Effect of Altered Mechanical Loading in ACLR

Not Applicable

Completed

• Conditions: Anterior Cruciate Ligament Reconstruction
• Interventions: Other: Real-Time Biofeedback

• Registration Number: NCT03035994
• Lead Sponsor: University of North Carolina, Chapel Hill

Brief Summary

Altered loading is a causative factor for the development of knee osteoarthritis following anterior cruciate ligament reconstruction (ACLR), and real-time biofeedback may be an effective intervention to manipulate altered mechanical loading about the knee. The purpose of this study is to 1) determine if ACLR participants are able to acquire and retain various loading patterns using real-time biofeedback, 2) determine the effect of altered loading on lower extremity biomechanics during walking gait, and 3) determine the effect of altered loading on biochemical markers of collagen turnover and inflammation during walking gait.

Detailed Description

Participants will attend 4 testing sessions. Lower extremity biomechanical outcomes and blood samples will be taken before and following the participant walking at a self-selected speed for 20 minutes. During the 20 minutes of treadmill walking real-time biofeedback will be displayed in an attempt to alter mechanical loading. Participants will complete a control, overloading, under-loading, average loading testing session. Order of loading condition will be randomized.

Study Timeline

• Study Start: 2016-07
• Study First Submitted: 2017-01-22
• Study First Submitted QC: 2017-01-26
• Study First Posted: 2017-01-30
• Primary Completion: 2017-02
• Status Verified: 2017-04
• Study Completion: 2017-04
• Last Update Submitted: 2017-04-17
• Last Update Posted: 2017-04-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• Have a history of a primary, unilateral ACLR using either a hamstring or patellar tendon autograft, cleared by a physical for full return to physical activity with no limitations, and participate in at least 30 minutes of physical activity 3 times per week

Exclusion Criteria

• History of injury to either leg, other than ACLR (e.g. ankle sprain, muscle strain), within 6 months prior to participation in the study, history of lower extremity surgery other than ACLR, history of osteoarthritis or current symptoms related to knee osteoarthritis (e.g. pain, swelling, stiffness), currently pregnant, or planning to become pregnant while enrolled in the study, cardiovascular restrictions that limit the participant's ability to participate in physical activity.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Overloading	Real-Time Biofeedback	Participants will walk on a force-instrumented treadmill for 20 minutes and will be provided visual biofeedback consisting of bilateral vertical ground reaction force. A target will be placed at 10% greater than the participant's baseline vertical ground reaction force. Participants will be asked to alter their walking gait in an attempt to reach the target line with each step.
Underloading	Real-Time Biofeedback	Participants will walk on a force-instrumented treadmill for 20 minutes and will be provided visual biofeedback consisting of bilateral vertical ground reaction force. A target will be placed at 10% lower than the participant's baseline vertical ground reaction force. Participants will be asked to alter their walking gait in an attempt to reach the target line with each step.
Average	Real-Time Biofeedback	Participants will walk on a force-instrumented treadmill for 20 minutes and will be provided visual biofeedback consisting of bilateral vertical ground reaction force. A target will be placed at the average of each participant's baseline vertical ground reaction force between limbs. Participants will be asked to alter their walking gait in an attempt to reach the target line with each step.

Primary Outcome Measures

Name	Time	Method
Difference in joint loading as measured in peak vertical ground reaction force normalized to body weight (xBW) between loading conditions	Change in joint loading over 20 minute intervention
Difference in cartilage turnover as measured in serum concentration of cartilage oligomeric matrix protein (pg/mL) between loading conditions	Chance in cartilage turnover over 20 minute intervention
Difference in acquisition as measured in root mean square error (RMSE) between loading conditions	Change in acquisition over 20 minute intervention