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, when an athlete is jumping from a running start, the take off is typically done after the rear foot contacts the ground. Once again, watch how the feet land in the last steps in this jumping video, and in thisvideo which emphasizes Lebron James' great landing technique after jumping, also shows how he runs on his forefoot, but transitions to his rear foot when jumping, so once again, coaches don't encourage your kids to make an inordinate effort to stay up on the balls of their feet. Many athletes can benefit from good sprint coaching to help in this area, and of course, a trainer that has expertise in Knee Care training can be very valuable.
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.
It is always best to consider the advice of experts, and fortunately, great resources are only a mouse click away. It basically comes down to learning how to help the athletes develop the strength, flexibility, balance, range of motion, 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."
In conclusion, note that this blog has been written to coaches, parents, teachers, and trainers. The objective of this writing is to shine a light on an area that I believe should be considered as part of the basics, and can easily be included into practices during conditioning, skills practice, and other training methods. I whole heartedy invite coaches, trainers, and Physical Educators to comment on this blog and share their knowledge and methods that they use.