External Focus of Attention Feedback to Reduce Risk of Non-contact ACL Injury

Knee injuries, especially those to the ACL, are common among physically active people. Preventing these injuries from happening is critical to limiting the long-term pain, disability, and arthritis associated with these injuries. Our study is going to examine new ways to provide feedback about the way people move to determine if these are better at modifying movement patterns to prevent injury than current standard treatments. If you participate, you will be asked to undergo a movement analysis in a research laboratory while you perform tasks such as landing from a box and running and cutting. After this initial assessment, you will be randomly allocated to one of 3 treatment groups. Each treatment group will perform 4 weeks (3x/week) of exercises to change the way people land from a jump. Participants will then report for follow-up movement analysis testing 1- and 4-weeks after completing the intervention.

Study Overview

• Status: Completed
• Conditions: Anterior Cruciate Ligament Injuries
• Intervention / Treatment: Other: Internal focus of attention feedback; Other: Visual internal focus of attention feedback; Other: Auditory external focus of attention feedback

Detailed Description

Despite the popularity of injury prevention programs, anterior cruciate ligament (ACL) injuries continue to occur at a rate of 250,000 per year in the United States. It is believed that 75% of these injuries are preventable, thus alternative strategies to reduce the risk of injury are necessary. One reason current prevention strategies are not wholly successful may be their reliance on internal focus of attention (InFOCUS) feedback, which constrains movement and increases injury risk. Our project will examine an alternative approach, testing two different modes of external focus of attention (ExFOCUS) feedback to remove constrains on the way people move to reduce injury risk. We will also examine cortical activity to determine if there are differences in neuroplasticity that occur following each form of feedback to better understand how each works. Collectively, the knowledge gained from this study will inform the development of programs to reduce injury risk.

Specific Aim 1: Determine ExFOCUS's ability to reduce the risk of noncontact ACL injury by retaining improved biomechanics compared to InFOCUS. Hypothesis 1.1: the combined auditory and visual ExFOCUS groups will demonstrate greater improvements in biomechanics and will retain these improvements 1 month after cessation of the intervention.

Specific Aim 2: Determine differences in the ability of the two modes (visual and auditory) of ExFOCUS to change biomechanics. Hypothesis 2.1: Auditory ExFOCUS feedback will elicit superior results compared to visual ExFOCUS feedback immediately following the intervention. Specific Aim 3: To quantify differences in cortical activity following external focus of attention and internal focus of attention feedback. Hypothesis 3.1: External focus of attention feedback will increase cortical activity in both groups while there will be no changes in cortical activity during internal focus of attention feedback Hypothesis 3.2: Auditory feedback will elicit greater changes in auditory regions of the brain, while visual feedback will elicit greater changes in regions of the brain responsible for processing visual information.

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Charlotte, North Carolina, United States, 28223
      • UNC Charlotte

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• exercise 30+ minutes 3+ days/week

Exclusion Criteria:

• Body mass index >40 kg/m2
• History of lower extremity fracture or surgery to either limb
• History of ACL tear, meniscus, or collateral ligament injury at the knee to either limb
• History of ankle sprains to either limb
• History of musculoskeletal injury sustained in the 6 months prior to enrollment
• History of concussion or neurological disorders that may influence electroencephalography activity
• Visual or hearing impairments that would limit receiving the appropriate feedback
• Inability to comprehend and repeat back directions in English
• Current smoker

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Internal focus of attention feedback; Participants will complete 12 sessions over 3 weeks receiving visual feedback in a mirror of their movement patterns.	Other: Internal focus of attention feedback; Participants will complete 12 sessions over a 3-week period of functional movement retraining while receiving mirror feedback. Participants will be instructed to perform each functional task in a manner that keeps their knee in line with their toes.
Experimental: Visual external focus of attention feedback; Participants will complete 12 sessions over 3 weeks receiving visual feedback of their movement patterns from a laser.	Other: Visual internal focus of attention feedback; Participants will complete 12 sessions over a 3-week period of functional movement retraining while receiving visual feedback via laser. Participants will be instructed to perform each functional task in a manner that does causes the laser to move up and down but not side-to-side.
Experimental: Auditory external focus of attention feedback; Participants will complete 12 sessions over 3 weeks receiving auditory feedback of their movement patterns.	Other: Auditory external focus of attention feedback; Participants will complete 12 sessions over a 3-week period of functional movement retraining while receiving auditory feedback. Participants will be instructed to perform each functional task in a manner that does not cause the auditory tool to elicit a noise.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes from baseline in lower extremity biomechanics during landing.	Hip and knee angles and loads measured via 3D biomechanics	1-week post-intervention, 4-weeks post-intervention
Differences in biomechanical changes between visual and auditory external focus of attention feedback.	Hip and knee angles and loads measured via 3D biomechanics	1-week post-intervention, 4-weeks post-intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes from baseline in cortical activity during landing	Electroencephalography recording of cortical activity during landing	1-week post-intervention, 4-weeks post-intervention

Collaborators and Investigators

• Sponsor: University of North Carolina, Charlotte

Study record dates

Study Major Dates

• Study Start (Actual): August 15, 2021
• Primary Completion (Actual): February 28, 2025
• Study Completion (Actual): March 31, 2025

Study Registration Dates

• First Submitted: June 3, 2021
• First Submitted That Met QC Criteria: June 3, 2021
• First Posted (Actual): June 7, 2021

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Knee Injuries; Anterior Cruciate Ligament Injuries
• Other Study ID Numbers: 21-0283

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: No