurorehabilitation with focus on attaining the most functional and symmetrical gait to prevent falls from faulty gait mechanics, and to prevent sedentary life styles and associated comorbidities. Ankle foot orthoses (AFOs) are commonly prescribed in patients with stroke to address ankle and knee instabilities and to restore a normal and safe walking pattern.The effectiveness of AFOs on various gait parameters has been reported in patients with stroke, but mostly during the chronic stages of recovery. Systematic analyses have shown that use of various types of ankle foot orthoses improve walking impairments and balance, reduce energy costs, and improve knee and ankle kinematics in people in the chronic stage of stroke recovery, greater than 6 months since the onset of stroke. It is reported that the majority of the gait improvements occur within the first 6 months following the onset of stroke. However, a limited number of studies have investigated the effects of AFOs within six months of stroke onset.

Three reported studies have investigated the effects of using an AFO compared to not using an AFO within 6 months following onset of stroke. Rao et al found that the use of an AFO significantly improved gait velocity, cadence and step length on the affected and unaffected side. Hyun et al. found that using an AFO significantly improved VO2 peak and 6 minute walk test scores . Carse et al showed significant improvement in walking velocity, average step length and cadence with use of AFO. There is only one reported study which looked at the effects of using two different types of AFOs during the subacute stage of stroke, less than 6 months following onset. Results of this study showed that gait speed and knee and ankle control were significantly higher in the Chignon AFO group compared to the polypropylene AFO group. Additionally, participants in the Chignon AFO group had significantly lower spasticity than those in the polypropylene AFO group.

In a recent case series report, investigators observed that using a custom Double Adjustable AFO during the early stages of recovery after stroke resulted in more typical muscle activation patterns, gait endurance and velocity, and near normal symmetry during gait without an assistive device or an AFO in three participants. The use of this type of AFO for gait rehabilitation following stroke in the subacute stages has not been thoroughly studied.

Statement of the Problem Patients with stroke resulting in hemiparesis and foot drop are affected by gait impairments such as poor symmetry, decreased velocity, and decreased endurance. AFOs have been shown to be an effective intervention for improving gait parameters in individuals who are in the chronic stage of stroke recovery. Although, the majority of gait improvements occur within six months of stroke, the effect of early bracing with different types of AFOs on gait outcomes has not been investigated thoroughly.

Purpose of the study: