Of all the exercises we employ with our clients, the one exercise that is most often met with skepticism or resistance (no pun intended) is the Leg Extension. “My physical therapist (insert chiropractor, MD, or church pastor) says I can’t do Leg Extensions.” The purported detrimental effects of Leg Extensions range from causing knee injuries to being unsafe for people who have undergone knee surgeries to claims that the exercise “doesn’t transfer to real life.”
The disdain for Leg Extension is utterly surprising to me because there are very few exercises that are MORE supported by the preponderance of scientific research than Leg Extensions. In studies involving all different populations with all different outcome measurements the consistent theme is this: Leg Extensions are safe; help patients recover from invasive surgeries such as ACL reconstruction; improve long term surgical outcomes when compared to traditional “closed-chain” exercises (squats, leg presses, etc.); and significantly improve quadriceps strength relative to all other exercises. The medical, physical therapy, and exercise science research doesn’t suggest that Leg Extensions are simply safe; but that Leg Extensions are safe AND produce better results that traditional strength training exercises for a wide variety of patients with knee dysfunction.
Take Home Message: For the vast majority of trainees, if your goal is healthier knees, stronger quadriceps, and more functional strength in the lower body, Leg Extensions should be a part of your strength training script.