"Contrary to popular belief, evidence only exists showing that the more ability you have with your knees over your toes, the less chance you have of knee pain and surgery," writes Ben Patrick on his Medium page. Patrick is a knee-strength coach who's extensively researched knee injuries, having had three surgeries by age 18 and suffered multiple torn ligaments. He points to a 2016 study published in Medicine & Science in Sports & Exercise that followed people after anterior cruciate ligament (ACL) reconstruction and found that step-down and quadricep training improved performance six months after surgery.