ACL: Anterior cruciate ligament. SLIDESHOW Pictures of the 7 Most Effective Exercises to Do at the Gym or Home (and Tips to Improve Form) See Slideshow From Fitness Resources Healthy Food Choices While Eating OutTips for Weight Loss and MaintenanceBringing Up Weight Loss With Your Doctor Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19