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Lower-limb OrthosesNCT07673328

Enhancing Voluntary Motion in Broad Patient Populations With Modular Powered Orthoses Renewal

A study testing Modular powered orthosis in people with Lower-limb Orthoses and Osteoarthritic Knee Pain, run by University of Michigan at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The overall goal of this project is to establish a novel design and control paradigm for modular, partial-assist powered orthoses (exoskeletons) to enhance voluntary lower-limb motion and manage pain in broad patient populations. Read more about this study

Who is it for?
Ages 18 to 85 yearsHealthy volunteers can take part
What is being tested?
Modular powered orthosis
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
65 participants
Where
1 siteUnited States
Study dates
18 Jul 2025to 31 Mar 2030
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 85 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Inclusion criteria for able-bodied, young participants will be:
  • Aged between 18 to 65 years
  • Weigh less than 300 lbs (due to challenges in bracing heavier participants)
  • BMI < 40 (due to challenges in bracing heavier participants)
  • Inclusion criteria for knee osteoarthritis participants will be:
  • Aged between 30 to 85 years
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  • Medical diagnosis of patellofemoral and tibiofemoral osteoarthritis
  • Patient reported pain ≥ 4 out of 10 during activities of daily life (to avoid floor effects)
  • Weigh less than 300 lbs (due to challenges in bracing heavier participants)
  • BMI < 40 (due to challenges in bracing heavier participants)
  • Ability to walk 6 minutes without assistance from a person (may use walking aid)
  • Ability to ascend/descend ramps and stairs with or without the use of handrails

Who cannot join

  • Exclusion criteria for able-bodied, young adult participants will be:
  • Pregnant (self-report)
  • Any significant neuromuscular or musculoskeletal disorder that would interfere with the study
  • Unable to walk for 20 minutes
  • History of any cardiovascular, vestibular, or visual diseases and/or impairments that may interfere with the study
  • Cognitive deficits that would impair their ability to give informed consent or impair their ability to follow simple instructions during the experiments. Cognitive deficits will be determined by a Mini-Mental State Examination (MMSE) score of <22.
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  • Adults with a known allergy to medical grade tape
  • Exclusion criteria for knee osteoarthritis participants will be:
  • Pregnant (self-report)
  • Any recent lower-extremity fracture (within 6 months)
  • Significant limitation on knee joint range of motion
  • Significant neurological (e.g., stroke) or cardiovascular disorder that may affect the ability to walk
  • Advised by a physician not to walk or exercise
  • Uncontrolled hypertension or diabetes
  • Use of opioids
  • Cognitive deficits or visual impairment that would impair their ability to give informed consent or impair their ability to follow simple instructions during the experiments. Cognitive deficits will be determined by a Mini-Mental State Examination (MMSE) score of <22.
  • Adults with a known allergy to medical grade tape

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Kashvi Pota, MS contact

734-763-1156

kashvip@umich.edu

Robert Gregg, PhD contact

734-763-1156

rdgregg@umich.edu

United States1 site, 1 recruiting
  • Rehab Lab

    Ann Arbor, Michigan, 48109

    Kashvi Pota, 734-763-1156, kashvip@umich.edu

    Robert Gregg, PhD

    Recruiting

Other trials in United States

About this study

The overall goal of this project is to establish a novel design and control paradigm for modular, partial-assist powered orthoses (exoskeletons) to enhance voluntary lower-limb motion and manage pain in broad patient populations. Building upon a previous study period that addressed weakness from advanced age or muscle fatigue, this current period extends the technology to novel powered unloader orthoses designed to manage knee osteoarthritis (OA) pain. The investigators hypothesize that by providing 15-30% of biological joint torque, these motorized devices can reduce muscular contributions to painful loads on the joint's surfaces during activities of daily living (ADLs). The project aims to develop a task-agnostic, neural network-based controller and establish the feasibility of reducing knee pain and muscle effort in individuals with multi-compartment knee osteoarthritis.

Read the detailed description

The overall goal of this project is to develop modular, lower-limb, powered orthoses that fit to user-specific joints and control torque in a manner that enhances voluntary motion and mitigates musculoskeletal pain. Commercial exoskeletons typically use actuation and control methods that force the human user to follow specific, rigid gait patterns. This has prevented emerging wearable robotics from effectively addressing the weakness and pain associated with mild to moderate impairments, such as knee osteoarthritis (OA). These populations require partial, task-agnostic assistance that works harmoniously with their voluntary motion rather than constraining it.

To bridge this gap, this project utilizes a quasi-direct drive actuation paradigm, a high-torque motor combined with a low-ratio transmission, integrated into conventional knee stabilizer and unloader braces. This hardware is uniquely capable of producing large output torques without causing perceptible resistance when backdriven by the human joint. To control the device across various activities of daily living (ADLs) without requiring pre-programmed trajectories, the investigators are developing a neural network-based formulation of "energy shaping" (effectively combining virtual springs, dampers, and gravity/inertia compensation) trained on multi-activity human data.

The specific objectives of this study period are to:

  1. Integrate the modular quasi-direct drive actuator and miniaturized electronics into both a modified knee stabilizer brace and a modified unloader knee brace.
  2. Implement and validate the neural network-based energy shaping controller to provide task-agnostic, biomimetic torque assistance with able-bodied subjects.
  3. Establish the clinical feasibility of this technology in individuals with multi-compartment knee OA.

The investigators hypothesize that the biomimetic torque assistance provided by these motorized braces will significantly reduce quadriceps effort, knee joint moment loads, and subjective pain across ADLs.

Being tested
Modular powered orthosis
Medical subject headings
Osteoarthritis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Modular powered orthosisDevice

    This study will investigate modular, lower-limb, powered orthoses that fit to user-specific weakened joints and control force/torque in a manner that enhances voluntary motion in broad patient populations. The central hypothesis is that high-torque, low-inertia motor systems controlled with energetic objectives will enable modular powered orthoses to partially assist the joints. High-torque electric motors combined with minimal transmissions can be freely rotated (i.e., backdriven) by human joints, allowing the use of an emerging torque control method called energy shaping to reduce the perceived weight/inertia of the body during any motion. By mounting these modular actuators to commercial orthoses, this technology will be easily prescribed/configured by clinicians.

Study groups in NCT07673328
Study groupRoleWhat they receive
ExoskeletonExperimentalExperimental: Exoskeleton Participants in this arm of the study will perform various tasks while wearing the modular powered orthosis
Receives: Device: Modular powered orthosis

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Muscle effort

    Muscle activity will be measured by surface EMG electrodes, and EMG sites will be averaged by flexors and extensors. For each condition (no orthosis vs. powered orthosis), signals will be normalized by their peaks during the no-orthosis condition, and then averaged over cycle, repetitions, and tasks to obtain overall muscle effort (focusing on knee extension for the powered knee orthosis, hip extension and flexion for the powered hip orthosis, and ankle plantarflexion for the powered ankle orthosis).

    Measured: Baseline and through study completion, an average of 2 months

  2. Joint moment load

    Biological torques will be estimated by subtracting the assistive torques from the total joint torques computed via inverse dynamics (using OpenSim). Biological torques will be divided into flexion and extension. For each condition (no orthosis vs. powered orthosis), signals will be normalized by their peaks during the no-orthosis condition, and then averaged over cycle, repetitions, and tasks to obtain overall joint moment load (focusing on knee extension for the powered knee orthosis, hip extension and flexion for the powered hip orthosis, and ankle plantarflexion for the powered ankle orthosis).

    Measured: Baseline and through study completion, an average of 2 months

  3. Pain score

    The Knee Injury and Osteoarthritis Outcome Score (KOOS) will be used to assess perceived pain for a multi-activity circuit test and isolated activity tests.

    The KOOS evaluates both short-term and long-term consequences of knee injury. It holds 42 items in 5 separately scored subscales; Pain, other Symptoms, Function in daily living (ADL), Function in Sport and Recreation (Sport/Rec), and knee-related Quality of Life (QOL). It is an extension of the WOMAC Osteoarthritis Index. A Likert scale is used and all items have five possible answer options scored from 0 (No Problems) to 4 (Extreme Problems) and each of the five scores is calculated as the sum of the items included. Scores are transformed to a 0-100 scale, with zero representing extreme knee problems and 100 representing no knee problems as common in orthopaedic assessment scales and generic measures.

    Measured: Baseline and through study completion, an average of 2 months

Secondary outcomes (5)
  1. 10-meter walk test

    A 10-meter walk test on an overground walkway will assess self-selected walking speed across three conditions: no orthosis, conventional orthosis, and powered orthosis at their preferred assistance level.

    Measured: Baseline and through study completion, an average of 2 months

  2. Joint range of motion

    Joint range of motion for each task will be recorded using optical motion capture and averaged over cycle and repetitions. Motion capture data will be recorded during study visits and used to calculate joint angle, which will then be averaged over gait cycles and activity repetitions to get a range of motion value.

    Measured: Baseline and through study completion, an average of 2 months

  3. Joint compressive forces

    In Aim 3, joint compressive forces for each task will be modeled using OpenSim / inverse dynamics and

    Measured: Baseline and through study completion, an average of 2 months

  4. Difficulty score

    The Knee Injury and Osteoarthritis Outcome Score (KOOS) will be used to assess perceived difficulty for a multi-activity circuit test and isolated activity tests.

    The KOOS evaluates both short-term and long-term consequences of knee injury. It holds 42 items in 5 separately scored subscales; Pain, other Symptoms, Function in daily living (ADL), Function in Sport and Recreation (Sport/Rec), and knee-related Quality of Life (QOL). It is an extension of the WOMAC Osteoarthritis Index. A Likert scale is used and all items have five possible answer options scored from 0 (No Problems) to 4 (Extreme Problems) and each of the five scores is calculated as the sum of the items included. Scores are transformed to a 0-100 scale, with zero representing extreme knee problems and 100 representing no knee problems as common in orthopaedic assessment scales and generic measures.

    Measured: Baseline and through study completion, an average of 2 months

  5. QUEST

    We will administer the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) survey after each orthosis condition to assess comfort and satisfaction with the device.

    The QUEST 2.0 is a highly-validated, 12-item self-report questionnaire designed to measure how satisfied a person is with a wide range of assistive technology. It contains 12 items divided into 2 primary categories: device subscale and services subscale. Participants rate each item using a 5-point Likert scale: 1 = Not satisfied at all, 2 = Not very satisfied, 3 = More or less satisfied, 4 = Quite satisfied, 5 = Very satisfied. To calculate the final metrics, the scores of the items are summed and divided by the total number of valid responses. This yields three separate scores ranging from 1.0 to 5.0: a Device Score, a Services Score, and a Total QUEST Score. Higher scores indicate a better outcome (greater satisfaction with the technology).

    Measured: Baseline and through study completion, an average of 2 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Jun 2026
  2. Study start18 Jul 2025
  3. Primary completion30 Mar 2030 (estimated)
  4. Study completion31 Mar 2030 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
65 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07673328
Sponsor's protocol ID
HUM00201957_Period2
Other IDs
R01EB031166
Status last verified
Sep 2026
First submitted
16 Jun 2026
Last updated
30 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

A study testing Modular powered orthosis in people with Lower-limb Orthoses and Osteoarthritic Knee Pain, run by University of Michigan at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 12 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 30 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Kashvi Pota, MS (734-763-1156, kashvip@umich.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Muscle effort (time frame: Baseline and through study completion, an average of 2 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2026.

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