Stroke
Conditions
Keywords
electrical stimulation
Brief summary
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.
Detailed description
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.
Interventions
Sponsors
Innovative Neurotronics
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Adults aged 18 years or older 2. Diagnosed with cerebrovascular accident (CVA) within the last 365 days 3. Inadequate dorsiflexion during the swing phase of gait, resulting in inadequate limb clearance 4. Medically stable for six months prior to the most recent episode of stroke resulting in hemiplegia or hemiparesis with foot drop 5. Medical clearance by the attending physician to participate in the study 6. Expectation that current medication can be maintained without drastic change for at least six months 7. Adequate stability at the ankle during stance (with stimulation) 8. Adequate cognitive and communication function to give informed consent, understand the training instructions, use the device and give adequate feedback 9. Ability to ambulate with or without an assistive device (or assistance) at least 10 meters
Exclusion criteria
1. Lower motor neuron injury with inadequate response to stimulation 2. History of falls greater than once a week prior to the CVA 3. Severe cardiac disease such as myocardial infarction, congestive heart failure or a demand pacemaker (or other electrical stimulator) 4. Fixed ankle contractures of five degrees of plantarflexion with knee extended 5. Moderate to normal ambulation velocity (greater than 1.2 m/s) 6. Unable to operate the device safely by self and caregiver assistance not available 7. Need for an AFO for stance control of the foot, ankle and/or knee 8. Comorbid conditions unlikely to survive one year 9. Pre-existing history of seizure disorder prior to most recent episode of CVA 10. Pre-existing pathology resulting in a significant disruption in alignment or function of the lower extremity 11. Morbid obesity that limits the subject's response to stimulation due to adipose tissue \[BMI \> 40\] 12. Excessive dysesthetic pain secondary to neurological involvement 13. Severe hypertonicity resulting in the need for more involved orthotic strategies or pharmacological interventions (e.g. Botox)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Figure 8 Walking Speed Before and After Intervention. | baseline, 6, 6.2 and 12 weeks | Subjects walked a 10 meter Figure 8 pattern for four minutes at fastest safe speed. This was measured under two conditions: On condition - the WA turned on or the AFO worn by the subject; off condition - The WA turned off or the AFO not worn by the subject. The endpoints were analyzed at 6, and 12 weeks |
| Physiological Cost Index Before and After Intervention. | baseline, 6, 6.2 and 12 weeks | PCI is the difference between resting heart rate and active heart rate during walking, divided by average walking speed. This was measured under two conditions: On condition - the WA turned on or the AFO worn by the subject; off condition - The WA turned off or the AFO not worn by the subject. The endpoints were analyzed at 6, and 12 weeks |
| 10 Meter Walking Speed Before and After Intervention. | baseline, 6, 6.2 and 12 weeks | Subjects walked 10 meters at their fastest safe speed. This was measured under two conditions: On condition - the WA turned on or the AFO worn by the subject; off condition - The WA turned off or the AFO not worn by the subject. The endpoints were analyzed at 6, and 12 weeks |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Subjects Who Preferred Use of WalkAide Over the Use of AFO | 12 weeks | Subjects in Arm 1 or 2 (who used both devices) were given the option to continue using WalkAide or AFO for additional 12 weeks, their preference was recorded along with reasons for preference |
Countries
United States
Participant flow
Recruitment details
Recruitment took place between May 2005 and December 2008 at 9 Rehabilitation centers in the USA.
Participants by arm
| Arm | Count |
|---|---|
| Arm 1: WalkAide Subjects started with the WalkAide and crossed over to the AFO after six weeks. | 43 |
| Arm 2: Ankle Foot Orthosis Subjects started with the AFO and crossed over to the WalkAide after six weeks. | 39 |
| Arm 3: No Crossover Subjects completed the entire 12 weeks period with the AFO, no crossover occurred. | 30 |
| Total | 112 |
Baseline characteristics
| Characteristic | Arm 1: WalkAide | Arm 2: Ankle Foot Orthosis | Arm 3: No Crossover | Total |
|---|---|---|---|---|
| Age Continuous | 57.1 years STANDARD_DEVIATION 12.9 | 55.6 years STANDARD_DEVIATION 11.9 | 58.8 years STANDARD_DEVIATION 9.8 | 57.0 years STANDARD_DEVIATION 11.8 |
| Chronicity | 6.4 years STANDARD_DEVIATION 3.8 | 6.9 years STANDARD_DEVIATION 3.2 | 5.8 years STANDARD_DEVIATION 3.7 | 6.4 years STANDARD_DEVIATION 3.6 |
| Sex: Female, Male Female | 7 Participants | 16 Participants | 12 Participants | 35 Participants |
| Sex: Female, Male Male | 36 Participants | 23 Participants | 18 Participants | 77 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 7 / 43 | 5 / 39 | 1 / 30 |
| serious Total, serious adverse events | 1 / 43 | 1 / 39 | 1 / 30 |
Outcome results
Primary
10 Meter Walking Speed Before and After Intervention.
Subjects walked 10 meters at their fastest safe speed. This was measured under two conditions: On condition - the WA turned on or the AFO worn by the subject; off condition - The WA turned off or the AFO not worn by the subject. The endpoints were analyzed at 6, and 12 weeks
Time frame: baseline, 6, 6.2 and 12 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 0 on condition | .524 meters/second | Standard Deviation 0.253 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 0 off condition | .457 meters/second | Standard Deviation 0.245 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 6 on condition | .625 meters/second | Standard Deviation 0.309 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 12 on condition | .730 meters/second | Standard Deviation 0.369 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 6 off condition | .575 meters/second | Standard Deviation 0.291 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 6.2 off condition | .591 meters/second | Standard Deviation 0.304 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 6.2 on condition | .645 meters/second | Standard Deviation 0.313 |
| Subjects Who Used Both WA and AFO | 10 Meter Walking Speed Before and After Intervention. | Week 12 off condition | .641 meters/second | Standard Deviation 0.349 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 6 off condition | .489 meters/second | Standard Deviation 0.233 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 12 off condition | .564 meters/second | Standard Deviation 0.264 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 0 off condition | .415 meters/second | Standard Deviation 0.22 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 6.2 on condition | .508 meters/second | Standard Deviation 0.223 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 12 on condition | .596 meters/second | Standard Deviation 0.278 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 0 on condition | .472 meters/second | Standard Deviation 0.246 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 6 on condition | .568 meters/second | Standard Deviation 0.261 |
| Arm 2: Ankle Foot Orthosis | 10 Meter Walking Speed Before and After Intervention. | Week 6.2 off condition | .486 meters/second | Standard Deviation 0.229 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 12 on condition | .546 meters/second | Standard Deviation 0.326 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 0 off condition | .361 meters/second | Standard Deviation 0.264 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 6 off condition | .428 meters/second | Standard Deviation 0.286 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 0 on condition | .438 meters/second | Standard Deviation 0.286 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 6 on condition | .500 meters/second | Standard Deviation 0.308 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 6.2 off condition | .428 meters/second | Standard Deviation 0.286 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 12 off condition | .477 meters/second | Standard Deviation 0.296 |
| Arm 3: No Crossover | 10 Meter Walking Speed Before and After Intervention. | Week 6.2 on condition | .500 meters/second | Standard Deviation 0.308 |
Primary
Figure 8 Walking Speed Before and After Intervention.
Subjects walked a 10 meter Figure 8 pattern for four minutes at fastest safe speed. This was measured under two conditions: On condition - the WA turned on or the AFO worn by the subject; off condition - The WA turned off or the AFO not worn by the subject. The endpoints were analyzed at 6, and 12 weeks
Time frame: baseline, 6, 6.2 and 12 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 0 off condition | .337 meters/second | Standard Deviation 0.164 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 6 off condition | .432 meters/second | Standard Deviation 0.207 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 0 on condition | .358 meters/second | Standard Deviation 0.157 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 6 on condition | .456 meters/second | Standard Deviation 0.205 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 6.2 off condition | .446 meters/second | Standard Deviation 0.216 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 12 off condition | .467 meters/second | Standard Deviation 0.233 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 6.2 on condition | .471 meters/second | Standard Deviation 0.219 |
| Subjects Who Used Both WA and AFO | Figure 8 Walking Speed Before and After Intervention. | Week 12 on condition | .520 meters/second | Standard Deviation 0.236 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 0 on condition | .368 meters/second | Standard Deviation 0.186 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 6.2 on condition | .400 meters/second | Standard Deviation 0.153 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 6 on condition | .428 meters/second | Standard Deviation 0.179 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 6.2 off condition | .383 meters/second | Standard Deviation 0.162 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 12 off condition | .420 meters/second | Standard Deviation 0.171 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 0 off condition | .312 meters/second | Standard Deviation 0.151 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 6 off condition | .377 meters/second | Standard Deviation 0.166 |
| Arm 2: Ankle Foot Orthosis | Figure 8 Walking Speed Before and After Intervention. | Week 12 on condition | .436 meters/second | Standard Deviation 0.172 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 0 on condition | .331 meters/second | Standard Deviation 0.203 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 6 off condition | .303 meters/second | Standard Deviation 0.195 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 0 off condition | .261 meters/second | Standard Deviation 0.182 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 6 on condition | .366 meters/second | Standard Deviation 0.205 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 6.2 on condition | .366 meters/second | Standard Deviation 0.205 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 12 off condition | .328 meters/second | Standard Deviation 0.212 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 6.2 off condition | .303 meters/second | Standard Deviation 0.195 |
| Arm 3: No Crossover | Figure 8 Walking Speed Before and After Intervention. | Week 12 on condition | .388 meters/second | Standard Deviation 0.208 |
Primary
Physiological Cost Index Before and After Intervention.
PCI is the difference between resting heart rate and active heart rate during walking, divided by average walking speed. This was measured under two conditions: On condition - the WA turned on or the AFO worn by the subject; off condition - The WA turned off or the AFO not worn by the subject. The endpoints were analyzed at 6, and 12 weeks
Time frame: baseline, 6, 6.2 and 12 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 0 off condition | .957 beats/minute | Standard Deviation 618 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 6 off condition | .824 beats/minute | Standard Deviation 0.446 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 0 on condition | .985 beats/minute | Standard Deviation 0.58 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 6 on condition | .791 beats/minute | Standard Deviation 0.411 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 6.2 off condition | .796 beats/minute | Standard Deviation 0.484 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 12 off condition | .712 beats/minute | Standard Deviation 0.494 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 6.2 on condition | .726 beats/minute | Standard Deviation 0.435 |
| Subjects Who Used Both WA and AFO | Physiological Cost Index Before and After Intervention. | Week 12 on condition | .656 beats/minute | Standard Deviation 0.325 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 0 on condition | .903 beats/minute | Standard Deviation 0.44 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 6.2 on condition | .847 beats/minute | Standard Deviation 0.4 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 6 on condition | .853 beats/minute | Standard Deviation 0.471 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 6.2 off condition | .908 beats/minute | Standard Deviation 0.499 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 12 off condition | .983 beats/minute | Standard Deviation 0.662 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 0 off condition | 1.128 beats/minute | Standard Deviation 0.616 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 6 off condition | .978 beats/minute | Standard Deviation 0.698 |
| Arm 2: Ankle Foot Orthosis | Physiological Cost Index Before and After Intervention. | Week 12 on condition | .972 beats/minute | Standard Deviation 0.694 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 0 on condition | 1.163 beats/minute | Standard Deviation 0.621 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 6 off condition | 1.311 beats/minute | Standard Deviation 0.72 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 0 off condition | 1.486 beats/minute | Standard Deviation 0.753 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 6 on condition | 1.022 beats/minute | Standard Deviation 0.455 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 6.2 on condition | 1.022 beats/minute | Standard Deviation 0.455 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 12 off condition | 1.160 beats/minute | Standard Deviation 0.823 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 6.2 off condition | 1.311 beats/minute | Standard Deviation 0.72 |
| Arm 3: No Crossover | Physiological Cost Index Before and After Intervention. | Week 12 on condition | .892 beats/minute | Standard Deviation 0.481 |
Secondary
Number of Subjects Who Preferred Use of WalkAide Over the Use of AFO
Subjects in Arm 1 or 2 (who used both devices) were given the option to continue using WalkAide or AFO for additional 12 weeks, their preference was recorded along with reasons for preference
Time frame: 12 weeks
Population: per protocol (completers) analysis
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Subjects Who Used Both WA and AFO | Number of Subjects Who Preferred Use of WalkAide Over the Use of AFO | 45 participants |
p-value: <0.001Chi-squared