Making lower-limb exoskeletons usable for children and young adults

Toward Ubiquitous Lower Limb Exoskeleton Use in Children and Young Adults: Exploratory Observational Analysis of Novel Robotic Control Strategies

This project will test whether a wearable leg exoskeleton, sometimes paired with electrical muscle stimulation, can help children and young adults with cerebral palsy, muscular dystrophy, spina bifida, or incomplete spinal cord injury walk and move during everyday tasks.

Quick facts

• Study type: Observational
• Enrollment: 23 (estimated)
• Ages: 5 Years to 25 Years
• Sex: All
• Sponsor: National Institutes of Health Clinical Center (CC) (NIH)
• Locations: 1 site (Bethesda, Maryland)
• Trial ID: NCT06998134 on ClinicalTrials.gov

What this trial studies

This exploratory observational study will test three exoskeleton control modes—assist, resist, and interleaved—across multiple functional tasks such as varied-speed treadmill walking, ramps, and obstacle courses. Control parameters will be either fixed or allowed to adapt to the specific activity, and outcomes with the exoskeleton will be compared to baseline performance without it. Optional functional electrical stimulation (FES) may be used with the exoskeleton to augment muscle activation. The primary focus is on acute biomechanical and neuromuscular effects, especially knee extension and knee extensor muscle activity.

Who should consider this trial

Good fit: Children and young adults age 5–25 with muscle weakness and mobility problems from conditions such as cerebral palsy, muscular dystrophy, spina bifida, or incomplete spinal cord injury who can follow study procedures and tolerate brief walking tasks are ideal candidates.

Not a fit: People who are non-ambulatory, have severe fixed joint contractures, complete spinal cord injuries, or cannot travel to the study site are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the work could expand exoskeleton use across everyday settings and improve knee extension and walking ability for young people with lower-limb weakness.

How similar studies have performed: Previous pediatric exoskeleton work has shown promise for flat-surface walking, but translating control modes to multiple everyday tasks is novel and not yet proven.

Eligibility criteria

* INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

* Provision of signed and dated separate informed consent and assent forms for screening purposes. Upon inclusion in the protocol, provision of signed and dated informed consent and assent forms to begin participation in the study will be necessary.
* Stated willingness to comply with all study procedures and availability for the duration of the study, or alternatively, ability to do so based on parent report and physician observation during history and physical examination.
* Age 5 to 25 years old. Importantly, we included young adults (18-25 years old) because longterm outcomes for adults with cerebral palsy include loss of ambulatory ability. While studies of conventional gait training in this population have been conducted, use of exoskeletons in this population is very limited. Given the potential benefit of exoskeletons to reduce knee extension deficiency, it is important to determine whether novel controllers we develop are also tolerated and effective in this age group.
* Either has a gait pathology arising from a diagnosis of CP, MD, SB, or iSCI or has no gait pathology.
* Knee joint range of motion of at least 25 degrees in the sagittal plane (knee extension/flexion) assessed with the hip extended in a supine position. Hamstring contracture as assessed by the straight leg raising test does not limit ability to participate in the study.
* Ankle joint range of motion of at least 15 degrees in the sagittal plane (dorsi-plantarflexion) with the foot in neutral alignment.
* Able to walk at least 10 feet without stopping with or without a walking aid.

EXCLUSION CRITERIA:

An individual who meets any of the following criteria will be excluded from participation in this study:

* Any neurological, musculoskeletal, or cardiorespiratory injury, health condition, or diagnosis other than CP, MD, SB, or iSCI that would affect the ability to walk as directed with the robotic exoskeleton.
* A history of uncontrolled seizures in the past year.
* Pregnancy based on self-reporting. We excluded pregnancy due to confounding factors of pregnancy on gait.
* Adult unable to consent for themselves at screening visit.

Where this trial is running

Bethesda, Maryland

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States (Recruiting)

Study contacts

• Principal investigator: Thomas C Bulea, Ph.D. — National Institutes of Health Clinical Center (CC)
• Study coordinator: Jesse H Matsubara

Conditions Muscle Weakness; Problems Moving Their Arms and Legs; Cerebral Palsy; muscular dystrophy; Spina Bifida; incomplete spinal cord injury