Bio Leg: Advancing Mobility (BAM)

May 21, 2026 updated by: University of Florida

Adaptive Mobility Technology: A Comparative Study of C-Leg and Bio Leg

Following transfemoral amputation, regaining functional mobility, particularly the ability to navigate curbs, ramps, long distances, and the ability to stand is challenging and often unattainable. Use of advanced prosthetic limb technology can dramatically influence mobility outcomes. The purpose of this study is to compare walking function in individuals with transfemoral amputations who are current users of the C-leg (current clinical standard) to function achieved when using the Bio Leg powered micro-processor prosthetic knee.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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

Although microprocessor-controlled knees (MPKs) such as the C-Leg have demonstrated clear benefits over non-microprocessor-controlled prosthetic knees, it remains unclear whether powered knee assistance provides additional advantages in movement quality, metabolic efficiency, and limb loading during walking adaptability tasks.

This study directly addresses this gap by comparing mobility using the Bio Leg to mobility with the C-Leg using outcome measures that reflect real-world mobility challenges.

By generating objective evidence on whether powered knee assistance improves biomechanics, efficiency, and stability beyond that achieved with an established MPK, this study will inform prosthetic prescription, rehabilitation strategies, and payer decision-making. Given the growing population of individuals living with transfemoral amputation, identifying technologies that support safe, efficient, and confident mobility has important implications for community participation, long-term musculoskeletal health, and quality of life.

This study uses a within-subject repeated-measures design in which each participant is assessed under two conditions: current prosthesis and the Bio Leg prosthesis. All primary and secondary outcomes will be analyzed as within-participant differences, with each participant serving as their own control.

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.
  • Name: Emily J Fox, PT, DPT, MHS, PhD
  • Phone Number: 904-742-2500
  • Email: ejfox@phhp.ufl.edu

Study Contact Backup

Study Locations

  • United States
    • Florida
      • Jacksonville, Florida, United States, 32216
        • Brooks Rehabilitation

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:

  • Adults 40 to 70 years of age
  • Unilateral transfemoral amputation > 1 year
  • K3 or K4 ambulator and able to walk with no greater assistances than a single point cane
  • Current microprocessor-controlled prosthesis (C-leg) user with > 6 months experience and able to walk without a device of using a single point cane
  • Able to give informed consent

Exclusion Criteria:

  • Severe cardiovascular condition or other disease limiting study participation
  • Skin lesions or wounds, acute or unstable fracture, diagnosis of osteoarthritis or bone impairments affecting safe participation in walking activities
  • Residual limb dysfunction (i.e. joint contracture) limiting mobility or study participation
  • Pain that limits walking of participation in walking activities
  • Current participation in rehabilitation to address walking function

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: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Crossover 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.
No Intervention: C-Leg
The first assessment will involve testing the participant with their current C-leg microprocessor prosthesis.
Experimental: Bio Leg
After the Bio Leg fitting, the participant will exclusively wear the Bio Leg knee component for an acclimation period that will be a minimum of 4 weeks and up to 6 depending on participant's schedule and comfort/ease of using the device. Each participant will complete a minimum of 2 and up to 4 physical therapy sessions during the acclimation period. These physical therapy sessions will involve standard physical therapy training for use of a prosthetic limb after amputation. Following the acclimation period, the participant will complete the second assessment, which will mirror the first assessment.
Device: Bio-Leg
After completing biomechanics and clinical testing at Pre Assessment with their C-Leg, participants will be fitted with a Bio-Leg prosthesis at the prosthetist clinic. The participant will train and use the Bio-Leg prosthesis during a 4-6 week acclimation period. The participant will then complete the same biomechanics and clinical testing at Post Assessment.

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
Change in 6-Minute Walk Test (6MWT)
Time Frame: Baseline, 4-6 weeks
The distance that a patient should walk based on their height, weight, age, and gender. Performance assessment of walking endurance for 6 minutes. An increase in the number of meters walked during this assessment reflects an improvement in walking endurance.
Baseline, 4-6 weeks
Change in Interlimb Symmetry (Ground Reaction Forces)
Time Frame: Baseline, 4-6 weeks
A direct measure of vertical ground reaction forces during the rising phase of a sit-to-stand task (measured in Newtons) using standard force plates embedded in the floor. Increased symmetry in ground reaction forces between the lower limbs reflects improved equalization of weight distribution between the limbs.
Baseline, 4-6 weeks
Change in Metabolic Efficiency (O2/kg/m)
Time Frame: Baseline, 4-6 weeks
A direct measure assessed during the six-minute walk test. Metabolic efficiency is determined by the energy cost of transport, defined as oxygen consumption per unit body weight and distance walked (O₂/kg/m), which accounts for the individual's weight and walking speed. Improved metabolic efficiency reflects enhanced oxygen delivery and utilization during walking.
Baseline, 4-6 weeks

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.
University of Florida

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.
Brooks Rehabilitation

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: Emily J Fox, PT, DPT, MHS, PhD, University of Florida & Brooks Rehabilitation

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 (Estimated)

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.
June 1, 2026

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.
July 1, 2027

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.
July 1, 2028

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).
May 21, 2026

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.
May 21, 2026

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.
May 29, 2026

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.
May 29, 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.
May 21, 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.
May 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.
  • IRB202600203

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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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