Related Experiment Video
Updated: May 23, 2026
Early Weight-Bearing Rehabilitation Protocol After Anterior Cruciate Ligament Reconstruction
Published on: March 1, 2024
Neuromuscular changes after aerobic exercise in people with anterior cruciate ligament-reconstructed knees
Elizabeth C Dalton1, Kate R Pfile, Gerald R Weniger
1Atlantic Physical Therapy, Norfolk, VA, USA.
Context:
Anterior cruciate ligament (ACL) reconstructions are common, especially in young, active people. The lower extremity neuromuscular adaptations seen after aerobic exercise provide information about how previously injured patients perform and highlight deficits and, hence, areas for focused treatment. Little information is available about neuromuscular performance after aerobic exercise in people with ACL reconstructions.
Objective:
To compare dynamic balance, gluteus medius muscle activation, vertical jump height, and hip muscle strength after aerobic exercise in people with ACL-reconstructed knees.
Design:
Case-control study.
Setting:
Research laboratory.
Patients Or Other Participants:
Of 34 recreationally active volunteers, 17 had a unilateral primary ACL reconstruction at least 2 years earlier and 17 were matched controls.
Intervention(S):
All participants performed 20 minutes of aerobic exercise on a treadmill.
Main Outcome Measure(S):
We recorded dynamic, single-legged balance electromyographic gluteus medius muscle activation, single-legged vertical jump height, and maximum isometric strength for hip abduction, extension, and external rotation preexercise and postexercise.
Results:
Participants with ACL reconstructions exhibited shorter reach distances during dynamic balance tasks, indicating poorer dynamic balance, and less gluteus medius muscle electromyographic activation. Reductions in hip abduction and extension strength after exercise were noted in all participants; however, those with ACL reconstructions displayed greater hip extensor strength loss after aerobic exercise than did the control group.
Conclusions:
Neuromuscular changes after aerobic exercise exist in both patients with ACL reconstructions and controls. The former group may experience greater deficits in hip extensor strength after aerobic exercise. Reduced reach distances in people with ACL reconstructions may represent a protective mechanism against excessive tibiofemoral rotation during dynamic balance. Clinicians should identify weaknesses in the resting state and after aerobic exercise in recreationally active patients and those with ACL reconstructions.
