How to Keep Your Knees Healthy
By Linda Melone, CSCS, Special to Lifescript
Published April 23, 2011
Healthy knees are important to your well-being, but painful injuries like “runner’s knee,” ACL tears and tendonitis are all too common. In fact, women are more likely than men to suffer serious knee trouble. Read how the knee works, what can go wrong and how to prevent getting hurt. Plus, learn how to strengthen leg muscles and reduce pain with a knee workout…
Although they’re the largest joints in the body, your knees are also among the most vulnerable to injury. And women face a higher risk, especially if they’re active.
But if you take precautions, you can reduce the likelihood of painful or even debilitating damage.
“Knee injuries generally fall into two categories: macro traumas and overuse injuries,” says John Hurley, M.D., an orthopedic surgeon at Summit Medical Group in Morristown, N.J.
Macro trauma includes tearing of a tendon or cartilage, usually the result of turning and twisting during running or sports. A tear can also occur when you stop short with feet planted in one direction and the knee forced into a different direction.
An overuse injury, on the other hand, often occurs from asking too much of your knees without enough rest.
And while they’re not completely preventable, both kinds of injury can usually be avoided with proper care.
Anatomy of a Knee
To understand how these problems happen, it’s helpful to know what makes your knees work.
Ligaments are stabilizers that hold your knee together. Two on each side prevent it from moving side to side. One on the inside and outside prevent it from collapsing in either direction.
A wrong step or sideways collision can easily result in a strain or tear. Women are two to eight times more likely to experience a tear of the ACL (anterior cruciate ligament – one of the knee’s stabilizing ligaments) than men.Knees also contain two types of cartilage – one of which coats the surfaces of bones, enabling them to glide past one another. When this cartilage wears away through stress or misalignment, the bone-on-bone rubbing creates pain and ultimately can lead to arthritis.
Another type of cartilage, the meniscus, acts as a shock absorber.
Then there are the muscles that control the knee – in front of your thigh (quadriceps) and behind your it (hamstrings).
Why Women Are at Greater Risk for Injury
Due to both anatomical differences and monthly hormonal fluctuations, women are more likely than men to suffer knee injuries during sports and exercise.
Wider hips create more of a lateral pull on the knee (think “knock-kneed”), which stresses the ligaments.
Also, in activities such as jumping, men absorb a landing better, says Peter J. Millett, M.D., a sports-injury specialist with Steadman Clinic in Vail, Colo. Women tend to rely more on their quadricep muscles and land with their knees locked out, which requires the knee to absorb all of the force.
Muscular imbalances may be to blame.
“Women tend to be ‘quad dominant,’ while men have more equal strength in both quadriceps and hamstrings,” says orthopedic surgeon C. David Geier, Jr., M.D., director of sports medicine at Medical University of South Carolina.
Weaker core strength in women can be a factor as well: “Less muscle mass makes you fatigue more quickly, making injuries more likely,” Hurley says.
That’s especially true if you decide to get active after 40. Sometimes women will jump right into a program of running, tennis or other sports without considering the loss of muscle that occurs with aging.
And then there are hormones. “Estrogen ebbs and flows have a subtle effect on ligaments,” Millett says. “At certain times of their cycle, women may have looser ligaments, putting them at higher risk of injury.” Avoid That Ache
By taking protective measures, you can reduce your chances of getting hurt. Here are the most common causes of knee pain and injuries, along with ways to prevent them.
Patellofemoral Syndrome (“runner’s knee,” or chondromalacia)
What it is: Pain under the patella (kneecap) in the front of the knee that typically worsens when squatting or walking downstairs. You may hear grinding or clicking noises.
What causes it: Abnormal softening and/or breakdown of the cartilage under the kneecap due to poor kneecap alignment. Muscle tightness, overpronation (when the foot rolls out to the side while you’re walking) or weak thigh and glute muscles contribute to the problem.
Symptoms can be brought on by a change in a workout or activity level, Hurley says. For example, a sudden increase in running mileage may trigger the pain.
Women often start to complain of knee pain when their children are 12 to 16 months old. “Imagine carrying a 20-pound weight up and down stairs,” Hurley says.
Expert advice: Identify the trigger and look for ways to modify your activities. Also, work on strengthening quadriceps and core muscles.
ACL (anterior cruciate ligament) tear
What it is: The knee “gives out” – most often during a sport – and you may hear a loud pop as the ligament tears. Pain and swelling quickly follow.
What causes it: A sudden change in direction while running, pivoting or getting hit from the side of the knee can strain or tear the ligament.
Expert advice: Rehabilitative strengthening can help, and in some cases you may benefit from surgery. See your doctor to determine the best approach for your situation and identify exercises to restore strength and motion. IT (iliotibial) band syndrome
What it is: Common in runners as well as some tennis players and cyclists, this injury occurs when the IT band – fibrous tissue that runs from the top of the hip to the outside of the knee – tightens or becomes inflamed. This causes pain on the outside of the knee, typically after a mile or two into a run.
What causes it: Overuse, often from running for several days in a row without enough rest or cross-training. Differences in leg length or an abnormal pelvic tilt may also cause IT band syndrome. So can training errors by long-distance runners, such as running on the side of a sloping road so one leg is lower than the other.
Expert advice: Rest, ice and anti-inflammatory medications usually help. “Avoid the aggravating activity and stretch the IT band,” recommends Millett. Incorporating cross-training into your workouts is also a good idea.
What it is: Swelling, irritation and inflammation of the tendons – fibrous tissue that connects muscles to bones – around the knee.
What causes it: Tendonitis usually results from overexertion. For example, “Too many squats and lunges done too fast … or training for a marathon by performing long runs on weekends, which doesn’t allow the body time to restore energy back into the muscles,” Hurley says.
Expert advice: Cross-train to use different muscle groups. “You don’t see as many overuse injuries in triathletes, who perform a variety of sports,” Hurley says.
Don’t ramp up the intensity of your workouts more than 15% at a time, and don’t change more than a single variable at once. (In other words, if you boost your running mileage one week, don’t also increase your speed.)
Osteoarthritis of the Knee
What it is: Breakdown of cartilage that leads to pain, stiffness, limited range of motion and localized swelling.
What causes it: Arthritis can result from a previous injury, carrying too much weight, genetic predisposition, fractures and tears affecting knee alignment, or repetitive strains. Expert advice: Treatment may include anti-inflammatory medications and injections of hyaluronic acid, a naturally occurring component of connective tissue that cushions and lubricates joints.
“If the pain persists or affects sleep, see a doctor,” Millett says.
“Obesity contributes to knee pain, so if you’re overweight, losing a few pounds may help,” he adds.
When to See a Doctor
Seek treatment immediately if your knee is significantly swollen or feels “stuck,” or if it buckles and gives out.
For minor knee pain, first modify your workout and activities:
- Try half-squats instead of full squats.
- Avoid knee-extension exercises (such as the gym machine where you sit with your knee bent and lift a weight with your shin).
- Give up activities such as downhill hiking, and use walking poles to take the pressure off knees.
- Instead of running, go biking or swimming. Replace the treadmill with an elliptical trainer or stationary bike.
If knee pain persists despite taking these steps, “it’s time to get it checked,” Geier says.
Try This Protective Knee Workout
If one knee is sore, Geier recommends these exercises to strengthen leg muscles and reduce pain.
Perform two sets of 25 repetitions, 7 times per week for 1 month, then 3 times per week.
Starting position: Sit on the floor, with or without a yoga mat, back against a firm surface and legs straight in front of you.
1. With foot pointed up, press the knee into the floor to tighten the muscle. Hold for 5 seconds.2. Tighten the muscles behind the knee by bending knee slightly and pressing the heel down into the floor and toward knee. Hold for 5 seconds.
3. On the leg with knee trouble, place a tennis ball can covered by a towel under the thigh, just above the knee. Raise the foot so knee is straight. Don’t raise the thigh. Hold for 5 seconds.
4. Bend the “good” knee, keeping foot on surface. Press the troubled knee down so leg is straight, and hold leg in this position as you raise it into the air. Hold for 5 seconds.
5. Keep the “good” knee bent. Turn foot of troubled leg out so toes point to the side, tighten knee, lift leg in the air, and hold for 5 seconds. Slowly return to starting position.
Are You Bad to the Bone?
For years, you’ve been the first one on the tennis courts, the weekend hiker, the intrepid gardener on your knees for hours. While all those activities are great for you, they can also be hard on your joints. Find out how much you know about protecting your joints with this osteoarthritis quiz.