Any athlete’s worst fear—professional or amateur—is injuring themselves to a point that prevents them from continuing to work out. But, the reality is, exercise injuries are far more common than we think. According to the Centers for Disease Control and Prevention (CDC), hundreds of thousands of exercise injuries occur each year. Among these, knee injuries are the most common. Experts agree that the best thing to do if you fall victim to a knee injury is to seek help—and to know the signs that signal something serious. Here are seven that should prompt an immediate visit to your doctor’s office.
You’re experiencing swelling.
One of the most obvious signs that a knee injury has occurred is excessive swelling that you can see or feel. In fact, this symptom is most indicative of a serious cartilage or ligament injury to the knee, according to Taylor Brown, M.D., an orthopedic surgeon at Houston Methodist in Texas. If your knee doesn’t immediately appear swollen and you’re unsure, “feel the injured and normal knee at the same time, with a hand on each knee to compare the two,” he says. “A swollen knee will feel like a large, warm, fluid-filled balloon.”
If you experience any of the above, he recommends the RICE principle. Rest with crutches and activity reduction, ice for 20 to 30 minutes several times a day, compression with a soft knee sleeve brace, and elevate your knee above the level of the heart. Over-the-counter pain medication can also provide relief until the swelling goes down.
You notice an obvious deformity.
If you notice your knee jutting outward in a way it never has before, take note. A dislocated or fractured patella (kneecap) can cause injuries like this, explains Brian Schwabe, C.S.C.S., board-certified sports physical therapist based in Los Angeles. If you notice a bone deformity after an injury, he recommends seeking the assistance of an orthopedic doctor immediately.
You felt or heard a “pop”.
Sometimes, a “popping” sound after a movement can indicate something is out of place. “Oftentimes this type of sound upon injury is indicative of a ligamentous injury,” says Schwabe. Not all ligamentous injuries are full tears, though, and not all require surgery. However, if you also experience excessive swelling and instability, get it checked out by an M.D. “If you only have a mild sprain then you will be able to rehab it with physical therapy,” he says.
You experience greater than normal movement.
If you feel like your range of motion in the knee is higher than usual, something might be out of place or injured. This is known as joint instability. You may feel like your knee will buckle or fold with walking, twisting, or weight-bearing. “The sensation of the knee giving away may occur with simple daily activities or upon return to sport following what was thought to be a minor injury,” explains Dr. Brown. “Additional episodes of joint instability may worsen the condition of a knee after an injury.” Tears of the ACL or MCL and patellar (kneecap) dislocations could also create joint instability, he says.
The best plan of action is to make an appointment with an orthopedic surgeon. Wear a compression-sleeve-type brace or a knee brace with hinges in the interim, says Dr. Brown. This may provide some comfort or level of support. Use crutches if you feel like you could fall and suffer additional injury because of knee joint instabilty.
You can’t put weight on it.
If it’s immensely painful to stand or put any weight on your injured knee, there’s definitely something serious going on. “Inability to bear weight after a knee injury could be caused by a fracture, bone contusion, cartilage injury or ligament tear,” explains Dr. Brown. “Initial treatment includes using crutches to take pressure off the injured limb and minimize additional damage to the knee.”
If this sounds like you, listen to what your body is trying to tell you. Dr. Brown warns that the old adage of “no pain, no gain” doesn’t apply in this situation. He advises seeking orthopedic evaluation as soon as possible—even that same day if you can.
You can’t straighten your leg.
If you have trouble straightening your leg or it hurts to do so, you probably have a serious knee injury. To test this, start in a seated position and try to lift your lower leg using your own leg muscles. “You may still be able to bear weight and walk slowly and carefully without assistance, but will probably require assistance to lift your lower leg and fully extend your injured knee,” says Dr. Brown. “Patella fractures, quadriceps tendon tears, and patellar tendon tears all tend to be associated with an inability to straighten the leg.”
Use a knee immobilizer to hold the knee in a straight position and help with pain relief. This also makes it easier to move about until your appointment with an orthopedic surgeon, he adds.
Your knee keeps buckling.
A torn ACL or a large meniscus tear are two common injuries—both serious—that may cause this symptom to occur, says Aideen Turner, physical therapist and CEO of Virtual Physical Therapists. “If your knee buckles under you when you are walking, then it usually indicates instability,” she says. “A lot of people have ACL tears, but if the knee still has functional stability, then surgery is not necessarily needed. But the buckling indicates damage to the cartilage, which means surgery should be performed.”