As the largest joint in the body, the knee does some heavy lifting … and is prone to injury.

“The knee relies heavily on ligaments to support it,” said Dr. Alex Meininger, an orthopedic surgeon in Steamboat Springs and a member of the medical staff at UCHealth Yampa Valley Medical Center. “It undergoes a lot of strain to fulfill its range of motion through the course of normal activities, so it’s prone to injuries.”

Below, Meininger outlines the most common knee injuries and how a regimen of stretching and strengthening can help with prevention.

ACL tear

The most common and dramatic knee injury is a tear to the anterior cruciate ligament or ACL.

“The knee is a hinge, and relies on the ACL for central stability,” Meininger said. “An inadvertent twist or fall can predispose that ligament to tearing.”

ACL tears are most common among downhill skiers and football players but can result from various other activities, including cycling, snowmobiling and dirt biking.

Muscle imbalances, such as when the quads are stronger than the hamstrings, can also predispose you to injury. “Think of a teeter-totter,” Meininger said. “If one muscle pulls too hard, that central ligament can be strained.”

When a tear does happen, people usually know.

“You may have difficulty bearing weight or swelling in the joint,” Meininger said. “Anytime the knee is swollen, that’s a sign there’s something wrong with the knee that needs to be evaluated.”

Surgery will most likely be necessary: the ACL is bathed in joint fluid, so it does not easily heal on its own.

Meniscus tear

The second most common knee injury is a tear to the meniscus, which is a pair of cartilage pads between the femur and tibia bones that helps cushion and stabilize the knee joint.

“These tears can happen during a deep-knee bend, a twist on the ice, a slip and fall,” Meininger said.

Since the meniscus receives limited blood flow, it also does not heal easily, so it may need to be surgically trimmed or repaired.

“The goal is to save that cushion and supporting structure so the rest of the knee is not under undue stress and pressure,” Meininger said.

Difficulty bearing weight and swelling in the knee are also signs of a meniscus tear, as is limited motion – with a torn meniscus, you may not be able to fully bend or straighten your knee.

Preventing common knee injuries

Regular stretching and strengthening are key to healing from an injury. “Even a simple meniscus tear benefits from a core strengthening program,” Meininger said.

And, it can help with prevention, especially when it comes to overuse issues.

“You should stretch within your normal range of motion, and work on strength to gain core stability to help react in time before an injury occurs,” Meininger said.

Loose, limber muscles are better able to respond to quick movements and allow the knee to maintain normal motion.

And strength should be built across the body, from the ankles through the hips and core. Hip strength is especially important to knee stability, as weak or rotated hips can stress the knees.

“All the elements are linked together,” Meininger said. “Injury or overuse in one area can predispose you to injury in another area.”

Meininger recommends developing a strengthening program with the help of a physical therapist, athletic trainer or other professional, who can help diagnose weaknesses and instabilities. Then, do the program regularly.

“If you’re able to keep it up two to three times a week, you’ll keep those neuromuscular feedback loops active so your muscles stay responsive,” Meininger said.

This article first appeared in the Steamboat Pilot & Today on Feb. 11, 2019.