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

Not yet recruiting

Conditions

Intervention / Treatment

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

Interventional

Enrollment (Estimated)

12

Phase

  • 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

  • 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

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
Intervention / Treatment
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

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

University of Florida

Collaborators

Brooks Rehabilitation

Investigators

  • 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)

June 1, 2026

Primary Completion (Estimated)

July 1, 2027

Study Completion (Estimated)

July 1, 2028

Study Registration Dates

First Submitted

May 21, 2026

First Submitted That Met QC Criteria

May 21, 2026

First Posted (Actual)

May 29, 2026

Study Record Updates

Last Update Posted (Actual)

May 29, 2026

Last Update Submitted That Met QC Criteria

May 21, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID 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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