Michigan Split-belt Treadmill Training Program to Improve Acute Knee Biomechanics After ACL Reconstruction

NCT ID: NCT06529679

Last Updated: 2025-11-06

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

30 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-10-29

Study Completion Date

2025-12-31

Brief Summary

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The goal of this study is to determine short-term adaptations (aftereffects) in knee loading after a 20-minute split-belt treadmill training session in patients with ACL reconstruction.

Our main question for this aim are:

1. Are training-mediated aftereffects in the knee joint moment greater for tied-belt walking or split-belt walking?
2. Are training-mediated aftereffects in the knee joint moment different between subjects who train early stance knee loading versus subjects who train mid-stance knee loading?

Detailed Description

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Knee and limb underloading are ubiquitous after anterior cruciate ligament (ACL) reconstruction and fails to resolve with the standard of care rehabilitation. This underloading behavior is clinically concerning and considered maladaptive, as it affects patient function, has been linked to risk for re-injury, and appears to be a precursor for post-traumatic knee osteoarthritis that affects upwards of 50% of patients who undergo an ACL 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 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.

The aim of this project is to determine short-term adaptations (aftereffects) in knee loading after a 20-minute split-belt treadmill training session in individuals with anterior cruciate ligament (ACL) reconstruction. Individuals \~6-10 months after ACL reconstruction will be randomly assigned to 1 of 2 groups and each group will complete a split-belt and tied-belt session. One group will train the early stance knee moment with split-belt walking, while the other group will train the mid-stance knee moment with split-belt walking. Both groups will also complete a tied-belt session. Bilateral knee loading will be quantified using peak knee moments before training (10 min), during training (20 min), and after training (10 min). The investigators hypothesize that the training-mediated aftereffects (i.e., loading after training) will be significantly higher in the split-belt condition than in the tied-belt control condition. The investigators also hypothesize that early stance split-belt training will lead to training-mediated aftereffects for the early stance moment only, while mid-stance training will only result in aftereffects for the mid-stance knee moment.

Conditions

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ACL ACL Injury

Keywords

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Biomechanics Knee loading Split-belt Asymmetric Walking

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Early Stance Training

This study arm will complete both a 20-minute split-belt \& tied-belt session. During the split-belt session, the ACL limb will walk at a faster speed (150-170% of 1.1 m/s) than the non-ACL limb (1.1 m/s). During the tied-belt session both limbs will walk at the same speed which will be set to match the faster speed of the ACL leg from the split-belt training day.

Group Type EXPERIMENTAL

Split-belt Training

Intervention Type BEHAVIORAL

Walking on a split-belt treadmill in which the speed of one belt will be different (move faster or slower) than the speed of the other belt.

Tied-Belt Training

Intervention Type BEHAVIORAL

Walking on a split-belt treadmill in which the speed of both belts is the same.

Mid-Stance Training

This study arm will complete both a 20-minute split-belt \& tied-belt session. During the split-belt session, the ACL limb will walk at a slower speed (30-50% of 1.1 m/s) than the non-ACL limb (1.1 m/s). During the tied-belt session both limbs will walk at the same speed which will be set to match the slower speed of the ACL leg from the split-belt training day.

Group Type EXPERIMENTAL

Split-belt Training

Intervention Type BEHAVIORAL

Walking on a split-belt treadmill in which the speed of one belt will be different (move faster or slower) than the speed of the other belt.

Tied-Belt Training

Intervention Type BEHAVIORAL

Walking on a split-belt treadmill in which the speed of both belts is the same.

Interventions

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Split-belt Training

Walking on a split-belt treadmill in which the speed of one belt will be different (move faster or slower) than the speed of the other belt.

Intervention Type BEHAVIORAL

Tied-Belt Training

Walking on a split-belt treadmill in which the speed of both belts is the same.

Intervention Type BEHAVIORAL

Eligibility Criteria

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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
Minimum Eligible Age

14 Years

Maximum Eligible Age

45 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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

NIH

Sponsor Role collaborator

University of Michigan

OTHER

Sponsor Role lead

Responsible Party

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Riann Palmieri-Smith

Professor School of Kinesiology

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Riann M Palmieri-Smith, PhD, ATC

Role: PRINCIPAL_INVESTIGATOR

University of Michigan

Chandramouli Krishnan, PT, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Michigan

Locations

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University of Michigan

Ann Arbor, Michigan, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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Alexa Johnson, PhD

Role: CONTACT

Phone: 734-615-1297

Email: [email protected]

Riann M Palmieri-Smith, PhD, ATC

Role: CONTACT

Phone: 734-615-3154

Email: [email protected]

Facility Contacts

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Riann Palmieri-Smith, PhD

Role: primary

Other Identifiers

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1R21AR082643

Identifier Type: NIH

Identifier Source: secondary_id

View Link

HUM00221406_Aim2

Identifier Type: -

Identifier Source: org_study_id