There are many physiological and anatomical differences between men and women beyond the obvious ones -- including, as it turns out, vulnerability to orthopedic injuries. It appears that how women are built leaves us -- and our daughters, like my two soccer players -- four times more likely to suffer knee injuries, especially to the anterior cruciate ligament (ACL) in the knee joint. Although the ACL is the smallest ligament in the knee, the fact that it is part of the connective structure between the femur (thigh bone) and tibia (shin bone) makes it critical to stability. A torn ACL can be painful and often requires surgery, followed by four to six months of physical therapy to regain proper functioning and return to sports. New research provides an improved understanding of how to protect yourself from the risk of injury -- not to mention the resulting pain and cost for treatment.
RESEARCH TO DATE
Research a few years ago revealed one major cause of ACL injury in women -- after a jump, as in basketball or volleyball, females tend to land with straighter legs than males do, which puts more pressure on the ACL. Research also has shown that females often have an imbalance between the strength in their quadriceps muscles in the front of the thighs and the hamstring muscles in the back of the thighs. This alters knee functioning and may affect stability.
The newest study on female knees comes from the University of Michigan, Division of Kinesiology, adding a subtle but important additional clue to the ACL/female injury issue. Researchers found that many women athletes maintain a knock-kneed position when landing after a jump. When I called orthopedic surgeon Jo A. Hannafin, MD, PhD, at the Hospital for Special Surgery in New York City to learn more, she told me that knock-knees come about for several reasons. Some people (both male and female) are simply born this way -- it is the anatomic alignment they were given. But often it is due to yet another muscle imbalance, this one between the inner (medial) and outer (lateral) thigh muscles. In this study, researchers determined that females -- even those who are not knock-kneed -- tend to activate the stronger outer thigh muscles in preparation for a landing. Without equally strong inner thigh muscles to provide balance, the knees rotate even further inward, increasing the risk to the ACL. Playing primarily one sport year-round or repeating the same exercise routines makes injury even more likely -- repetition of one activity builds only the muscles the particular sport requires, and may create a strength imbalance, says Dr. Hannafin. Cross training helps avoid this problem.
Not only jumping sports but any that involve torquing the knees -- the twisting that is inherent in skiing, tennis or even ballroom dancing -- puts pressure on the knee and increases risk of injury, says Dr. Hannafin. This makes it important for all active women to pay special attention to their knee positioning and muscle strength balance.
To find out if your inner and outer thigh muscles are balanced, Dr. Hannafin suggests doing a mini-squat on one leg (described below) -- if the bent knee goes toward the other knee rather than remaining pointed out straight, it shows weakness of the inner thigh muscles and the muscles of the hip and buttock that rotate the knee outward.
PROTECT YOURSELF
Strengthening and balance training exercises to build up the muscles and paying close attention to how you jump, land and pivot can help you avoid such injury. For example, focusing on trying to land with knees that are slightly bent, or decelerating before switching directions when you're moving quickly (as in tennis) may help, according to a report by the Journal of Athletic Training. Here are some suggestions from Dr. Hannafin:
Wear the right shoes. Key: Supportive shoes with a good, strong sole. Avoid flip-flops, sandals and fashion flats as these can aggravate problems in people who are flat-footed or who pronate excessively. Look for sandals with a built-in arch or use an arch support in your shoes.
Stand straight. Pay attention to how you position your hips during all activities, including standing. You can get some sense of this by doing your exercises in front of a mirror, but if you are serious about sports, consider an assessment by a sports physical therapist.
Strengthen hips. Strengthening hips also helps prevent injury. One way to do this is with hip abductions, says Francesco Gallaro, MSPT, CSCS, a certified strength and conditioning coach and physical therapist in Norwalk, Connecticut. These also serve to strengthen gluteus muscles. Do two or three sets of eight to 12 reps of standing resisted hip abductions, using a rubber band. Kick one leg from the midline of your body to the side in a backward diagonal direction. Note: Kick should be a smooth continuous motion. Try to complete the entire set without the foot touching the ground. Good hip strength prevents the knee from rolling inward into a knock-kneed position.
Balance thigh muscles. To strengthen and balance the thigh muscles, Dr. Hannafin advises making a routine of the one-sided mini-squat mentioned earlier. Keep the gluteus (the muscles of your buttocks) tight and pay close attention to activating muscles on both sides of the leg. To perform this exercise correctly, stand on one leg. Bending from the knee, lower your body down until your knee is bent to 45 degrees (you don't have to go all the way to a sitting position for it to be effective). Raise yourself back up. Do two or three sets of 10 repetitions, each leg.
Strengthen the hamstring (for the quad-hamstring imbalances mentioned earlier). Gallaro suggests the deadlift. Stand on one leg, bend your body forward at the waist so you are at a 90-degree angle. Raise yourself back up -- do three sets of eight to 12 reps. The leg not in contact with the floor should be straight and in proper alignment with your trunk. Try performing a set without letting your foot make contact with the ground. As you get stronger, you can do this exercise while holding weights.
Perform leg strengtheners. Leg presses at the gym are also helpful -- but with a strong caveat, says Dr. Hannafin. It's important to maintain proper form, keeping your knees over your feet. Women tend to squeeze their knees together as they push against the platform -- this further strengthens and trains the outside of the quad to do the work, leaving the inner thigh muscles getting weaker. Try placing a small ball between your knees when you are on the leg press.
Don't ignore your core. Finally, Dr. Hannafin recommends core strengthening exercises. Having strong pelvic and lower abdominal muscles, interestingly, helps to protect your knees. Pilates is good for this, of course, as are assorted core-exercise programs that employ large exercise balls.
Source(s):
Jo A. Hannafin, MD, PhD, orthopaedic director, Women's Sports Medicine Center, Hospital for Special Surgery, New York City.
Francesco Gallaro, MSPT, CSCS, a certified strength and conditioning coach and physical therapist in Norwalk, Connecticut.
1 comment:
Try performing a set without letting your foot make contact with the ground. As you get stronger, you can do this exercise while holding weights.
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