The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) supports a range of clinical trials studying new and existing interventions for prevention and treatment of arthritis, musculoskeletal, and skin diseases.  This trial is complete, and results are now available.

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Ongoing studies that have completed recruitment are found here.


Study Description

Nearly 1 in 60 adolescent athletes will suffer ACL injuries. Approximately 90% of these injured athletes will undergo an ACL reconstruction at an estimated annual cost of $3 billion. While reconstruction and subsequent rehabilitation allow these athletes to return to sports, they have a 15 fold increased risk of secondary ACL injuries, a tear of the ACL graft or the contralateral ACL. As a result, development of an intervention to reduce the incidence of secondary ACL tears would meet a critical need.

The long-term objective of this study is to decrease the number of secondary ACL tears by decreasing side-to-side movement and loading asymmetry. Specifically, this study proposes to evaluate a novel biofeedback training program that focuses on altering loading and movement patterns to improve symmetry and overall lower extremity mechanics in a group of 40 (20 control, 20 intervention) adolescent ACL reconstructed patients.

The core hypotheses of this study include 1) biofeedback training will decrease known risk factors for secondary ACL injuries immediately following the biofeedback program and these changes will be retained 6 week after the completion of the biofeedback program; and 2) we will be able to recruit and enroll 40 patients and retain 80% of the patients through the end of the follow-up assessment demonstrating the feasibility of the biofeedback intervention. Implementation of a biofeedback program prior to returning to dynamic athletic activities could improve physical performance outcomes, decrease secondary injury risk factors and ultimately decrease the long-term joint degeneration and development of osteoarthritis that has been associated with ACL reconstruction.


Ages Eligible for Study: 14 Years to 21 Years (Child, Adult)

Sexes Eligible for Study: All

Accepts Healthy Volunteers: No

Inclusion Criteria:

  • Provision of signed and dated informed consent form
  • ACL Reconstruction: primary, unilateral ACL reconstruction with no pain in the contralateral leg
  • Rehabilitation: need to have completed at least 4.5 months of post-operative physical therapy and be within approximately 6 weeks of being ready to be released by his/her treating orthopaedic surgeon to return to full sport participation
  • Stated willingness to comply with all study procedures and availability for the duration of the study
  • Male or female, aged 14-21
  • Willing to adhere to the ACL Biofeedback intervention regimen

Exclusion Criteria:

  • For females: currently pregnant or planning to become pregnant
  • History of more than one ACL reconstruction
  • Post-operative complications that required additional surgical intervention
  • Hospitalization for any reason other than the ACL reconstruction in the last 3 months
  • Plans for additional surgical procedures in the next 12 months
  • Live greater than 60 miles from the research lab
  • Have limitations that would prevent them from attending the biofeedback training sessions
  • Motor neuron diseases, Parkinson's disease, multiple sclerosis
  • Severely impaired hearing or speech (patients must be able to respond to phone calls)
  • No access to a telephone
  • Participating in another ACL intervention
  • Inability to understand or speak English (since this will be required for the patient-based intervention)
  • Other self-reported medical problem that would prohibit participation in the study
  • Other health condition or personal issue judged by a study team member or primary care physician to make the patient inappropriate for study participation
  • Knee extension moment limb symmetry index (LSI) greater than or equal to 90% at the time of the initial study assessment

Study Design:

Allocation: Randomized

Intervention Model: Parallel Assignment

Masking: Double (Care Provider, Outcomes Assessor)

Primary Purpose: Treatment

Study Location(s):

Virginia Tech, Blacksburg, Virginia, United States, 24060

Study Website:

Last Updated: August 2022