Females in sports that involve jumping, pivoting, and changes of direction, are 4-8 times more likely to suffer a knee injury, than males in the same sports. Most of these injuries are with females between the ages of 15-25 and are non-contact in nature. One of the root causes of the prevalence of ACL Injuries among female athletes in sports that feature jumping and cutting is found in Laura Ramus's quote, "Genetically, the typical female demonstrates less muscle mass and strength than males. Girls who are 9, 10, and 11 years old play sports in an upright position causing weak trunk, hip and leg musculature. As they continue to develop as young athletes, if this weakness and technique errors are not corrected, they will develop a muscle memory that reinforces playing in a more upright position. If this continues, they will also not develop strength to obtain good low positioning. So no matter how much the coach tells you to "get down", you will be unable to do so."
The straighter your leg is when you land, the less force it takes to tear your ACL. Dr. Edward Wojtys, head of sports medicine at the University of Michigan said, "If you can do nothing else but get women to jump and land in a more flexed knee position, that will help". In basketball alone, nearly 60% of ACL injuries to female athletes occur when landing from a jump. (source: American Academy of Orthopaedic Surgeons). Caraffa, Cerulli and Projetti report that the three main non-contact knee injury mechanisms are; planting and cutting, straight-knee stopping, and one-step landing with the knee hyper-extended. All three of these scenarios can be manifestations of playing in a more upright position. Dr. Jesse Morse states "Common mechanisms of injury include pivoting during acceleration or deceleration, and forcefully landing on the heel with a small knee flexion angle. If the ACL is torn during a contact-induced injury, it is usually due to severe valgus stress on the straightened knee." These basketball, soccer, and volleyball links point out primary mechanisms for ACL injuries in those sports.
Prevention is always better than a cure, so obviously, coaches, parents, trainers, and Physical Education Teachers need to attempt to address this for both males and females at the early stages. So first and foremost, consider exposing your female and male athletes to some, training, drills and exercises that help them develop strength and the ability to bend, cut, jump, andland properly. For the video on landing properly from the previous sentence, I don't recommend emphasizing "not letting the heels touch on the landing". This can encourage an athlete to try to stay up on the forefoot during the landing and can result in tight calves. Note how the trainer in this very imformative jumping and landing video lands on his forefoot but allows his heels to lightly touch the floor.
Learning situations for the sport which may lead to injury, as were demonstrated previously, as well as learning the risk factors such as knees buckling in as the athlete bends, jumps, lands, cuts, and/or shuffles, will allow coaches, trainers, teachers, and parents to assess their athlete's possible susceptibility to knee injury before deciding; how to proceed. Coaches having knowledge of the risk factors and an eye for detail is also very important to allow the coach to individualize the instruction. Athletes that are bending, jumping, landing, cutting, or shuffling improperly need training that emphasizes correcting those flaws, ie; training to correct knee buckling rather than a focus on more advanced training that may have the athletes doing repeated explosive movements in an unsafe manner. While assessing the athletes you also may find some that already have some good habits, in regards to knee care, that you want to preserve. Being an alarmist, and making a big deal out of the possibility of injury when speaking to and training the athletes, may disrupt what they are already doing well, and may even create fear and negatively affect play.
A portion of the basketball video in the second paragraph made some great points about the mechanics of running and how landing on the forefoot reduces injury risk. Please realize, however; that when athletes run fast (sprinting), it is natural for the athlete to land higher on the forefoot than when running slower. Watch the first minute of this video and watch the runner on the right side of the screen to note what landing on the forefoot should look like when running at a pretty slow speed. It is encouraging to see how after just two weeks of instruction that the runner improved upon the form that you saw her have on the left side of the screen. When an athlete is trying to run fast, then it is desireable to be high on the forefoot as Russell Westbrook and Lebron James were in the basketball video shown previously. An athlete inappropriately trying to land high on the forefoot, ie; when running at slower speeds, can end up with tight calves, shin splints, etc...
In addition, it is very important for the athletes to practice sound jumping and landing skills. This video demonstrates jumping from two feet and this video demonstrates jumping from one foot. Watch how the feet land in the last steps in this jumping video. Thisvideo emphasizes Lebron James' great landing technique after jumping and shows how he runs on his forefoot. Training that improves athletes ability to land appropriately on their forefoot while running is a process that should be directed by someone with sufficient knowledge.
Watch your athletes when they are doing sprints of some type from a standing start. Note how some are well bent when waiting for the "go" command, while some are pretty upright and are waiting to bend as they begin. Go to the 3 minute 15 second mark of this video and note how every athlete is bent and ready to move when in the "set" position. You want your athletes to get the connection between bending properly and moving productively, but once again, many may need the training to develop the strength to bend properly. For your more advanced athletes doing some sprints from a proper three point stance can help further strengthen the muscles needed to move well from a low position. If doing sprinting with your athletes be sure to advise them to decelerate under control to help avoid injury as is demonstrated in this video.
After giving attention to; assessing injury risk, learning to jump, land, and cut properly; learning to strengthen key areas, etc..., performing plyometrics that are appropriate to the conditioning and maturity level of the athlete is very important. Check out the many different Med Star Health Plyometric videos for starters.
It basically comes down to learning how to help the athletes develop the strength, flexibility, balance, range of motion, explosiveness, and technique needed, to be able to play and execute various skills and movements, in as safe a manner as possible, as well as be able to handle the inevitable instances where the injury risk may be higher, ie; awkward landings.
Cincinnati Sports Medicine reminds women to jump "straight as an arrow" and land "light as a feather", landing toes to heels and keeping ankles bent. It achieved a 22 percent reduction in landing force with its 6- week Sportmetrics Program. Learning how to strengthen the core is also important, as Laura Ramus noted, "Strengthen your core muscles-back, abdominals, hips - not just your legs. That's where your strength comes from to play in a more crouched and knee-protecting position."
Ideally, knee care training should begin in the off-season. For starters, parents and coaches can assess their athletes for susceptibility to knee injury with the simple tests shown in this video, and then have a plan of action should the assessment reveal some concerns. There also should be some type of effort to assess the athletes to see whose; bending, running, jumping, landing, cutting, and stopping movements seem to predispose them to the injuries as was demonstrated in this blog, and have a plan that hopefully includes improving the incorrect movement patterns before exposing the athletes to repetitive and intense movements that could prove troublesome.
One strategy for off-season, pre-season, and during the season, is to include exercises, drills, and activities during warm ups that can promote good knee care. First of all it is critical to have a warm up that sufficiently loosens the joints, and body in general, and eases the athletes into being able to safely compete in an explosive manner. Laura Ramus demonstrated three different types of activities that could be alternately woven into a team's warm up. For one practice exercises like squats, and a few types of single leg squats could be blended in to work on strength and proper bending. For another practice balance activities could be blended in having the athletes stand on one leg that is bent some, and have them do ballhandling drills, passes, and reaching up and back with the ball, and for another practice mix in various jumping from both legs and hopping from one leg activities to practice good jumping and landing skills.
At the end of the day, especially when dealing with females, if you don't make a conscious effort to work on it, many will settle into bad habits when it comes to bending, jumping, landing, pivoting, and cutting.