Kids and Concussions: The effects of head injuries in young athletes
Three Part Series by the Star Ledger
January 04, 2010, 6:00AM
In the first of a 3-part series on concussions and their impact on youth sports, Star-Ledger staff writers Matthew Stanmyre and Jackie Friedman take a look at the effects of head injuries in young athletes, what New Jersey is doing and what more can be done to protect our kids.
Part 2: Every sport presents the danger of concussion — even cheerleading. Some cheerleaders from New Jersey still cope with the devastating effects of brain injuries suffered in practice and during competitions.
Part 3: A look at the steps schools and youth leagues in New
Jersey are taking to cope with brain injuries and other safety issues.
Preventing Knee Injuries in Women’s Soccer
By Wayne Nelson, DC, CCRS
The United States has recently seen a rapid increase in participation of young athletes with organized youth soccer leagues. As parents spend more time around the sport they become very familiar with the injuries associated with this sport. They begin noticing that lower extremity injuries are more common and that there are many more injuries associated with the women’s teams than the men’s, especially knee injuries. Although soccer has a low rate of injuries compared to other youth sports, current literature reports that the lower limb, specifically the ankle and knee, are the body parts most often injured in youth soccer.
Factors That Increase Your Risk Of An ACL Injury
The anterior cruciate ligament (ACL) is one of the major stabilizing ligaments in the knee. The majority of ACL injuries in sports occur in the absence of physical contact with other players at the time of injury and are categorized as non-contact ACL injuries. It has been shown that the female athlete involved in cutting sports (soccer, basketball and volleyball) is 4 to 10 times more likely to sustain a sports-related non-contact ACL injury than male athletes. Also, we know that the knee has a nearly sixfold increased risk of reinjury with a previous injury to a knee and the ankle has a fourfold greater risk of reinjury if the athlete had a previous ankle injury. A prior injury is one of the single best predictors of future injury risk and ACL injuries to the opposite knee are even more common than reinjuries of the initial knee.
Figure 1. ACL injuries typically occur immediately after a landing when the knee is nearly straight.
The Cost Of An ACL Injury Goes Beyond Dollars!
The cost of an ACL rupture is costly with conservative estimates of surgery and rehabilitation at $17,000 to $25,000 per injury. Additional costs include loss of entire seasons of sports participation, loss of scholarship funding, lowered academic performance, longterm disability, chronic knee instability, secondary damage to menisci and a 10-times greater risk of degenerative osteoarthritis of the knee.
Why Women Have More ACL Injuries Than Men
A variety of factors have been explored to account for the gender difference in susceptibility to ACL injuries: ACL size; knee joint laxity; standing posture, foot pronation (“dropped arch”), misalignment of the lower extremity, and pelvic position; and hormonal variations. Furthermore, they have explored shoe-surface interaction; playing surface; skill level; level of conditioning, muscle strength, and altered neuromuscular controls. With regard to environmental, anatomical and hormonal risk factors, there is no conclusive evidence that any one single risk factor correlates directly with an increase in ACL injury in female athletes. Therefore, the emphasis has turned to biomechanical risk factors and the use of neuromuscular and proprioceptive intervention programs to address potential biomechanical deficits.
Prevention Is The Best Solution
Preventing ACL injuries is paramount. ACL injury reconstruction surgeries are complicated for adolescents and often have poor results. On the other hand, the natural history of untreated ACL injuries in adolescents is not acceptable. Because of the concerns with surgical and nonsurgical treatments of ACL injuries in adolescents, ACL injuries are more devastating for adolescents than for adults, and the early training for prevention of noncontact ACL injuries in adolescents is important.
Inadequate Knee Control Causes ACL Injuries
Understanding injury mechanisms is a key component of prevention of non-contact ACL injuries. Mechanically, ACL injury occurs when an excessive tension force is applied on the ACL. A non-contact ACL injury occurs when a person themselves generates great forces at the knee that applies excessive loading on the ACL. This can occur in a number of ways: sudden deceleration, repeatedly performing landing and pivoting maneuvers (Figure 2), one-step/stop deceleration, cutting movements, sudden change of direction, landing from a jump with inadequate knee and hip flexion (at or near full extension), or a lapse of concentration (resulting from an unanticipated change in the direction of play).
Figure 2. A landing and pivoting maneuver.
ACL injuries typically occur immediately after landing during a deceleration maneuver combined with a change of direction while the foot is in a closed-chain position (planted on the ground). While the foot is planted and pronated (rolled in), the tibia of the lower leg is internally rotated (turned inwards), and the knee is nearly straight (at or near full extension. Figure 1). If the athlete attempts to change direction, the result is an excessive torsional force that can potentially strain or rupture the ACL.
Figure 3. A typical falling pattern that demonstrates an increased risk for an ACL injury.
How Long Has This Been Going On?
A longitudinal study of children 5 to 12 years of age in youth soccer demonstrated that there is no gender difference in knee injury risk before puberty in athletes. However, age older than 11 years was a significant risk factor for knee injury in girls. Compared to their male counterparts, changes that occur in the female athlete while performing a stop-jump task include: decreased knee and hip flexion angles at initial contact, a tendency to land with the lower extremities more extended, and they maintained knee valgus (Figure 4) at initial foot contact with the ground. The degree of these changes increased with age. The literature indicates that the ACL injury rate in adolescents increases linearly after 12 years of age and that adolescents at 17 and 18 years of age have the highest ACL injury rate.
Training for Prevention Also Helps Performance
Comprehensive training can lead to improvements in athletic performance and movement biomechanics as well as reduce ACL injury risk in female athletes. The processes that reduc ACL injury rates appear to be relatively similar, arising from a common rationale derived from performance enhancement training and physical rehabilitation for athletes. Improving Technique Is The Answer Emphasis of training should be on proper technique: landing softly, increase knee flexion, minimize knee valgus (align the center of knee cap with the first toe). Improving running technique to include accelerated rounded turns, decelerate with a multi-step stop, and maintain proper knee alignment and knee flexion during cutting maneuvers. Strength conditioning should focus on increasing hamstring, gluteus maximus, gluteus medius (hip extension and abduction) strength and reactivity.
Figure 4. Dynamic lower extemity valgus. To maximize stability keep the knee cap aligned with the large toe. (Hewett TE, et al. Am J Sports Med. 2006;34,2:299-311.)
About The Author
Located in Roseville, California, Wayne Nelson, DC, CCRS, is a board certified Chiropractic Rehabilitation Specialist and has over 17 years experience in rehabilitation, sports medicine and performance training. If you have any questions about preventing injuries or improving your fitness for soccer you can contact Wayne at ConditionForLife@comcast.net.
Figure 5. Important muscles of the thigh.
- H - hamstrings
- Gmx - gluteus maximus
- Gmd - gluteus medius
- Q - quadricps
Top 10 Ways to Prevent Soccer Injuries
By Brian Schiff
Soccer is a growing sport among the youth in our country today. Notably, more female athletes are choosing to play soccer. With this added participation, it is inevitable that more injuries will occur. Many of these injuries are linked to physical training and conditioning.
The most common injuries in soccer typically involve the ankle, knee and hip region. Such injuries include ankle sprains, knee ligament sprains, meniscus tears, and muscular strains (hip and groin). ACL injuries are now reaching epidemic proportions, especially in the female soccer athlete.
Research has indicated that proper training programs can and do reduce ACL injuries and will help prevent other sports related injuries. Much of the research has indicated that strengthening, jump landing technique and agility training affect the risk for this type of injury. The following list will outline how to effectively reduce common soccer injuries.
1. Perform a periodized year round strength training program with special emphasis on balancing the muscles of the leg and targeting the core muscles (low back, abdominals and hip).
2. Understand the energy systems utilized in soccer and train them according to performance demands. This involves the proper blend of training aerobic endurance and anaerobic power to ensure explosive performance over the entire course of a match. Fatigue late in the match can lead to injury.
3. Perform routine stretching to prevent muscular imbalance and tightness. This refers to static stretching that should be done after a suitable warm-up or at the end of practice.
4. Perform supervised, carefully planned plyometric (jump) training to teach proper landing form and develop power.
5. Incorporate dynamic balance training to teach body control and reduce ankle sprains and knee injuries.
6. Take planned periodic rests from practice and play to avoid overtraining.
7. Perform routine agility and quickness drills to improve footwork and cutting ability. Many ACL injuries occur with non-contact cutting movements and it is critical for athletes to cut on a bent knee and be able to control their momentum during change of direction.
8. Perform a dynamic warm-up prior to practice and games that effectively simulates sport specific movement. These activities will better prepare the body for the demands placed upon it during competition. This can be further broken down into general and specific functional warm-ups.
9. Perform yearly pre-season physical screening evaluations with an athletic trainer or physical therapist to assess any musculoskeletal areas of weakness.
10. Perform pre-season, in-season and post-season fitness testing to assess training methods, performance and conditioning. This protocol will allow the coaches to adjust training volume, intensity and modalities to ensure that their athletes are peaking at the right time and not training improperly.
All of these suggestions are important in developing complete athletes and preventing common injuries. They will not prevent all soccer injuries, however, they will greatly reduce the risk potential and enhance athletic performance. The ultimate key to injury prevention is understanding the sport of soccer and developing a program designed to address its demands on the body.
Brian Schiff, strength and conditioning coach for The Columbus Crew Major League Soccer Team, recently co-authored Protecting The Athlete’s Knee: A Complete Guide to ACL Injury Prevention and Athletic Excellence. For more information on his training programs, visit http://www.fitnessedgeperformance.com.
Preventing ACL Tears
The Anterior Cruciate Ligament is extremely important to the competitive athlete. This ligament controls rotational forces in the knee. If this ligament is torn, sudden changes in direction become nearly impossible. Prevention of injuries to the ACL should be part of every athlete’s training regime.
Statistically, participants in women’s basketball and soccer are at a higher risk to tear an ACL. There are many theories as to why females are more at risk for this injury. Some of them include: a narrower notch width of the femoral head; the relative strength and muscle recruitment pattern of the hamstring muscles relative to the quads; high levels of estrogen; and, lack of proper training at a young age. Most experts believe that the incidence of ACL tears can be lowered by instituting some simple changes in the training of not only female athletes but all athletes.
General sports training should be centered around a properly periodized strength, flexibility, and aerobic conditioning program. The program should be planned so that the athlete progresses through specific phases of conditioning culminating in peak performance at the end of the sport season. The goal should be for the athlete to peak physically and mentally for the playoffs. The three basic cycles are: pre-season preparatory cycle; in-season cycle; and post-season cycle.
Coordination Improves Performance
Neuromuscular control of the knee during athletics is maintained by a complex interaction of the quadriceps and hamstring muscles. This includes both the muscles and the nerves that trigger the muscle contraction. Due to this non-contact ACL injuries may be a result of a breakdown in, or the lack of, the neuromuscular recruitment patterns necessary to prevent undue stress on the ACL.
The balance of power and the recruitment pattern of the quads and hamstrings have been shown to prevent ACL injuries. The quad muscles are an ACL antagonist, that is they place stress on the ACL when contracting. The hamstrings are an ACL agonist, removing ACL stress when contracting.
Due to this, if the hamstrings are excessively weak or inflexible they may not adequately protect the ACL during a strong quad contraction. Also, if the quad group is excessively strong, relative to the hamstrings, the ACL may be torn due to a lack of hamstring “protection.” ACL injury prevention should then focus on a balance in strength between the hamstrings and quads. It is recommended that the hamstrings should be 60 - 80% as strong as the quads. Also, proprioceptive exercises should be utilized to improve the neuromuscular recruitment patterns of the quads and hamstrings.
The off-season strength program should focus on the exercises that result in increased hamstring strength and flexibility as well as coordinative jumping exercises (plyometrics). During the first few weeks of training the emphasis should be on teaching proper jumping and landing techniques. The athletes should be taught to land on the balls of the feet with the knees flexed and the chest over the knees. They should be constantly reminded to avoid any excessive side-to-side or forward-to-back rocking of the knees upon landing. Valgus (inward) movement of the knee upon landing should also be discouraged. The athlete should also be taught how to land “softly.” This type of landing occurs when the athlete lands on the balls of the feet then rocks to the heels. Proper back posture should also be reinforced verbally.
Verbal cues should be used when observing the athlete during the jumps. Statements such as “light as a feather,” “recoil like a spring,” and “straight as an arrow” should be used to reinforce proper body mechanics. Proper body mechanics are the goal in the early stages of this type of program. Emphasis on power and explosion should only be instituted after the athlete performs the jumps properly.
Weight room activities should focus on exercises that improve hamstring strength and coordinated firing with the quad muscle group. Examples of these types of exercises are: hamstring curls, squats, power cleans, and dead lift. As with the plyometric exercises, proper technique should be taught prior to increasing the load. Be sure that the athlete’s hamstrings are 60 - 80% as strong as the quad muscles; that is, if the athlete can perform a 1-leg knee extension with 100 pounds they should be able to do a 1-leg hamstring curl with 60 - 80 pounds.
Examples of plyometrics can be found by following this link