Michigan Split-belt Treadmill Training Program to Improve Long-Term Knee Biomechanics After ACL Reconstruction (Mi-SPA)

September 4, 2025 updated by: Riann Palmieri-Smith, University of Michigan

Mi-SPA: Michigan Split-belt Adaptation Paradigm to Improve Knee Loading After Anterior Cruciate Ligament Reconstruction (Aim 3)

The goal of this study is to gather pilot data to help inform a future clinical trial. As such, the investigators will employ a randomized clinical trial design, but data will only be collected on 9 total subjects. Nine subjects will be randomized to 2 split-belt intervention groups (one group where early stance loading is trained and the other where midstance loading is trained) and a placebo group.

The goal of this study is to explore the adaptations in knee loading from a 6-week split-belt training intervention.

The investigators' main question for this aim is:

  1. Does knee loading, measured by the sagittal plane knee moment, change to a greater extent in the split-belt treadmill training groups compared to the placebo group?
  2. Are there differences in training-related knee loading changes between individuals trained in the early stance vs. midstance loading split-belt training?

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

It is commonplace for individuals after anterior cruciate ligament (ACL) reconstruction to shift mechanical demands away from their surgical knee and limb. This manifests as diminished knee moments and vertical ground reaction forces in the ACL limb during everyday tasks (e.g., walking, running, standing, landing, etc.) and persists for as long as 2.5 years after surgery. This pattern of underloading is considered maladaptive, as it has been linked to re-injury and biological markers that are consistent with the development of post-traumatic osteoarthritis that affects over 50% of knees 10-20 years after surgical reconstruction.

Split-belt treadmill training is a gait retraining approach where treadmill belt speeds are decoupled (i.e., one belt is set to move at a faster or slower speed than the other belt) during walking. Split-belt training is based on well-established motor learning principles, such as error-based learning and variability of practice which can lead to locomotor adaptations. In healthy individuals, split-belt treadmill walking significantly increases (from baseline) knee moment impulses in the limb on the slow belt than on the fast belt during the braking and propulsive phases of gait. Split-belt treadmill training has also shown promise in individuals with neurological deficits, resulting in significant improvements in gait biomechanics after training.

To explore the adaptations in loading from a 6-week split-belt training intervention, the investigators will conduct a pilot randomized clinical trial design, but data will only be collected on 9 total subjects. Nine subjects will be randomized to one of 3 groups: 1) early stance split-belt treadmill training, 2) mid-stance split-belt treadmill training, or 3) placebo split-belt treadmill training. The primary outcome, sagittal plane knee moment, will be examined before, midway, & after the 6-weeks of training. Other outcomes, vertical ground reaction force, knee joint contact force, and the Knee Injury and Osteoarthritis Outcome Score, will be measured at the same timepoints. Medial and lateral knee cartilage thickness are additional outcomes that will only be assessed before and after training.

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.
9

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 Contact Backup

  • Name: Riann M Palmieri-Smith, PhD, ATC
  • Phone Number: 734-615-3154
  • Email: riannp@umich.edu

Study Locations

  • United States
    • Michigan
      • Ann Arbor, Michigan, United States, 48176
        • Recruiting
        • University of Michigan
        • Contact:
        • Contact:
        • Principal Investigator:
          • Riann Palmieri-Smith, PhD

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

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • aged 14-45 years
  • suffered an acute, complete ACL rupture as confirmed by MRI and physical exam
  • have undergone ACL reconstruction w autograft within the past 10 months
  • willingness to participate in testing and follow-up as outlined in the protocol
  • English-speaking

Exclusion Criteria:

  • inability to provide written informed consent
  • female subjects who are pregnant or are planning to become pregnant (self-reported)
  • previous ACL injury
  • previous surgery to either knee
  • bony fracture accompanying ACL injury
  • patients who experienced a knee dislocation
  • patients who had their ACL reconstructed with an allograft
  • patients who underwent a multi-ligamentous and/or staged ACL reconstruction

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

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: Early Stance Training
This study arm will complete 6-weeks of a split-belt treadmill training program. The program will require participants to walk on a split-belt treadmill 2 times a week for 20 minutes with the ACL leg walking at 150-170% of 1.1 m/s and the Non-ACL leg walking at 1.1 m/s.
Behavioral: Split-Belt Training
Walking on a split-belt treadmill in which the treadmill belt under the ACL leg will move at a speed faster or slower than the belt under the Non-ACL leg.
Experimental: Mid-Stance Training
This study arm will complete 6-weeks of a split-belt treadmill training program. The program will require participants to walk on a split-belt treadmill 2 times a week for 20 minutes with the ACL leg walking at 30-50% of 1.1 m/s and the Non-ACL leg walking at 1.1 m/s.
Behavioral: Split-Belt Training
Walking on a split-belt treadmill in which the treadmill belt under the ACL leg will move at a speed faster or slower than the belt under the Non-ACL leg.
Placebo Comparator: Placebo Split-Belt Training
This study arm will complete 6-weeks of a split-belt treadmill training program. The program will require participants to walk on a split-belt treadmill 2 times a week for 20 minutes with the ACL leg walking at a speed that is 10% different from 1.1 m/s and the Non-ACL leg walking at 1.1 m/s.
Behavioral: Placebo Split-Belt Training
Walking on a split-belt treadmill in which the belt under the ACL leg will move at a speed that is minimally slower than the other belt.

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
ACL Leg Sagittal Plane Knee Moment
Time Frame: Before training, midway through training (3 weeks), & after training (6 weeks)
Peak Sagittal Plane Knee Moment recorded during walking gait
Before training, midway through training (3 weeks), & after training (6 weeks)

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Non-ACL Leg Sagittal Plane Knee Moment
Time Frame: Before Training, midway through training (3 weeks), & after training (6 weeks)
Peak Sagittal Plane Knee Moment recorded from the Non-ACL leg during walking gait
Before Training, midway through training (3 weeks), & after training (6 weeks)
ACL Leg Vertical Ground Reaction Force
Time Frame: Before Training, midway through training (3 weeks), & after training (6 weeks)
Peak Vertical Ground Reaction Force recorded from the ACL leg during walking gait
Before Training, midway through training (3 weeks), & after training (6 weeks)
Non-ACL Leg Vertical Ground Reaction Force
Time Frame: Before Training, midway through training (3 weeks), & after training (6 weeks)
Peak Vertical Ground Reaction Force recorded from the Non-ACL leg during walking gait
Before Training, midway through training (3 weeks), & after training (6 weeks)
ACL Leg Internal Knee Joint Contact Force
Time Frame: Before Training, midway through training (3 weeks), & after training (6 weeks)
Internal knee joint reaction force for the ACL limb estimated using musculoskeletal modeling
Before Training, midway through training (3 weeks), & after training (6 weeks)
Non-ACL Leg Internal Knee Joint Contact Force
Time Frame: Before Training, midway through training (3 weeks), & after training (6 weeks)
Internal knee joint reaction force for the Non-ACL limb estimated using musculoskeletal modeling
Before Training, midway through training (3 weeks), & after training (6 weeks)
Knee Injury and Osteoarthritis Outcome Score (KOOS)
Time Frame: Before Training, midway through training (3 weeks), & after training (6 weeks)
The KOOS score is a percentage from 0-100, with 0 representing extreme knee problems and 100 representing no knee problems. A higher score indicates fewer knee issues, while a lower score indicates more.
Before Training, midway through training (3 weeks), & after training (6 weeks)
Medial Cartilage Thickness
Time Frame: Before (0 weeks) & after training (6 weeks)
Thickness of the cartilage from the medial femoral trochlea measured using ultrasound
Before (0 weeks) & after training (6 weeks)
Lateral Cartilage Thickness
Time Frame: Before (0 weeks) & after training (6 weeks)
Thickness of the cartilage from the lateral femoral trochlea measured using ultrasound
Before (0 weeks) & after training (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 Michigan

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.
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

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: Chandramouli Krishnan, PT, PhD, University of Michigan
  • Principal Investigator: Riann M Palmieri-Smith, PhD, ATC, University of Michigan

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.
August 13, 2025

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.
August 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.
August 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).
July 26, 2024

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.
July 26, 2024

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.
July 31, 2024

Study Record Updates

Last Update Posted (Estimated)

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.
September 8, 2025

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.
September 4, 2025

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.
August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • HUM00221406_Aim3
  • 1R21AR082643 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified data will be made publicly available via Deep Blue Data which is managed by the University of Michigan.

IPD Sharing Time Frame

We will strive to release data to the repository as rapidly as it is possible to analyze experiments and publish results. Data used in publications will be released at the time of publication.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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