Variable Friction Shoe for Stroke

Overseen By Jennifer Bartloff, DPT, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Shirley Ryan AbilityLab

Disqualifiers: Morbid obesity, Cardiac conditions, Seizures, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 16

50 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new type of shoe called the Variable Friction Shoe (also known as the Cadense Adaptive Shoe or iStride Device) to assist individuals with foot drop after a stroke. Foot drop makes lifting the front part of the foot difficult, leading to walking challenges. The trial compares the new shoe to traditional ankle foot orthosis (AFO) training to determine which is more effective in an at-home setting. Individuals who had a stroke at least three months ago, use or could use an AFO, and can walk at least 10 meters with or without assistance might be suitable candidates. As an unphased trial, this study provides a unique opportunity to explore innovative solutions for improving mobility after a stroke.

Do I need to stop my current medications for the trial?

The trial does not specify that you need to stop your current medications, but it requires that there be no expected change in medications for at least 3 months. This suggests you should continue your current medications without changes.

What prior data suggests that the Variable Friction Shoe is safe for foot drop therapy?

Research has shown that the Variable Friction Shoe (VF shoe) has been tested on individuals with conditions such as multiple sclerosis, brain tumor recovery, and cerebral palsy. In these cases, the VF shoe performed well and received positive feedback. No serious side effects have been reported, indicating a favorable safety profile.

This study is labeled as "Not Applicable" for trial phase, meaning the VF shoe is a device, not a drug, and does not undergo the same testing phases as medications. However, the lack of major safety issues in previous tests offers some reassurance about its use. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Variable Friction Shoe as a potential game-changer for stroke rehabilitation. Unlike traditional approaches like Ankle Foot Orthoses (AFOs), which provide static support, the Variable Friction Shoe introduces dynamic adjustments to friction, encouraging more natural walking patterns and improving balance. This innovative feature could lead to better mobility and independence for stroke survivors by promoting more effective muscle engagement and adaptation.

What evidence suggests that the Variable Friction Shoe is effective for foot drop after stroke?

This trial will compare the effectiveness of the Variable Friction Shoe with Ankle Foot Orthosis (AFO) training for stroke recovery. Studies have shown that the Variable Friction Shoe can improve walking in people with foot drop after a stroke. Research indicates that this shoe can increase walking speed and balance between steps in just one week. Tests on individuals with conditions like multiple sclerosis and cerebral palsy have shown promising results in enhancing movement. The shoe is designed to be affordable and easy to use at home, making it accessible for many. These findings suggest it could be a valuable tool for stroke recovery. ^{1 6 7 8 9}

Who Is on the Research Team?

Arun Jayaraman, PT, PhD

Principal Investigator

Shirley Ryan AbilityLab

Are You a Good Fit for This Trial?

This trial is for adults over 18 who had a stroke between 3 months to a year ago and may need an ankle foot orthosis (AFO). They should be medically stable, not expecting medication changes soon, able to walk at least 10 meters with or without help, and hear the VF shoe click.

Inclusion Criteria

I had a stroke between 3 months and 1 year ago.

Medically stable as determined by physician medical clearance

My medications will stay the same for the next 3 months.

Exclusion Criteria

My BMI is over 40.

Pregnant women (status determined by self-reporting)

I have fallen more than once a week before having a stroke.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline

Baseline assessments and initial fitting of the Variable Friction Shoe or Ankle Foot Orthosis

1 week

Treatment Phase 1

Participants undergo 12 weeks of training with either the Variable Friction Shoe or Ankle Foot Orthosis

12 weeks

8 visits (in-person)

Washout

A 2-week washout period between treatment phases

2 weeks

Treatment Phase 2

Participants undergo 12 weeks of training with the alternate device (Variable Friction Shoe or Ankle Foot Orthosis)

12 weeks

8 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Variable Friction Shoe

Trial Overview The study tests a low-cost Variable Friction Shoe (VF shoe) against standard AFO training for managing foot drop in stroke survivors. Participants will use these devices at home to see which helps more with walking.

How Is the Trial Designed?

Group I: Arm BA: Ankle Foot Orthosis (AFO) Training, Variable Friction Shoe Training Experimental Treatment 2 Interventions

Baseline (T0), 12 weeks AFO Training, Follow-up (T1), 2-week washout, Follow-up (T2), 12 weeks Variable Friction Shoe Training, Follow-up (T3)

Group II: Arm AB: Variable Friction Shoe Training, AFO Training Experimental Treatment 2 Interventions

Baseline (T0), 12 weeks Variable Friction Shoe Training, Follow-up (T1), 2-week washout, Follow-up (T2), 12 weeks AFO Training, Follow-up (T3)

Variable Friction Shoe is already approved in United States for the following indications:

Approved in United States as Variable Friction Shoe for:

• Foot drop in stroke patients

Who Is Running the Clinical Trial?

Shirley Ryan AbilityLab

Lead Sponsor

Trials

212

Recruited

17,900+

University of California, Santa Barbara

Collaborator

Trials

33

Recruited

3,100+

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Collaborator

Trials

2,103

Recruited

2,760,000+

Published Research Related to This Trial

Shoe modifications and foot orthoses are effective nonsurgical treatments for various foot and ankle conditions, improving gait and increasing mobility in patients with diabetes, arthritis, and other pathologies.

Custom orthoses come in four main types, each designed to provide specific benefits such as cushioning, support, and protection, making them versatile tools for both treatment and prevention of foot-related issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Shoe modification and the use of orthoses in the treatment of foot and ankle pathology. Janisse, DJ., Janisse, E.[2019]

A study involving 50 people with diabetes at high risk for foot ulceration revealed a strong demand for custom-made indoor footwear, with 82% expressing a need for it and 66% believing it would improve their adherence to wearing appropriate footwear.

The newly designed indoor footwear matched the pressure relief of regular custom-made options while being lighter, easier to put on, and more cost-effective, indicating a successful approach to enhancing usability for at-risk individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Users' needs and expectations and the design of a new custom-made indoor footwear solution for people with diabetes at risk of foot ulceration. Keukenkamp, R., van Netten, JJ., Busch-Westbroek, TE., et al.[2023]

In a study evaluating three types of anti-slip devices on slippery surfaces, the heel device was found to be the safest and provided the best balance for users, especially on uncovered ice and snow.

Participants reported that the heel device was the quickest to put on, making it a practical choice for preventing slips and falls, while all devices were generally perceived to have good stability and foothold.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Assessment of anti-slip devices from healthy individuals in different ages walking on slippery surfaces. Gard, G., Berggård, G.[2019]

Older adults often wear ill-fitting shoes due to changes in foot shape and pain, which can lead to discomfort and reduced mobility.

The review identified key design elements for safe and comfortable shoes for older adults, including proper anatomical fit, a well-fitting toe box, limited heel height, and a firm insole, highlighting the need for shoe designs tailored to the unique needs of older individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Shoe design for older adults: Evidence from a systematic review on the elements of optimal footwear. Jellema, AH., Huysmans, T., Hartholt, K., et al.[2019]

In a study involving 32 midgait steps, removable walking casts were found to be as effective or even more effective than total contact casts in reducing peak plantar foot pressures at neuropathic ulcer sites in diabetic patients.

Half-shoes were the third most effective option, while accommodative dressings and rigid-soled postoperative shoes were less effective in alleviating pressure at ulcer sites.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

1997 William J. Stickel Bronze Award. Comparison of strategies for reducing pressure at the site of neuropathic ulcers. Fleischli, JG., Lavery, LA., Vela, SA., et al.[2007]

The study found that a rocker sole shoe with a plastizote insert significantly reduces peak plantar pressures in patients with peripheral neuropathy, achieving a 50% reduction at the metatarsal heads compared to a flat sole shoe without the insert.

This footwear is particularly beneficial for individuals at risk of foot ulcers or those healing from them, although the effectiveness of off-loading varied among individual subjects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Forefoot plantar pressure reduction of off-the-shelf rocker bottom provisional footwear. Kavros, SJ., Van Straaten, MG., Coleman Wood, KA., et al.[2011]

A new plantar pressure control device was developed that uses both visual and auditory feedback to help individuals adjust their walking patterns and reduce the risk of foot ulcers, particularly for those with neuropathy.

In a pilot test with one healthy participant, the device successfully prompted changes in gait without increasing pressure in vulnerable areas, suggesting it could be effective for people with diabetic neuropathy who cannot feel pain.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A real-time plantar pressure feedback device for foot unloading. Femery, VG., Moretto, PG., Hespel, JM., et al.[2019]

Using a 5-degree lateral-wedged insole on the nonparetic side significantly improved weight-bearing symmetry during quiet stance in stroke patients, indicating potential benefits for balance and stability.

While the nonparetic side-wedged insole reduced the load on the paretic knee during walking, the paretic side-wedged insole did not show similar benefits, suggesting that the placement of the wedge is crucial for optimizing gait mechanics in stroke rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Immediate effect of lateral-wedged insole on stance and ambulation after stroke. Chen, CH., Lin, KH., Lu, TW., et al.[2016]

A study evaluated 25 different anti-skid devices in Sweden to determine their effectiveness in preventing slips and falls on various slippery surfaces, including ice and snow.

The 'studs' wholefoot device was found to be the most effective, as it was perceived to provide the best walking safety and balance, making it the top choice for personal use among participants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pedestrians on slippery surfaces during winter--methods to describe the problems and practical tests of anti-skid devices. Gard, G., Lundborg, G.[2019]

In a study involving 30 neuropathic diabetic patients, it was found that a minimum of 12 midgait steps per foot is necessary to obtain valid and reliable in-shoe plantar pressure data when evaluating therapeutic footwear.

For each foot region and parameter, only 3 steps were needed for reliable data, but to ensure validity, between 7 and 17 steps were required, highlighting the importance of step count in accurate pressure assessments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Twelve steps per foot are recommended for valid and reliable in-shoe plantar pressure data in neuropathic diabetic patients wearing custom made footwear. Arts, ML., Bus, SA.[2022]

Using static ankle-foot orthoses (AAFOs and PAFOs) with regular shoes significantly improved balance and symmetry in stroke patients, reducing center of pressure (CoP) sway compared to just wearing shoes or being barefoot.

PAFOs were found to be more effective than AAFOs in decreasing CoP sway and enhancing weight shifting, although both types of orthoses negatively affected the natural roll-over shape of the foot during walking.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Static ankle-foot orthosis improves static balance and gait functions in hemiplegic patients after stroke. Chern, JS., Chang, HS., Lung, CW., et al.[2020]

In a study of 32 patients with diabetes and neuropathy, custom-made shoes designed with thick, multi-layer soles resulted in only 9% of patients developing new foot ulcers and 3% experiencing new minor amputations over one year.

The study suggests that these custom shoes may effectively prevent neuropathic ulcerations in high-risk patients, but further research through randomized controlled trials is necessary to confirm their efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Preventing high-risk diabetic foot ulceration by a new method of custom-made shoes in high-risk patients. Prospective study]. Tazi, O., Debure, C.[2022]

A study involving 69 diabetic patients showed that wearing specially designed therapeutic shoes (Podiabetes) significantly reduced the rate of foot ulcer relapses compared to regular shoes, with a relapse rate of 27.7% in the therapeutic group versus 58.3% in the control group after one year.

The use of these therapeutic shoes was statistically associated with a lower risk of ulcer relapses, indicating their effectiveness in preventing complications in diabetic patients with a history of foot ulcerations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Manufactured shoes in the prevention of diabetic foot ulcers. Uccioli, L., Faglia, E., Monticone, G., et al.[2022]

Citations

1. cadense.com cadense.com/pages/research?srsltid=AfmBOooCCAav52GXAYkaKqC4kK-ykMQ-dV0x2q11V4OiT0jMhzGgmDc4

Cadense Research: Improving Mobility with Science- ... In testing with individuals managing conditions like multiple sclerosis, brain tumor recovery, and cerebral palsy, the variable friction shoes showed promising ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT06234124

Characterization and Clinical Trial of a Variable Friction Shoe This study will evaluate a Variable Friction shoe (VF shoe), a new low-cost medical device, for foot drop in an at-home setting. Detailed Description. The ...

3. usf.edu usf.edu/news/2024/stroke-therapy-shoe-invented-at-empowers-patients-recovery.aspx

Stroke therapy shoe invented at USF empowers patients ... New research finds the iStride device improves gait speed and symmetry within one week of use. Its success inspired a stroke patient to fly ...

4. cadense.com cadense.com/collections/shoes-for-stroke-patients?srsltid=AfmBOoq5EV42l_MA4IeUGJAY-1s6_h4S9QNYBPlWUAlqaTVPtSawmlcf

Best Shoes for Stroke Patients After a stroke, recovery can take weeks, months or years. While some patients recover fully from a stroke, others suffer lifelong effects.

5. sralab.org sralab.org/clinical-trials/characterization-and-clinical-trial-variable-friction-shoe-new-paradigm-reduced-constraint-locomotor

Characterization and Clinical Trial of a Variable Friction ... To evaluate the effect of a variable friction shoe on walking in individuals with chronic stroke and foot drop.

6. cadense.com cadense.com/pages/research?srsltid=AfmBOorTxvSAQ_S_HQtE0nKi3MnIF47uXPccCRyyQtFni0RWbX398PSS

Cadense Research: Improving Mobility with Science- ... In testing with individuals managing conditions like multiple sclerosis, brain tumor recovery, and cerebral palsy, the variable friction shoes showed promising ...

7. sralab.org sralab.org/research/labs/max-nader-rto/projects/evaluation-variable-friction-shoe-people-foot-drop-due-stroke

Characterization and Clinical Trial of a Variable Friction ... The purpose of this study is to evaluate the effects of the Variable Friction shoe on gait in individuals with chronic stroke and foot drop.

8. reporter.nih.gov reporter.nih.gov/project-details/9832275

Development of sensory augmentation methods to improve ... The proposed project will develop and conduct initial clinical testing of a novel approach to improve post-stroke gait instability through the augmentation of ...

9. escholarship.org escholarship.org/content/qt00817727/qt00817727.pdf

UC Santa Barbara This measurement helps determine whether the shoe activates its frictional mechanism ap- propriately during gait and verifies that the catch ...