"If you don't take care of your knees, you can develop a range of knee problems, including arthritis, tendinitis, bursitis, and cartilage damage," adds board-certified orthopedic surgeon Christopher Sforzo, MD. "These can lead to severe pain, swelling, stiffness, and even disability."

With that in mind, read on to find out what experts say your knees definitely wish you'd stop doing.

According to Kathryn Sawyer, DPT, a board-certified orthopedic clinical specialist and Director of Clinical Education at Tufts University, leading a sedentary lifestyle is one of the worst things you can do for your knees. "Your knees are designed to move, and sitting for long hours can lead to stiffness and tightness in the knee joint," says Sforzo.

Grant Radermacher, DC, owner of Ascent Chiropractic, also notes that the structures supporting the kneecap can get fatigued by a constantly flexed knee, making them more prone to injury.

For these reasons, both Sforzo and Radermacher strongly advise taking breaks to get up and move around every 30 minutes or so.

"You can also do knee-strengthening exercises, like squats or lunges, during your breaks," Sforzo adds.

Werner stresses that strength is a key component of joint health. "A lot of people think squats are bad for their knees, or they may worry that lifting weights will lead to injury or wear out their joints," Sawyer adds. "However, the opposite is true: movement, exercise, and activity are actually some of the best strategies we have for keeping our joints healthy in the long run."

If you're dealing with knee issues, Werner notes that biking, swimming, and using an elliptical machine are great options for engaging the joints without putting too much impact on them. "Pain is not a sign that you should avoid any use," he explains. "Pain is a sign that you should avoid doing whatever caused the pain."

Don't ever try to just push through or sleep off knee pain with some over-the-counter medication, says Mauricio Garcia, a board-certified orthopedic surgeon and project support coordinator for Hyper Arch Motion. Instead, he advises listening to your body, discontinuing any activities that exacerbate the pain, and seeking help from a medical professional.

For example, if your knee is buckling or otherwise unable to bear weight, or if you hear a sharp pop after changing directions quickly, Warner recommends seeing your doctor, or at the very least a physical therapist, to rule out an injury. "Injuries don't get better without rehabbing them," he tells Best Life. "They just get worse and then go on to become other problems."

This is especially true as you age, and your knees are more vulnerable. "If your pain is limiting your daily activities, your body is telling you that you need to get your knee checked out," adds Marc Matarazzo, MD, a board-certified orthopedic surgeon at The Center for Bone & Joint Surgery. "An early diagnosis can be the difference between recovery and permanent damage."

While it's fine to don a pair of sky-high stilettos once in a while, Sforzo says wearing high heels every day can cause some serious long-term issues because they put a lot of stress on your knees—especially the kneecap, or patella.

"They also alter your gait, which can lead to knee pain, inflammation, and even osteoarthritis," adds Sforzo. "If you must wear heels, try to limit the height to two inches or less, and wear them for short periods of time. Consider wearing shoes with a wider toe box and good arch support."

Running and jumping can certainly get your heart rate up and challenge your muscles, but according to Sforzo, these kinds of high-impact activities can also put a lot of stress on your knees. If you have weak quadriceps or hips, you have a higher risk of injury.

That's not to say you have to avoid high-impact exercises altogether. However, Sforzo says it's crucial to warm up properly beforehand, use proper form, and wear the right supportive shoes. It's also a good idea to alternate high-impact exercises with low-impact ones.

While we're on the subject of exercise, Micah Lissy, MD, PT, an orthopedic doctor at MSU Health Care Sports Medicine, strongly advises against doing loaded squats deeper than 90 degrees, as this can put a lot of stress on the meniscus—a pad of cartilage that acts as a shock absorber for the knee.

If you're only running, biking, and using the elliptical in a forward motion, you might want to switch things up. "Your knees are a hinge joint, meaning they can only flex and extend, much like a door hinge," explains Rebecca Pudvah, PT, a board-certified orthopedic specialist at Athletico Physical Therapy. "However, the stresses in our life come in all planes, and therefore it is important to strengthen your hips and ankles to manage lateral and rotational forces to prevent excessive load and injury to the knee."

Pudvah recommends trying side lunges and skater jumps, or cycling backward to challenge and strengthen your knees in new ways.