Optimizing Plyometric Training for Functional Recovery Post-ACL Reconstruction

While surgical anterior cruciate ligament reconstruction (ACLR) of the knee restores passive stability, studies are showing consistently poor long-term outcomes. Unusually high risks of early-onset osteoarthritis and re-injury, and low rate of return to sport following ACLR all seem to be related to a chronic tendency to land stiff-legged from a jump or hop, which itself may be due to fear of re-injury. Decreased knee bending for force absorption simultaneously decreases performance level and increases risk for injury and arthritic changes.

The purpose of the proposed study is to compare a current best-practice plyometric training program to one utilizing body weight support to increase repetition and improve performance in the initial phases. The investigators hypothesize that we will see larger improvements in absorptive capacity of the knee and better confidence in activity immediately following body weight support training, as well as improved retention of training effects after a two-month period.

Study Overview

• Status: Completed
• Conditions: Anterior Cruciate Ligament Injury; Knee Injury
• Intervention / Treatment: Procedure: Standard Plyometric Training; Procedure: Plyometric Training with BWS

• Study Type: Interventional
• Enrollment (Actual): 47
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Montana
    • Missoula, Montana, United States, 59812
      • University of Montana, Movement Science Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years to 35 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• speak and understand English
• age between 12-35 years
• unilateral anterior cruciate ligament reconstruction between 6-48 months prior
• activity level greater than or equal to level 5 on the Tegner Activity Scale

Exclusion Criteria:

• Weight in excess of 300 pounds (136 kg)
• contralateral/bilateral ACL reconstruction or an unreconstructed ACL injury
• history of a posterior cruciate ligament injury
• lower extremity of back injury or other condition (e.g. cerebral palsy) that has limited their normal activities of daily living within the last 6 months

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Standard Plyometric Training; Participants will undergo treatment 2 times a week for 8 weeks with plyometric exercises deemed to be consistent with best practice delivered at a standard dosage of sets and repetitions.	Procedure: Standard Plyometric Training; Participants will undergo individualized practice exercises of jumping, hopping, and cutting tasks consistent with standard published exercises.
Experimental: Plyometric Training with BWS; Participants will undergo treatment 2 times a week for 8 weeks with plyometric exercises deemed to be consistent with best practice with a treatment volume of sets and repetitions that exceeds standard practice. Higher number of practice trials will be completed with body weight support (BWS) to reduce load. Participants will start at 30 percent of body weight and will be slowly weaned away over time.	Procedure: Plyometric Training with BWS; Participants will undergo individualized practice exercises of jumping, hopping, and cutting tasks consistent with standard published exercises while their body weight is supported via adjustable harness.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in sagittal plane knee kinetics and kinematics	Baseline and after 8 weeks of training
Change in psychological readiness for sports activities via survey scores	baseline and after 8 weeks of training
Change in motor patterning via electromyography of quadriceps and hamstring muscles	Baseline and after 8 weeks of training

Secondary Outcome Measures

Outcome Measure	Time Frame
Retention of Biomechanical Adaptions in Knee kinetics and kinematics	Change from end of 8 weeks of training to 2 month follow-up
Retention of adaptations in Psychological Readiness for Sport via survey	Change from end of 8 weeks of training to 2 month follow-up
Retention of adaptations in motor patterning via electromyography	Change from end of 8 weeks of training to 2 month follow-up

Collaborators and Investigators

• Sponsor: University of Montana
• Collaborators: American Physical Therapy Association; Foundation for Physical Therapy, Inc.
• Investigators: Principal Investigator: Ryan L Mizner, PT, PhD, University of Montana

Publications and helpful links

General Publications

• Elias ARC, Harris KJ, LaStayo PC, Mizner RL. Clinical Efficacy of Jump Training Augmented With Body Weight Support After ACL Reconstruction: A Randomized Controlled Trial. Am J Sports Med. 2018 Jun;46(7):1650-1660. doi: 10.1177/0363546518759052. Epub 2018 Mar 20.

Study record dates

Study Major Dates

• Study Start: January 1, 2014
• Primary Completion (Actual): December 1, 2018
• Study Completion (Actual): December 1, 2018

Study Registration Dates

• First Submitted: May 22, 2014
• First Submitted That Met QC Criteria: May 27, 2014
• First Posted (Estimate): May 28, 2014

Study Record Updates

• Last Update Posted (Actual): April 25, 2019
• Last Update Submitted That Met QC Criteria: April 24, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Keywords: Knee; motor learning; psychological factors; plyometrics
• Additional Relevant MeSH Terms: Leg Injuries; Wounds and Injuries; Anterior Cruciate Ligament Injuries; Knee Injuries
• Other Study ID Numbers: UM IRB 282-13