The WalkAide Functional Electrical Stimulation system was found to be equivalent to an ankle-foot orthosis for improvements in gait speed and stroke related quality of life measures, according to study results published in Neurorehabilitation and Neural Repair.
“Based on clinical evidence and support in the scientific research, we expected the WalkAide (Innovative Neurotronics, Austin, Texas) to perform at least as well as the [ankle foot orthosis] AFO and to provide a safe and effective treatment for foot drop post-stroke,” Helen Rogers, PT, PhD, director of clinical research and training at Innovative Neurotronics, said. “The primary endpoints of the study were met and our results did in fact prove that the WalkAide is as effective as the AFO for improving gait speed and endurance. The devices were equivalent as well in their effect on quality of gait and quality of life.”
WalkAide vs. AFO
Researchers randomly assigned 495 Medicare-eligible individuals who were at least 6 months post-stroke with foot drop to wear either the WalkAide Functional Electrical Stimulation (FES) system or an AFO for 6 months. Primary endpoints included 10-meter walk test, a composite of the Mobility, Social Participation, and Activities of Daily Living/Instrumental Activities of Daily Living domain scores of the Stroke Impact Scale (SIS) and device-related serious adverse event rate. Secondary endpoints included the 6-minute walk Test, GaitRite Functional Ambulation Profile, Modified Emory Functional Ambulation Profile, Berg Balance Scale, Timed Up and Go, individual SIS domains and stroke-specific quality of life measures. Researchers used intention-to-treat analyses with primary endpoints tested for noninferiority and secondary endpoints tested for superiority.
Overall, 399 patients completed the multicenter study. Researchers found the WalkAide proved noninferior to the AFO for all primary endpoints. Study results showed statistically significant improvements for the 10-meter walk test in both groups. In the WalkAide group there were statistically significant improvements in the SIS composite score, total Modified Emory Functional Ambulation Profile score, individual floor and obstacle course time scores of the Modified Emory Functional Ambulation Profile, GaitRite Functional Ambulation Profile and Berg Balance Scale. However, researchers found no statistically significant differences between the FES and AFO groups.
Although the WalkAide is already used for other upper motor neuron lesions, including incomplete spinal cord injury, multiple sclerosis, acquired brain injury and cerebral palsy, according to Rogers, reimbursement for the WalkAide based on the results of this particular study would most likely be limited to foot drop caused by stroke. “It is difficult to gauge or predict coverage scope or timelines, but we are committed to utilizing the data as part of an overall effort to change the current National Coverage Determination to include patients with stroke and resultant foot drop,” Rogers told O&P Business News.
Treatment differences
According to Rogers, one of the primary differences between FES and AFO is how the devices alleviate foot drop. While AFO passively holds a joint in a given position, FES facilitates an active contraction of the dorsiflexor muscles, which helps prevent muscular atrophy, maintain normal joint range of motion, stimulate circulation and improve sensory feedback.
“All of these not only contribute to muscle and joint health but also may contribute to improvements in neurological function, known as neuroplasticity. Some of these positive changes have been seen even after the FES is removed, lending support to a therapeutic as well as neuroprosthetic effect of FES. Passive correction of foot drop via bracing does not allow for stimulation of the neuromuscular system and does not facilitate changes in the system,” Rogers said. “Further studies could be conducted to assess the full impact of repetitive FES on muscle function, voluntary muscle control and neuroplasticity, and to understand how FES could be utilized to maximize neuromuscular recovery in patients with stroke.” — by Casey Tingle
Disclosure: Rogers is clinical director of research and training for Innovative Neurotronics, manufacturer of the WalkAide.
