Stroke
Conditions
Keywords
walking, balance, exoskeleton
Brief summary
Many people who have experienced a stroke have deficits in their walking balance. The long-term goal of this research is to develop an exoskeleton that can effectively improve walking balance, thus improving functional mobility.
Detailed description
Walking balance is an important component of functional mobility, with post-stroke balance deficits contributing to a fall rate more than double that of age-matched controls. Unfortunately, traditional therapy approaches have not succeeded in addressing balance deficits or reducing fall risk, motivating the use of technology to fill this gap. Although assistive exoskeletons are a promising approach to improve post-stroke mobility, they have generally not been designed to control walking balance and agility. This limitation is a particular concern in the development of devices for people with stroke, as applying forces to "assist" some aspect of walking (including balance) can have unexpected negative effects. The project goal is to investigate the potential of exoskeleton assistance to improve walking balance that will be accepted by people with stroke. To this end, investigators will use a previously developed hip exoskeleton to quantify the effects of assisting gait stabilization.
Interventions
DEVICENo Exoskeleton
The participant will not wear an exoskeleton
DEVICEExoskeleton (zero impedance)
The participant will wear an exoskeleton with zero impedance
DEVICEExoskeleton (low impedance)
The participant will wear an exoskeleton with low joint impedance
DEVICEExoskeleton (medium impedance)
The participant will wear an exoskeleton with medium joint impedance
DEVICEExoskeleton (high impedance)
The participant will wear an exoskeleton with high impedance
Sponsors
Medical University of South Carolina
National Institute on Disability, Independent Living, and Rehabilitation Research
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
All participants will experience the same series of experimental sessions. Within individual sessions, the order in which different exoskeleton conditions are tested will be randomized.
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Evidence of a stroke at least 6 months prior to participation * Evidence of dysfunction of the paretic lower limb (Fugl-Meyer lower extremity motor score \< 34) * At least 21 years of age * Self-reported experience of a fall in the previous year, and/or a fear of falling * Gait speed of at least 0.2 m/s * Ability to walk on a treadmill without a cane or walker * Ability to follow three step commands and communicate with experimenters to answer questions (e.g., regarding their balance confidence) * Provision of informed consent
Exclusion criteria
* Resting blood pressure higher than 220/110 mm Hg * History of unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living * Preexisting neurological orders or dementia * Legal blindness or severe visual impairment * Presence of neglect * History of DVT or pulmonary embolism within 6 months * Uncontrolled diabetes with recent weight loss, diabetic coma, or frequent insulin reactions * Orthopedic injuries or conditions (e.g., joint replacements) in the lower extremities with the potential to alter the gait pattern
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Partial correlation (rSW) between mediolateral pelvis displacement and step width during unperturbed walking | Visit 2, anticipated average 1 week | Mediolateral pelvis displacement will be quantified at the start of each step, and step width will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Partial correlation (rSW) between mediolateral pelvis displacement and step width during speed perturbations | Visit 4, anticipated average 1 year | Mediolateral pelvis displacement will be quantified at the start of each step, and step width will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Partial correlation (rSW) between mediolateral pelvis displacement and step width during vision perturbations | Visit 4, anticipated average 1 year | Mediolateral pelvis displacement will be quantified at the start of each step, and step width will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Partial correlation (rSW) between mediolateral pelvis displacement and step width during mediolateral pull perturbations | Visit 4, anticipated average 1 year | Mediolateral pelvis displacement will be quantified at the start of each step, and step width will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Partial correlation between mediolateral pelvis displacement and mediolateral foot placement during mediolateral pull perturbations | Visit 4, anticipated average 1 year | Mediolateral pelvis displacement will be quantified at the start of each step, and mediolateral foot placement relative to the pelvis will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Average gluteus medius activity during stance phase (surface EMG) with mediolateral pull perturbations | Visit 4, anticipated average 1 year | Average gluteus medius EMG activity will be calculated during the stance phase of walking. This will be calculated for each leg independently. |
| Average gluteus medius activity during swing phase (surface EMG) with mediolateral pull perturbations | Visit 4, anticipated average 1 year | Average gluteus medius EMG activity will be calculated during the swing phase of walking. This will be calculated for each leg independently. |
| Rating of Perceived Stability (RPS) with mediolateral pull perturbations | Visit 4, anticipated average 1 year | This patient reported outcome measure uses a validated scale for participants to self-report their perceived balance while walking. |
| Change in mediolateral foot placement (cm) during pull perturbations relative to unperturbed steps | Visit 4, anticipated average 1 year | The change in mediolateral foot placement locations between steps with and without pull perturbations will be calculated. This will be calculated separately for steps taken with each leg. |
| Partial correlation between mediolateral pelvis displacement and mediolateral foot placement (unperturbed walking) | Visit 2, anticipated average 1 week | Mediolateral pelvis displacement will be quantified at the start of each step, and mediolateral foot placement relative to the pelvis will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Average gluteus medius activity during stance phase (surface EMG) in unperturbed walking | Visit 2, anticipated average 1 week | Average gluteus medius EMG activity will be calculated during the stance phase of walking. This will be calculated for each leg independently. |
| Average gluteus medius activity during swing phase (surface EMG) in unperturbed walking | Visit 2, anticipated average 1 week | Average gluteus medius EMG activity will be calculated during the swing phase of walking. This will be calculated for each leg independently. |
| Rating of Perceived Stability (RPS) during unperturbed walking | Visit 2, anticipated average 1 week | This patient reported outcome measure uses a validated scale for participants to self-report their perceived balance while walking. |
| Partial correlation between mediolateral pelvis displacement and mediolateral foot placement during speed perturbations | Visit 4, anticipated average 1 year | Mediolateral pelvis displacement will be quantified at the start of each step, and mediolateral foot placement relative to the pelvis will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Average gluteus medius activity during stance phase (surface EMG) with speed perturbations | Visit 4, anticipated average 1 year | Average gluteus medius EMG activity will be calculated during the stance phase of walking. This will be calculated for each leg independently. |
| Average gluteus medius activity during swing phase (surface EMG) with speed perturbations | Visit 4, anticipated average 1 year | Average gluteus medius EMG activity will be calculated during the swing phase of walking. This will be calculated for each leg independently. |
| Partial correlation between mediolateral pelvis displacement and mediolateral foot placement during vision perturbations | Visit 4, anticipated average 1 year | Mediolateral pelvis displacement will be quantified at the start of each step, and mediolateral foot placement relative to the pelvis will be calculated at the end of each step. Across all steps, the partial correlation between these two metrics will be calculated - accounting for the mediolateral pelvis velocity. This will be done for steps taken with each leg independently. |
| Rating of Perceived Stability (RPS) with speed perturbations | Visit 4, anticipated average 1 year | This patient reported outcome measure uses a validated scale for participants to self-report their perceived balance while walking. |
| Average gluteus medius activity during stance phase (surface EMG) with vision perturbations | Visit 4, anticipated average 1 year | Average gluteus medius EMG activity will be calculated during the stance phase of walking. This will be calculated for each leg independently. |
| Average gluteus medius activity during swing phase (surface EMG) with vision perturbations | Visit 4, anticipated average 1 year | Average gluteus medius EMG activity will be calculated during the swing phase of walking. This will be calculated for each leg independently. |
| Rating of Perceived Stability (RPS) with vision perturbations | Visit 4, anticipated average 1 year | This patient reported outcome measure uses a validated scale for participants to self-report their perceived balance while walking. |
Countries
United States
Contacts
CONTACTJesse C. Dean, PhD
Outcome results
None listed