Dynamic Chiropractic Canada – April 1, 2014, Vol. 07, Issue 04

Chiropractic's Role in Sports-Related Concussion

By Michelle Laframboise, BKin (Hons), DC, FRCCSS(C)

Sports-related concussion has gained popularity by media in much recent years due to the debilitating symptoms and the potential for long-term sequelae if not managed properly by a medical professional. Sports-related concussion injuries are not limited to professional athletes and sport these injuries are inherent to any level of sport participation or athletic level.

Practitioners that manage athletes of all levels turn to the International Consensus Conferences on Concussion in Sport for updated information on concussion management. The consensus conferences are specifically based on the deliberations from multiple practitioners on how to manage sports-related concussion. The latest International Conference on Concussion in Sport was held in Zurich, November 2012.1

There has been much discussion over the years regarding the definition of concussion and how it is related to or separate from the definition of a mild traumatic brain injury. The Zurich 2013 guidelines for concussion in sport there was acknowledgment from the group that the two terms; concussion and mild traumatic brain injuries are at times used interchangeably, along with commotio cerebri. However, it is important to note that concussion is a subset of mild traumatic brain injuries.1

snowboarding - Copyright – Stock Photo / Register Mark What Is A Concussion?

Concussion is defined in the updated consensus conference as "a complex pathophysiological process affecting the brain, induced by biomechanical forces."1 It can be caused by a direct blow to the head, face, neck or anywhere on the athletes body from an impulsive force that transmits the force directly up to the head.1 This force to the head or elsewhere on the body results in an abrupt acceleration and/or deceleration of the cranio cervical complex.1,2,3

When there is an abrupt acceleration and/or deceleration to the cranio cervical complex it may result in a concussion, which will typically result in a rapid onset of short-term impairment of the athletes' neurological function that usually will resolve spontaneously. However, there are cases of concussion where signs and symptoms evolve over minutes to hours after the initiation of a blow.1

Signs and Symptoms of Concussion

The specific signs and symptoms of a concussion can vary significantly from athlete to athlete. The clinical symptoms of a concussion may or may not involve a loss of consciousness. The signs and symptoms of concussion have been broken down by the American College of Sports Medicine in the third consensus statement as cognitive, somatic, affective and sleep disturbances.

Cognitive involves the following; confusion, amnesia, loss of consciousness, disorientation, feeling "in a fog", vacant stare, inability to focus, delayed verbal and motor responses, slurred or incoherent speech and excessive drowsiness. Somatic involves the following; headaches, dizziness, balance disruption, nausea/vomiting, visual disturbances and phonophobia. Affective involves the following; emotional lability, irritability, fatigue, anxiety and sadness. Finally, sleep disturbance signs and symptoms involve trouble falling asleep, sleeping more than usual, sleeping less than usual.2,3

There are no structural changes to the neurological system after a concussion. The major neuropathological changes reflect a functional disturbance in the brain. Therefore, standard structural neuroimaging studies are rendered useless because the concussion cannot be visually seen on the images suggesting the functional neural dysfunction be caused by cellular apoptosis.1 The rapid short-lived nature of the neurological impairment from a concussion most commonly (80-90%) will spontaneously resolve within 7-10 days.1

Biomechanics of Impact

Concussion is due to an abrupt linear and/or rotational acceleration and/or deceleration to the brain as it sits within the skull for protection.3 There has been a lot of discussion over the years on whether this extreme amount of acceleration and/or deceleration of the brain can also result in cervical spine injuries.3,4 Thus, a hypothesis has been formed that cervical spine strength may actually decrease the risk of concussion.

Royal College of Chiropractic Sports Sciences (Canada)chiropractic sports resident out of Toronto, Ontario, and the founder of Compete Concussion Management, Dr. Cameron Marshall says: "It may not be that simple. Most concussions are caused when the person is not ready for the hit that is coming. Research has also shown that the peak acceleration of the head occurs between 6-20 ms after impact, however it takes roughly 150 ms to even begin contraction of the cervical spine musculature and another 150 ms to reach 50% of the maximum contractile abilities."

He believes being aware of an impending hit in advance with enough time to contract the cervical spine musculature that is responsible for stabilizing the neck may be a potential preventative strategy for concussion.3

Pathophysiology of Concussion

Dr. Cameron Marshall of the RCCSS(C) summarizes the pathophysiology of concussion in his latest article in the JCCA entitled Sports-related concussion: a narrative review of the literature. Due to the rapid acceleration and/or deceleration of the bran after a blow to the head or elsewhere in the body there is a sudden mechanical elongation and shearing of the neurons in the brain.3,5,6,7

energy mismatch - Copyright – Stock Photo / Register Mark Reprinted with permission from Marshall C. Sports-related concussion: A narrative review of the literature. J Can Chiro Assoc 2012; 56(4). If there is a brief loss of consciousness it is coming from the shear forces that are acting on the neurons causing a transient neuronal disruption. This mechanical neuronal deformation can cause depolarization of neurons via opening ion-regulated channels in the brain. The depolarization of the cell allows for the release of glutamate, an excitatory amino acid. The glutamate allows for more potassium to be released from the channel, which will further depolarize the cell.

Furthermore, this depolarization will then activate N-methyl-d-aspartate (NMDA) receptors. This will then allow an increase in calcium into the cell, which may have damaging effects. Large quantities of calcium ions in the cell will cause mitochondrial dysfunction causing a uncoupling of the oxidative phosphoylation within the electron transport chain decreasing the amount of ATP that is generated and leads to an increase in reactive oxygen species.

The reactive oxygen species are responsible for the irreversible cellular death due to the inability to detoxify them. Also, the increase in calcium can be responsible for cellular damage causing a disruption in neural connectivity. This is the cascade that is responsible for the widespread transient signs and symptoms of a concussion because there is an ionic imbalance that requires maximum ATP levels to restore the normal homeostasis.3,5,6,7,8

Furthering in the signs and symptoms of a concussion is the fact that there is a increase in glucose demand because the nerve cells are forced to rely on anaerobic means of energy production, which is less efficient. There is further demand for more ATP because there is known to be a decrease in cerebral blood flow after a head injury. Thus, the ATP is being used more than it can be made creating an energy imbalance.3,7

Diagnosis of Concussion

The diagnosis of concussion is not easy and requires a high level of clinical suspicion and knowledge on the topic. Despite the advancement in concussion research and the standardization of sideline assessments, young athletes are at risk for mis-diagnosis, which could cause serious long-term effects to the brain.

The diagnosis of an acute sports-related concussion involves the assessment of clinical symptoms, physical signs, cognitive impairment, neuro behavioral features, sleep disturbance and a detailed concussion history1. The initial examination should consist of the Sideline Concussion Assessment Tool 3rd Edition (SCAT3) as well as a full neurological examination, cranial nerve examination and cerebellar examination. The evaluation of an athlete should be on the sideline by a licensed healthcare provider using standard emergency principles paying close attention to ruling out cervical spine injury. The athlete needs to be removed from play immediately. The most common symptoms in concussions are headache, dizziness, difficulty concentrating, confusion, visual disturbances. Loss of consciousness in not common in concussion but is possible, however, it does not increase the severity of the outcome.

Chiropractic Scope of Practice

Chiropractors have the training to identify and manage concussions. A sports specialist chiropractor is highly trained in up to date information on diagnosis, management and returning athletes to sport after concussion. However, if a patient presented with a concussion that, in the opinion of the practicing chiropractor, went beyond their scope and/or competency level to manage, they would be required to advise the patient to consult with another healthcare professional.

Co-management with the patient/athletes physician or sports physician is good practice. Concussions are extremely complex injuries that may potentially lead to long-term sequelae including brain damage if not managed properly. It is also very important to understand the role of ruling out more sinister diagnoses such as; epidural/subdural hematomas, hemorrhages and aneurysms to name a few. Please make sure you are highly trained in concussion management when dealing with concussion patients.

Chiropractors are urged to stay within their scope of practice when managing athletes with concussion and to refer to a more qualified healthcare professional if there is lack of confidence. The management of concussion is centered around complete physical and mental rest until the acute symptoms resolve and then a graded return to physical exertion prior to medical clearance to return to play.1 No athlete should return to play the same day as a suspected concussion.

Return to Play Guidelines

Initial management includes a period of at least 24 hours complete mental and physical rest; refraining from television, reading, video games exercise and school. These are some additional tips to recommend to your patients as well:

  1. Light aerobic exercise is recommended to increase heart rate.
  2. Sport-specific exercise to add movement to increased heart rate.
  3. Non-contact training drills to add coordination and cognitive load-challenging multiple systems to the exercise.
  4. Full contract practice to restore confidence and assess functional skills.
  5. Return to normal play/sport.

Each of these six stages is to take at least 24 hours. If any symptoms are incurred at any of the stages, the athlete is to rest for the remaining day and return to the previous stage the following day. All stages are 24 hours.1

Serial monitoring of the athlete of >2 hours post concussion is recommended for repeat neurological assessment to look for improvement or deterioration of condition. There is consensus that the most important tests to pay attention to are the cognitive testing, cranial nerve examination and balance testing. Conventional neuroimaging (CT/MRI) as stated are not able to detect a concussion; however they are useful in examining for focal brain damage and intracranial hemorrhage.1

Further, "severe or worsening of headache, seizure, two or more episodes of vomiting, unsteady gait, slurred speech, weakness or numbness in extremities, or Glasgow Coma Scale of less than 15 indicate a need for prompt referral to the emergency department for neuroimaging."1

Chiropractors can be very helpful in the management of cervical spine pain commonly associated with concussion.

Complete Concussion Management

Complete Concussion Management (CCM) is a multidisciplinary network of healthcare practitioners across Canada, specifically trained in the diagnosis, management, and treatment of concussion injuries and post-concussion syndrome. This evidence-based program educates various healthcare practitioners including physicians, chiropractors, and physiotherapists on the physiology, pathology, and management of all spectrums of concussion injuries from the acute to the chronic as well as chronic traumatic encephalopathy. CCM is involved with numerous amateur sports organizations and school systems in an effort to provide comprehensive and evidence-based concussion management programs, typically only seen in professional sports, to athletes of all ages and skill-levels.

The RCCSS(C) has an associate partnership with Concussions Ontario (concussionsontario.org). Concussions Ontario is a concussion/mild traumatic brain injury (mTBI) strategy aimed at improving the recognition, diagnosis, and management of concussions in Ontario. This strategy is sponsored and led by the Ontario Neurotrauma Foundation in collaboration with many organizations such as the Canadian Medical Association, Ontario College of Family Physicians, and the Canadian Association of Physical Medicine & Rehabilitation.


  1. McCrory P., Meeuwisse WH., Aubry M et al. Consensus statement on concussion in sport: the 4th international conference on concussion in sport held in Zurich, November 2012. Br J Sports Med 2013; 47:250-258.
  2. Herring SA, Cantu RC, Guskiewicz KM, Putukian M, Kibler WB, Bergfeld JA, et al. Concussion (mild traumatic brain injury) and the team physician: a consensus statement – 2011 update. Medicine & Science in Sports & Exercise. 2011; 2412–22.
  3. Marshall C. Sports-related concussion: A narrative review of the literature. JCCA 2012; 56(4):299-310.
  4. Viano DC, Casson IR, Pellman EJ. Concussion in professional football: Biomechanics of the struck player-Part 14. Neurosurgery. 2007;61(2):313-28.
  5. Khurana VG, Kaye AH. An overview of concussion in sport. J Clinical Neuroscience. 2012;19(1):1–11.
  6. Signoretti S, Lazzarino G, Tavazzi B, Vagnozzi R. The pathophysiology of concussion. PM&R. 2011;3(10):S359-68.
  7. Giza CC, Hovda DA. The neurometabolic cascade of concussion. J Athl Train. 2001;36(3):228–35
  8. Ropper AH, Gorson KC. Concussion. N Engl J Med. 2007;356(2):166–72.

Dr. Michelle Laframboise is a sports fellow with the Royal College of Chiropractic Sports Sciences and is currently serving as chair of the public health committee. In addition to treating professional, Olympic and recreational athletes in practice at Back to Function in Orillia, Ontario, she has served as medical staff for provincial and national soccer clubs, figure-skating competitions, mountain bike competitions, wrestling and Taekwondo competitions. She has served as medical manager for the Ontario winter and summer games, as well as currently serving as team doctor for a junior 'A' hockey team.

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