Bio-mechanical differences between adolescent male and female soccer players result in greater risk of serious knee injury.

Studies show girls who play soccer are anywhere from 2 to 8 times more likely than boys to suffer a non-contact tear to their Anterior Cruciate Ligament (ACL) while participating in their sport¹.  The injuries usually occur when the athletes make a sudden change in direction or while landing after jumping².  The greater risk-factors can, in great part, be attributed to the way hip and knee flexion, internal knee rotation and activation levels of the quadriceps and hamstring muscles interact in girls vs. boys.

A study conducted at Dalhousie University and published in the American Journal of Sports Medicine tested 42 healthy adolescent soccer players for bio-mechanical differences.  The participants were asked to perform a series of sports maneuvers including:  A straight run, a side cut following a straight run, and a cut across the body after a straight run. 

The results of the tests demonstrate bio-mechanical differences do exist between young male and female athletes.  Female athletes have greater muscle activation magnitudes in their gastrocnemius (upper calf muscle) and Rectus Femoris (one of the

quadricep’s muscles) muscles and a reduced hip flexion angle during cutting movements compared to their male counter parts.  However, hamstring activation magnitudes were shown to be about the same. The study also found differences in the joint movements including hip adduction, hip internal rotation, knee adduction, and ankle eversion during the first 20% of the cutting movement, the time when most ACL injuries occur².

Because of these differences, special care should be taken when designing strength training programs for young female athletes to avoid further increasing the magnitude of muscle activation in girls' quadriceps. Steps also should be taken to increase the magnitude of the hamstring muscles to help narrow the ratio between the two.  Attention should also be paid to lateral stability of the hip, knee and ankle to lessen the impact of hip rotation, knee inversion/eversion, and ankle flexion.  Finally, it is important to teach proper landing and cutting techniques to girls as they relate to their sports.  By paying attention to these details, based on the data in this study, you may be able to help reduce the risk of serious knee injuries in your young female soccer players.

Tom Dueber is the founding partner and a strength and conditioning coach specializing in programs for adolescent athletes at Canyon Performance Training.

Scott C. Landry, Kelly A. McKean,et al. Neuromuscular and Lower Limb Biomechanical Differences Exist Between Male and Female Elite Adolescent Soccer Players During an Unanticipated Side-cut Maneuver: Am J Sports Med. 2007; 35

1. Agel J, Arendt EA, Bershadsky B. Anterior cruciate ligament injury in national collegiate athletic association basketball and soccer: a 13-

year review. Am J Sports Med. 2005;33:524-530.

2. Boden BP, Dean GS, Feagin JA Jr, Garrett WE Jr. Mechanisms of anterior cruciate ligament injury. Orthopedics. 2000;23:573-578.

5 things Canyon Performance Training does differently for young female athletes to reduce injury risk and improve sports performance

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Young female athletes are 4 to 6 times more likely to suffer catastrophic knee injuries than their same-sport male counterparts¹.  There are many factors thought to contribute to the higher injury rate including: The way girls land after jumping, over development of the quadriceps as compared to the hamstring, and less lateral stability through the legs.  By understanding and addressing these factors Canyon Performance coaches reduce risk of injury by up to 50% in female athletes and increase sports performance without increasing muscle size or creating “bulk.” 

1. Teaching proper landing strategy: When landing after a jump, girls are less likely to properly flex at the knee and hip².  This poor landing strategy can lead to a tear to the Anterior Cruciate Ligament.  When working with girls we start with small jumping motions and teach them how to land with proper knee and hip flexion and increase to bigger and higher motions.  This technique can also lead to increased vertical jump height.  As the body develops the habit of bending properly at the hips and knees the athlete is better able to load and reload for a more explosive jumping motion.

2. By default girls tend to have highly disproportionate quadriceps to hamstring strength ratios².  The quadriceps are so dominant they can start to “overpower” the hamstring and gluteus maximus muscles making the athlete more susceptible to knee and ankle injuries.  We include hamstring and “Glute” specific exercises in all of our strength programs for girls.  These exercises strengthen and re-teach the muscles to fire in proper sequence.  By doing this, over time, the strength ratios decrease and the hamstrings and “glutes” start firing properly increasing lower body explosive power.

3. Canyon checks each female athlete for an “Anterior Pelvic Tilt.”  Anterior Pelvic Tilt, or APT simply means the front of the pelvis sits lower than the back of the pelvis. An easy way to check is to observe the front of the waistband vs the back of the waistband when the athlete is standing tall.  If the front of the waistband is lower than the back, there is APT.  The APT can indicate tightness in the hips and weakness in the Core and “glute” muscles and decrease overall stability in the hip complex.  Strengthening the Core and Glutes and stretching the front of the hips can help correct the tilt and may lead to less lower back and hip pain.  This also has the added benefit of increasing the athletes overall balance and power.
   

4. Female athletes tend to have less lateral hip, knee and ankle stability³.  During the single leg squat we can see if there is excessive lateral hip translation (hip sticks out to the side) or internal knee rotation, or valgus and a lack of hip and knee stability.  By doing corrective exercises to strengthen the hips laterally we can help reduce the chance for ACL injury and increase lower-limb power by achieving proper alignment.
   

5. Finally, Canyon evaluates all female athletes for ankle eversion and weak arches.  By increasing stability in the ankle we can help avoid ankle sprains and by strengthening the arch we can help reduce the occurrences and severity of shin splints.  Often times athletes are asked to play through minor ankle sprains and shin splints.  By helping to reduce the occurrences and severity of these injuries we can keep athletes performing at a high level through the duration of the season.

Tom Dueber is the founding partner and a strength and conditioning coach specializing in programs for adolescent athletes at Canyon Performance Training.

1. E.A. Arendt,J.Agel,R.Dick,Anterior cruciate ligament injury patterns among collegiate men and women ,J.Athl.Train.34(1999)86–92.

2. T.E.Hewett,K.R.Ford,B.J.Hoogenboom,G.D.Myer,Understandingand preventingACLinjuries:considerations – update 2010,NorthAm.J.Sports Phys.Ther.5(2010)234–251.

3. T.E. Hewett, G.D. Myer, Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes Am J Sports Med 2005 33: 492