The Centers for Disease Control and Prevention (CDC) defines mild traumatic brain injury (MTBI) – which is used interchangeably with the term concussion – as a complex pathophysiologic process affecting the brain, induced by traumatic biomechanical forces secondary to direct or indirect forces to the head. A concussion or MTBI can be caused by a blow or a jolt to the head or body that disrupts the function of the brain.
There are methods for lowering the risk and reducing the number of sport-related concussions across America. Some of the factors are return to play, rules changes, the number of exposures, skill development, protective equipment and strength training to lower subconcussive forces. All of these considerations play a part in abatement of concussion. Exclusion of any one item affects the safety of the student-athlete. Each factor must be reviewed by the professional who, by using assiduity and diligence, can and will have a positive impact on risk.
Preventative sports medicine is the hallmark of any strength and conditioning program. The first goal of a professional is to develop effective and practical ways to reduce the number of sports-related injuries.
In the 1970s, collegiate programs began introducing strength training into their athletic programs to enhance performance as well as reduce injuries. There was very little research on the subject of weight training and athletics and many misnomers about strength training in general. At the time, the majority felt strongly that the use of barbells and strength training devices would inhibit athleticism by bulking and stiffening the athlete. Women, in general, had a strong fear of becoming too muscular. Educators worked to dispel those fears and strength and conditioning programs are now commonplace throughout athletics. Though some wrongly conceived beliefs still linger today when it comes to training the musculature associated with the cervical spine.
The benefits of muscular development are far greater than initially purported since the inception of strength training into intercollegiate athletics. One of the important functions of strength training has become the development of the muscle and tendon as a unit. The muscle-tendon unit attenuates and dissipates force. Developing a strong musculoskeletal system is what is needed to protect joints and reduce injuries. This attenuation and dissipation of force is not exclusive to particular joints in the anatomical system.
Dawn Comstock, associate professor of epidemiology at the Colorado School of Public Health, collected data on 6,704 student-athletes in six sports: boys' and girls' soccer, basketball and lacrosse. Her results indicated that for every pound of improved neck strength, an individual reduces his or her concussion risk.
Dr. Comstock from her years of injury surveillance points out the primary mechanism for concussion injury is athlete-to-athlete contact. The researcher then asked, "Did the athlete see the blow coming?" And she found that for the athletes who saw the blow coming – those who had a chance to activate their neck muscles – experienced less severe concussion.
The attenuation and dissipation of force and bracing before impact by activating neck muscles can lower subconcussive trauma. This is a great reason for training the musculature that moves the neck and supports the head.
There are many more reasons for an athlete to train this region of the anatomy. ‘Where the head goes the body will follow’ is an athletic axiom that coaches teach. Stand straight, place your fingers lightly on the nape of your neck. Without moving your head quickly move your eyes left and right. You will feel the musculature in your neck begin to contract. The eyes are not connected to the neck muscles but the brain is preparing the body for movement. Like our limbs it is important to move the head quickly. Training the head and neck will enhance performance.
The respiratory system’s process of inspiration and expiration involves much more than the diaphragm and the internal and external intercostal muscles. The scalene muscles in the neck are involved in almost every breath we take. The platysma and sternocleidomastoid are involved in heavy breathing (See Figure 1). Injure or develop neck muscles and your body’s athleticism will be affected.
Conventional wisdom suggests that strength training increases body mass index (BMI) in a positive way, but does it? BMI is a simplistic measure of body fat. It is calculated by dividing one’s weight in kilograms by the square of one’s height in meters. The derived results can then be compared to a chart of normative data provided by the National Institutes of Health (NIH). BMI is useful for the overweight and obese, yet it does have limitations. BMI may overestimate body fat in athletes and others who have muscular builds. The problem is this simple tool does not differentiate between fat mass and lean body mass. It has long been argued that heavily muscled, weight-trained athletes are healthy despite their BMI classification.
At issue is the athlete that increases muscle mass and vascularity significantly in all areas of the body but the neck region alters peripheral vascular resistance in an acute way. Peripheral resistance is a function of the internal vessel diameter, vessel length and blood viscosity. Having a large body and an undeveloped neck changes the force of the delivery system’s blood flow to the head.
The cervical spine’s associated musculature is regarded as an important proprioceptive organ for postural processes. The muscles are small with a high spindle density. You can think of this region as the hotbed of proprioception. Disturbances of gait can occur by interfering with, damaging, weakening or fatiguing the muscles of the head and neck. Training this region augments static as well as dynamic posture – our ability to balance.
The head and neck muscular system is a complex anatomical structure and has apparent muscle redundancy; that is, more head and neck muscle than degrees of freedom. It is been postulated that individuals exhibit a large variation of neck muscle activation strategies for accomplishing the same task intra individually, as well as between subjects. The health practitioner’s return-to-play protocol after a concussion, whiplash, nerve or muscle trauma must contain a measurable strength component to restore each muscle to normalcy, redressing this tendency to substitute by the injured athlete.
Head and neck muscles can be thought of as two distinct muscular units, the musculature that moves the head and the muscles that move the cervical spine. Each unit must be trained to maximize development and ongoing strength values collected. This aids in overall muscular fitness and post injury assessment in returning a student-athlete to their appropriate functional movement.
Injuries to the mouth, face and jaw are part of sport. Having a strong jaw helps in bracing, clenching against a mouth guard, and resisting the pull of the chin strap in helmets. Injured masseter muscles, strained temporalis, pterygoids, digastrics all must be rehabilitated and strengthened when damaged (See Figures 2 and 3).
To help lower subconcussive forces, protect the student-athlete returning to play, maximize performance and fitness, strength training of the head, neck and jaw must be inclusive when designing exercise programs.
· Sean Gregory Neck Strength Predicts Concussion Risk, Study Says Time Sports 02.21.2013.
· Robert Nash, Angus Barnett, Sally Burrows, Warren Andrews, Brendyn Appleby Can a specific neck strengthening routine reduce cervical spine injuries in a Men’s Professional Rugby union team? A retrospective analysis Journal of Sports Medicine 2013 12,542-550
· Paul Steinbach Sports Injury Expert Dawn Comstock Talks Concussion Prevention Athletic Business; Apr 2013, Vol. 37 Issue 4, p11
· Beeman SM, Kemper AR, Madigan ML, Duma SM Effects of bracing on human kinematics in low-speed frontal sled tests. Ann Biomed Eng. 2011 Dec;39(12):2998-3010
· Bose D, Crandall JR., Influence of active muscle contribution on the injury response of restrained car occupants. Ann Adv Automot Med. 2008 Oct; 52:61-72.
· Vaccaro AR, Klein GR, Ciccoti M, Pfaff WL, Moulton MJ, Hilibrand AJ Watkins Return to play criteria for the athlete with cervical spine injuries resulting in stinger and transient quadriplegia/paresis.Spine J. 2002 Sep-Oct;2(5):351-6.
· Anita N. Vasavada, Barry W. Peterson, Scott L. Delp, Three-dimensional spatial tuning of neck muscle activation in humans Exp Brain Res (2002) 147:437–448.
· Thomas J. Roberts and Emanuel Azizi The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions, Journal of Applied Physiology August 1, 2010 vol. 109 no. 2 396-404.
· Armstrong B, McNair P, Taylor D., Head and neck position sense. Sports Med. 2008; 38(2):101-17.
Written by: Mike Gittleson
Appeared originally in NCAA.org