To assess the effectiveness of a new stimulator (WalkAide) for the treatment of foot drop. The comparison will involve physical measurements (e.g. walking speed, physiological cost index, Modified Rivermead Mobility Index, etc.) and questionnaires on the quality of life and acceptance of the technology by stroke survivors.
Stroke is the third leading cause of death in the United States and other developed countries and a major source of disability, often leading to hospitalization. Prognosis for regaining the ability to walk is good, with 64% of those initially dependent in walking regaining independence by three months. However, many gait abnormalities persist.
Reduced hip, knee and ankle excursions during swing are among the persistent gait abnormalities contributing to poor or inefficient limb clearance. This is generally referred to as "foot drop", since the foot drops or drags along the ground during the swing phase. Swing phase abnormalities can result in decreased velocity, limited endurance and an increased risk for falls. These factors can limit mobility and independence in the community. Therefore, intervention is warranted.
The conventional approach to address the poor swing limb function, specifically, insufficient ankle dorsiflexion, is the prescription of an ankle-foot orthosis (AFO). An AFO commonly limits ankle plantarflexion to enhance limb clearance during swing. An alternative approach is to stimulate the ankle dorsiflexors electrically during swing phase to reproduce motion, which can no longer be performed volitionally.
The WalkAide is a new foot drop stimulator. This small, self-contained device attaches to the leg below the knee. The WalkAide contains a number of patented features, including a tilt sensor that measures the orientation of the leg with respect to the vertical. When the leg is tilted back at the end of stance, stimulation of the common peroneal nerve is initiated. This produces flexion of the ankle and other joints (if a flexion reflex is elicited) so that the leg can clear the ground during swing. When the leg is tilted forward at the end of swing phase, the stimulus is terminated. The electrodes attach to the inside of a cuff that is molded to the leg for reproducible positioning from day to day. The device is also designed so that all operations can be done with a single hand, since hemiparesis may prevent the subject from using the other hand. Because of its enhanced features, the WalkAide is anticipated to increase walking speed and improve the quality of life.
- WalkAide Device
Intervention Desc: Arm 1 - Subjects wear WalkAide for 6 weeks then cross over to AFO wear for 6 weeks ARM 1: Kind: Experimental Label: WalkAide Description: Subjects wear WalkAide for 6 weeks then cross over to AFO wear for 6 weeks ARM 2: Kind: Experimental Label: Ankle Foot Orthosis Description: Subjects wear AFO for 6 weeks then cross over to WalkAide wear for 6 weeks
- WalkAide, AFO, Crossover Device
Intervention Desc: WalAide functional elctrical stimulation or Ankle Foot Orthosis worn daily during assigned phase of study ARM 1: Kind: Experimental Label: WalkAide ARM 2: Kind: Experimental Label: Ankle Foot Orthosis ARM 3: Kind: Experimental Label: Crossover
- AFO Device
Intervention Desc: Arm 3 - Subjects wear AFO for entire 12 weeks with no crossover ARM 1: Kind: Experimental Label: WalkAide Description: Subjects wear WalkAide for 6 weeks then cross over to AFO wear for 6 weeks ARM 2: Kind: Experimental Label: Ankle Foot Orthosis Description: Subjects wear AFO for 6 weeks then cross over to WalkAide wear for 6 weeks ARM 3: Kind: Experimental Label: No Crossover Description: Subjects wear AFO for entire 12 weeks with no crossover
- Allocation: Randomized
- Masking: Open Label
- Purpose: Treatment
- Endpoint: Efficacy Study
- Intervention: Crossover Assignment
|Type||Measure||Time Frame||Safety Issue|
|Primary||Use of a foot drop stimulator will significantly increase the speed of walking compared to each subjects preferred method of walking without stimulation.|
|Primary||Use of a foot drop stimulator will decrease the physiological cost index (PCI) compared to each subject's preferred method of walking without stimulation.|
|Secondary||Subjects wills score higher on a variety of functional walking and quality of life tests while using the WalkAide.|
|Primary||Figure 8 Walking Speed Before and After Intervention.||baseline, 6, 6.2 and 12 weeks||No|
|Primary||Physiological Cost Index Before and After Intervention.||baseline, 6, 6.2 and 12 weeks||No|
|Primary||10 Meter Walking Speed Before and After Intervention.||baseline, 6, 6.2 and 12 weeks||No|
|Secondary||Number of Subjects Who Preferred Use of WalkAide Over the Use of AFO||12 weeks||No|