Metabolic Cost of Walking With Passive vs. Powered Prosthetic Knees Among Persons With Limb Loss

February 2, 2026 updated by: Loma Linda University
The purpose of this industry-initiated research study is to test that a powered microprocessor controlled knee improves metabolic function during walking in level and sloped conditions as compared to the subject's physician prescribed prosthesis.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The Procedures include:

Initial Visit:

  1. Informed consent
  2. HIPAA authorization
  3. Determine/verify ambulation potential
  4. Take and record body measurements (height, weight, circumferences)
  5. Activities-Specific Balance Confidence (ABC) scale
  6. L.A.S.A.R. Posture alignment assessment with RxPx

Second Visit

  1. Fit with heartrate monitor and metabolic analyzer mask
  2. Treadmill Test (level-ground) with RxPx
  3. Rest
  4. Treadmill Test (incline) with RxPx
  5. Fit subject with PMPK
  6. L.A.S.A.R. Posture alignment assessment with PMPK
  7. Subject uses PMPK for one week as their primary prosthesis

Third Visit (1 week later)

  1. Fit with heartrate monitor and metabolic analyzer mask
  2. Treadmill Test (level-ground) with PMPK
  3. Rest
  4. Treadmill Test (incline) with PMPK
  5. Activities-Specific Balance Confidence (ABC) scale
  6. Return PMPK and refit of RxPx
  7. Verify alignment with L.A.S.A.R. Posture alignment
  8. Check that all fasteners are secure

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
12

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • Loma Linda, California, United States, 92354
        • Recruiting
        • Loma Linda University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Males and Females with unilateral knee disarticulation or transfemoral (KD/TF) amputation.
  • a body mass greater than 49Kg and less than 117Kg
  • 18-75 years of age
  • Have an ambulation potential of K3 or K4
  • Use a prosthesis daily for walking or sports activities
  • No less than six months of experience with a prosthesis
  • No socket issues or changes in the last six weeks
  • No residual limb pain affecting functional ability.

Exclusion Criteria:

  • Cannot walk at different speeds (MCFL K0-K2)
  • Limb-loss below the knee or through the hip
  • More than one amputation.
  • Uses an assistive device for walking
  • Uncontrolled edema in leg compartments
  • Compromised skin of the residual limb or contralateral foot
  • Are 180 days or less post-amputation
  • Pregnant (self-reported)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Powered Microprocessor-controlled Knee (PMPK)
the "Power Knee" is a commercially available PMPK.
Other: Powered Microprocessor-controlled Knee (PMPK)
A microprocessor-controlled Knee with standardized commercial prosthetic foot
Other Names:
  • Power Knee

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
VO2 uptake - level ground
Time Frame: Change between Baseline Visit (study enrollment) and Visit 2 (3 weeks post-study enrollment)
VO2 uptake during ambulation on a treadmill - level ground
Change between Baseline Visit (study enrollment) and Visit 2 (3 weeks post-study enrollment)
VO2 uptake - incline
Time Frame: Visit 2 (3 weeks post-study enrollment)
VO2 uptake during ambulation on a treadmill - 5 degree incline
Visit 2 (3 weeks post-study enrollment)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Balance confidence
Time Frame: At Baseline Visit (study enrollment)
Activities based balance confidence survey (0-100%) higher score means more balance confidence
At Baseline Visit (study enrollment)
Exertion
Time Frame: Change between Visit 2 (3 weeks post-study enrollment) and Visit 3 (4 weeks post-study enrollment)
Borg Exertion Scale (0-10) with 10 being maximum exertion
Change between Visit 2 (3 weeks post-study enrollment) and Visit 3 (4 weeks post-study enrollment)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Loma Linda University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Össur Iceland ehf

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Michael Davidson, Ph.D., Loma Linda University Health

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 27, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 27, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 14, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 26, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 5220320

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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