Why Does the Leg Press Exercise Hurt My Knees?

When it comes to the best exercise for building strong quads and glutes, many people opt for the leg press machine. While this machine is a top pick for many gym-goers, it's not uncommon to experience leg press knee pain, especially if you have an injury, use too much weight or have improper form.

Pain, while exercising or immediately following physical activity, is cause for concern. That's why finding out why you have leg press knee pain is so important in preventing and treating any potential injuries.

"During the phase of the leg press that involves deep knee flexion, the stress goes to the posterior aspect of the knee, or back of the knee, and the bones and cartilage in the back of the knee," Dr. David Geier, MD, orthopedic surgeon and sports medicine specialist, tells LIVESTRONG.com. Often, Geier says that area is where cartilage damage and other structural damage like meniscus tears are found. "Applying a large amount of stress to that part of the knee can cause pain in someone with early arthritis or other injuries," he adds.

According to the Mayo Clinic, a knee injury can affect any tendons, ligaments or bursae that surround your knee joint. Additionally, it can also harm the bones, cartilage and ligaments that form the joint. If you're ‌experiencing nagging knee pain‌ that won't go away, consider calling your doctor if you can't bear weight on your knee, you're experiencing swelling in and around the knee, are unable to fully extend or flex your knee, or you see a deformity.

‌Read more:‌ 5 Common Workout Injuries and How to Avoid Them

Whether you're a seasoned athlete dealing with leg press knee pain or you're new to working out, you might be wondering if including this exercise in your lineup is a good idea. "Generally speaking, the leg press is safer than many other knee exercises, especially leg extensions," explains Geier. This is because the leg press is a closed chain exercise, which means the feet are planted on the plate of the machine.

That said, when ‌done improperly or with too much weight‌, you can put unnecessary strain on your knees, which may cause pain or injury. Since improper technique can lead to injury, the American Council on Exercise stresses the importance of controlling the extension phase by keeping your heels in contact with the platform, while also avoiding the urge to lock out your knees.

And when it comes to the load you're pressing, Geier says to ‌start with lighter leg press weights‌ and perform more reps until you see how this exercise feels for you and your knee. "If you do have knee pain from a prior injury or just wear and tear from years of being active, consider not going as deep with the exercise," he explains. And limit the knee flexion to 90 degrees, when your knees are bent at a right angle.

‌Read more:‌ Seated Leg Press vs. Squats

If you've figured out the glitches or issues that are causing your knee pain, and you're able to resolve them, there are a few things you can do to make the leg press more effective.

Since most platforms on leg press machines are large enough to change your foot position, use this to your advantage to target different areas of your lower body. For example, to put more emphasis on the gluteus maximus, ExRx.net recommends placing your feet slightly higher on the platform than the original position, and if you want to target the quadriceps, shift your feet slightly lower on the platform.

A solid training plan requires the use of ‌different exercises to target your lower body‌. The leg press should serve as one possible exercise you can do when it's leg day. Another exercise similar to the leg press you can try is the squat.

Geier says the squat is like the leg press because it also requires you to keep your feet planted on a fixed surface (the floor). "This allows for both your quads and hamstrings to contract, protecting the knee during the motion," explains Geier. In addition to the squat, you can also incorporate various lunges, deadlifts, rear-foot elevated split squat and box step-ups.