Although spine injuries may be among the least common of injuries encountered in athletes, they can be the most catastrophic. These injuries not only result in loss of playing time, but have the potential for significant long-term disability. Proper field-side and prehospital management will help minimize the severity of these injuries. Prevention of these injuries through proper coaching and enforcement of sport-specific rules to minimize maneuvers that place athletes at risk remains the most effective method of minimizing the consequences of these injuries.
Several sports have been identified as placing participants at an increased risk of spinal injury including football, ice hockey, gymnastics, rugby, skiing, snowboarding, and equestrian sports. Flexion and axial loading of the cervical spine has been implicated in the majority of the cases [1–3,4•].
Injuries to the thoracolumbar spine are sport specific. Disk degeneration resulting from repetitive flexion and extension is seen in gymnastics, herniation of the nucleus pulposus with lumbar flexion, axial compression, and rotation of the lumbar spine is seen in collision sports, and repetitive hyperextension occurring in football linemen, weight lifters, and gymnasts is associated with posterior element overuse injuries and spondylolysis. Acute thoracolumbar spine fractures usually require severe trauma and are uncommon in most athletes.
Despite having a lower rate of spinal injuries, football is associated with the largest total number of catastrophic spinal injuries due to its large number of participants. It is associated with the greatest number of catastrophic injuries of all sports, but the incidence of injury per 100,000 participants is higher in both gymnastics and ice hockey. Sporting events such as these are the fourth most common cause of spinal cord injury behind motor vehicle accidents, violence, and falls. According to the National Spinal Cord Injury Statistical Center, sports activities account for approximately 7.5% of all spine injuries since 1990 .
Proper field-side management of spinal injuries requires pregame preparation to insure the appropriate equipment is available. Management of the spine-injured athlete should include the following equipment: reflex hammer, spine board, hard cervical collar, 18-gauge spinal needle, screwdriver, anvil pruner or wire/bolt cutters, sharp knife, and an oral or nasal airway.
Before an injury occurs a team leader should be appointed. Ideally this individual is a physician or certified athletic trainer. When an injury occurs the team leader supervises all aspects of the field-side management of the athlete and designates responsibilities as needed. Communication between all parties involved in the care of the patient is crucial. The team leader should have a prearranged network for referral and emergency care. Furthermore, emergency contact phone numbers for each athlete should be available.
In any player with a suspected head or spinal injury, the first rule is to “Do No Harm.” All personnel, players, trainers, coaches, and parents should be instructed not to move an injured athlete. Any unconscious or confused athlete is assumed to have a cervical spine injury. The most important objective of the initial on-field examination is to make an accurate diagnosis of the athlete's level of consciousness and to rule out the presence of associated injuries, particularly to the cervical spine. Initial assessment begins as the certified staff is approaching the downed athlete. The examiner should observe the posture of the athlete and note any spontaneous motion and verbalization. Total lack of motion signifies loss of consciousness or a cervical spine injury. The examiner should begin with a simple question such as “Are you okay?” or “Are you hurt?” The athlete's response begins to establish the level of consciousness and Glasgow Coma Scale rating, and provides a primary survey of the athlete's airway, breathing and circulation (ABCs).
After stabilization of the ABCs, the athlete's level of consciousness dictates the on-field management. If an athlete is conscious and a spinal cord injury has been excluded, the examiner should perform a quick, comprehensive neurologic examination. The Glasgow Coma Scale (range 3–15), which evaluates eye opening, verbal response, and motor response, can quantify the level of consciousness and evaluate for a potential head injury. A grade of 11 or higher on the coma scale is generally associated with an excellent prognosis for recovery. A score of 7 or less is considered serious [6,7]. This assessment is followed by quickly addressing the specific symptoms. The most common cervical spine injury in football players is a neuropraxia of the nerve root or brachial plexus, commonly referred to as stingers or burners. Stingers or burners are caused by compressive or traction injuries to the nerve roots or the brachial plexus. Typically, the athlete presents with unilateral upper extremity muscle weakness and pain, with a full pain-free active range of motion of the cervical spine, and no tenderness to palpation. This particular presentation does not require spine precautions. However, the presence of these symptoms in both upper extremities suggests a spinal cord, rather than a nerve root or plexus, injury and one should proceed with caution . If an athlete has an altered level of consciousness, spinal precautions must be instituted. The first spinal precaution is to instruct all personnel not move the injured athlete.
If the athlete is conscious and spontaneously breathing, simply remove the mouth guard if present, and maintain the airway. Question his or her orientation to time, place, and person in the position in which he or she is found. Once orientation has been established and a cervical spine injury has been excluded, the athlete can be questioned and specific symptoms can be addressed. If the athlete is cooperating appropriately, a thorough neurologic examination should be performed. Once the athlete has been stabilized, a secondary survey thoroughly evaluating the neurologic and musculoskeletal systems should be performed, noting pupil responses, unusual posturing, flaccidity, rigidity, weakness, sensation, reflexes, and cranial nerve responses.
Any face-down unconscious or confused athlete is assumed to have a cervical spine injury and requires a controlled log roll. The first step is to immobilize the head and neck by supporting them in a neutral position. A neutral position restricts movement of a potentially unstable vertebral column and is an attempt to prevent further damage to the surrounding neurologic structures. A hard cervical collar may be applied to any athlete who is not wearing a helmet or shoulder pads.
Hard cervical collars provide excellent cervical stabilization in nonhelmeted athletes. However, the use of a hard collar in the helmeted athlete has few indications. Several studies have demonstrated that cervical collars in helmeted athletes (football, ice hockey, lacrosse) result in an improper fit and are often difficult to position secondary to interference of the helmet, shoulder pads, and attached neck roll/collar [8,9••]. Furthermore, attempting placement of a cervical collar in this situation will cause unnecessary manipulation of the head and neck. Manual stabilization of the cervical spine can be achieved by applying gentle traction using the crossed-arm technique. In this technique the examiner kneels at the head of the athlete and applies traction by grasping the sides of the athlete's head. The examiner's arms are initially crossed such that if the athlete is log rolled, the examiner's arms will end up straight (Fig. 1). After the cervical spine of a prone athlete with an altered level of consciousness is stabilized, the usual protocol of checking ABCs should be followed.
If the athlete is lying prone and is conscious and stable, the logroll should be delayed until a backboard or scoop stretcher is available. This will avoid moving the athlete a second time. The chances of a secondary injury increase with each movement. In this case, simply maintain the athlete's head and neck in the position that it was found until it can be properly stabilized as described above. With the head and neck stabilized, the athlete is log rolled directly onto the spine board. If the athlete is not stable or breathing adequately, he or she should be logrolled as soon as the cervical spine is stabilized and a coordinated team can be assembled.
Properly log rolling the patient is best performed with a minimum of four people. Large or heavy patients may require five or six people. The team leader at the head is in charge and maintains the position of the head and neck while giving every command. It is critical that the team strictly follows the orders of the team leader at the athlete's head to avoid compromising the position of the neck. Three other assistants should be positioned at the shoulders, hips, and lower legs of the athlete (Fig. 1). If available, the athlete should be log rolled directly onto a spine board. The three assistants ensure that the shoulders, hips, and legs are maintained in alignment with the head and neck during the log roll. The athlete should be log rolled toward the examiners. It is too difficult to maintain the rate of the log roll if the athlete is rolled away from the examiners. The athlete's arms should be positioned straight along his or her sides and the legs should be placed straight for the log roll. The team leader should use the crossed-arm technique that allows one's arms to unwind as the other examiners roll the athlete onto the spine board [10•].
Once the athlete is supine and the neck stabilized, he or she should be reassessed for the ABCs and appropriate resuscitation initiated as necessary. Special circumstances apply to any athlete wearing a helmet, shoulder pads, or other protective gear. All protective gear should remain in place including the shoulder pads and helmet. The helmet should not be removed. Removing the helmet while leaving the shoulder pads in place can hyperextend the neck causing further injury, and therefore should be avoided. The facemask should be removed as quickly as possible in any athlete wearing a helmet suspected of spinal injury, even if the athlete is conscious and breathing adequately. Clearly, if the athlete is not breathing adequately, prompt removal of the facemask will be necessary for resuscitation.
It is not recommended to wait until the athlete stops breathing before removing the facemask, because at that point time has become much more critical. Removing a facemask can be difficult depending on the type of helmet and if the helmet is old or rusted. It is important to evaluate what type of facemasks the athletes are using and how they can be removed prior to any injury. The appropriate tools should be readily available and the clinician should be familiar with the updated equipment. Most football, hockey, and lacrosse facemasks are secured to the back portion of the helmet with plastic or cloth loop straps that can be cut. A sharp blade may work, but this may result in increased risk to the examiner as well as the athlete. Multiple cutting tools, such as the Trainer's Angel (Riverside, CA), Face-Mask Extractor (Sports Medicine Concepts, Geneseo, NY), or wire/pipe cutters, have been successfully used, although these tools often require specific techniques for their use. Standard screwdrivers can be very effective, but their use can be complicated by rusted screws, or nuts that spin inside the helmet, therefore they are not recommended as a first-line tool. An anvil pruner, commonly used for gardening, has been shown to be the most efficient tool for the removal of most loop straps on facemasks. Regardless of which tool is chosen, studies have demonstrated that the choice of equipment is less important than the expertise of the personnel with a particular tool [11–14].
After releasing the lateral loop straps, many facemasks can be retracted or swung away. In most circumstances, this is not recommended because it may result in unnecessary head and neck movement and can interfere with resuscitation efforts. All loop straps of the facemask should be cut and the facemask should be entirely removed from the helmet. Some facemasks may be attached with metal snaps. It is often preferable to cut the straps rather than attempt to unsnap a metal snap that may be rusted. The helmet, chinstrap, helmet check pads, and all other gear should remain in place during facemask removal .
Removing the facemask is best accomplished with two people. The team leader continues to maintain the stability of the head and neck by applying gentle traction while a second rescuer cuts the appropriate loops on the facemask. Cutting tools should be directed away from the athlete's face and jarring movements avoided.
Practicing facemask removal is particularly important since the design of helmets has changed, and a method that was previously effective may be more difficult with new helmet designs. The new Riddell (Chicago, IL) football helmet secures the facemask with a plastic clip that cannot be easily cut and often requires removal with a screwdriver. The Cra-Lite (Riddell) facemask is a solid plastic facemask that is secured with four lateral loop straps. This particular model often requires removal with a PVC pipe cutter. Therefore, it is important at the start of each season to evaluate the design of helmet being used and practice facemask removal.
Once the facemask has been safely removed, ABCs are again re-evaluated. The mouth guard may be removed if it is still present. The chin straps, helmet, and shoulder pads should remain in place. If breathing is not present, the jaw thrust maneuver is the safest way to restore an airway without moving the neck. The jaw thrust maneuver is executed by grasping the angles of the athlete's mandible and lifting with both hands, displacing the mandible forward, while tilting the head back slightly. A head tilt-jaw lift maneuver may be required if the jaw thrust fails to provide an adequate airway or if the athlete is wearing an obstructive helmet. In this case, the fingers of one hand are placed under the central jaw near the chin and the mandible is lifted forward, while the head is gently tilted back. The second hand is placed on the athlete's forehead to provide stability and to assist in tilting the head back. Both of these maneuvers must be performed with care to avoid over-extending the neck.
Once stabilized in the supine position, it will be necessary to transfer the athlete to a spine board if this was not accomplished during the log roll. The Inter-Association Task Force for Appropriate Care of the Spine Injured Athlete [16•] recommends a minimum of eight people, if possible, to perform the lift. As per all of the previous maneuvers the team leader stabilizes the head and neck and directs the procedure. For this maneuver the team leader's hands are placed on the athlete's shoulders, under the shoulder pads if present. His or her thumbs should be pointed away from the athlete's face. The athlete's head should be stably cradled between the examiners forearms. Three people are positioned on each side of the athlete: one on each side of the chest, pelvis, and legs. The eighth rescuer prepares to slide the spine board under the athlete from the legs, once the athlete is lifted. At the team leader's command, the six lifters slide their hands under the athlete and equipment grasping the opposing person's forearm if possible to provide a firm grip and coordinated lift. At the team leader's command the athlete is lifted 4 to 6 inches off the ground while the spine board is slid into place from the feet. The position of the athlete should be strictly maintained in a coordinated fashion until the team leader gives the command to lower the athlete onto the spine board in a uniform coordinated fashion. Large athletes may require an additional person on each side to assist with the lift. The Inter-Association Task Force [16•] does not recommend using less than two people on each side even with small light athletes because it can be difficult to maintain proper alignment of the chest, pelvis, and legs, while sliding the spine board in from the feet.
There are several indications for which it may be preferable to log roll a supine athlete onto a spine board rather than lifting the athlete. Heavy athletes may require too many people to lift him or her safely, and broad athletes may be difficult to lift while keeping the entire spine stable. In addition, log rolling large athletes can be accomplished with five people whereas lifting may require eight people. Finally, the team may be more familiar with log rolling techniques than lifting techniques. There are no current studies comparing the two methods of inserting the spine board under the athlete. The team leader should choose whichever method he or she feels will maintain stable spinal alignment while expeditiously getting the athlete onto the spine board, taking into account the experience and strength of the assistants.
If the athlete is going to be log rolled onto the spine board from a supine position, the same technique that is used for log rolling from a supine position should be followed with one exception. The assistants are positioned at the athlete's shoulders, hips, and legs as before, however this time they roll the athlete away from themselves, hold the athlete slightly elevated while the spine board is inserted from the feet, and then gently roll the athlete back down toward themselves. The team leader stabilizes the head and neck while giving all commands as before.
Once the athlete has been placed on the spine board, she or he should be immobilized for transport. The head, which should remain in the helmet, may be secured with the assistance of rolled towels, blankets, tape, or a commercial head immobilizer. With the helmet in place, towels or blankets are often sufficient to fill any voids, creating a stable rigid construct on the spine board. Then the helmet may be directly secured to the spine board with adhesive cloth tape. The athlete's torso, pelvis, and legs should be secured with a minimum of two straps; three or four straps are preferable. When this process is completed the athlete should be securely immobilized for transport with protective gear intact, and in stable condition.
Although it is always preferable to avoid removing the helmet and shoulder pads, there are some indications that may require doing so. Studies in football [16•] and ice hockey  have clearly shown that removing the helmet or shoulder pads alone may induce excess movement in the cervical spine [16•,17–19]. Therefore, whenever it is necessary to remove either the helmet or the shoulder pads, it necessary to remove both. Indications to remove both the helmet and the shoulder pads include 1) when the facemask cannot be removed to gain access to the airway in a reasonable time period; 2) when the design of the helmet is such that the airway cannot be controlled, or ventilation provided, after the facemask has been removed; 3) if the helmet and chin straps do not adequately immobilize the head, permitting motion within the helmet; 4) if the helmet prevents immobilization for transport in an appropriate position; 5) when multiple injuries require full access to the shoulder area; and 6) poorly fitting shoulder pads preclude the ability to properly immobilize the spine [16•,18]. In these instances, helmet removal and placement of a hard cervical collar or rolled towels under the head to prevent hyperextension should be performed by trained personnel following a specific protocol.
As per all other maneuvers, the team leader maintains the position of the head and neck, and directs the procedure. First the chin strap is detached or cut. Cutting the chin strap is usually preferred since it results in less jarring movements. Second, the cheek pads should be removed. This is can be accomplished by inserting a screw driver, tongue depressor, reflex hammer handle, or other flat bladed instrument in between the cheek pads and the helmet shell to pry the air inflated cheek pads away from their snap attachments. The new Riddell football helmet has cheek pads that are not removable and must be punctured with an 18-gauge needle. In addition, some helmets are equipped with air bladder padding systems. These air bladders can be deflated by inserting an air pump needle or 18-gauge spinal needle into the ports, which are usually located on the external surface of the helmet along the midline. Removing or deflating the cheek pads and other air bladders will make it much easier to remove the helmet without inadvertently moving the head. Third, before attempting to remove the helmet, preparations must be made to simultaneously remove the shoulder pads.
The Inter-Association Task Force [16•] recommends the following steps to remove the shoulder pads when required by the criteria listed above: 1) cut the jersey and all other shirts from the neck to the waist and from the midline to the end of each arm; 2) cut all straps used to secure the shoulder pads to the torso (note that cutting is always preferable to unbuckling or unsnapping to limit unnecessary motion); 3) cut all straps used to secure the shoulder pads to the arms; 4) cut the laces or straps over the sternum; and 5) cut and remove any and all accessories such as neck rolls or collars, so that they can be removed simultaneously with the shoulder pads. At this point the team is ready to begin removing the helmet and shoulder pads.
A second trained rescuer is required to remove the helmet and shoulder pads. While the team leader remains positioned cephalad to the athlete's head as in the previous procedures, the second rescuer should be positioned caudal to the athlete's head. Straddling the athlete's chest is not recommended because it will likely make it more difficult to lift the athlete when it comes time to remove the helmet and shoulder pads. The second examiner should place his or her forearms on the athlete's chest while holding the athlete's head with his or her hands and stabilizing the athlete's maxilla with the thumbs. At this point, the second rescuer should assume responsibility for maintaining cervical stabilization and directing the remainder of the procedure. At least two to four additional rescuers should be positioned on either side of the athlete, adjacent to the torso, hips, and legs. At the second rescuer's command, the athlete should be lifted and the team leader should remove the helmet and shoulder pads while the second rescuer maintains cervical stabilization. All shirts, jerseys, neck rolls, and extenders should be removed at this time. The posterior aspect of a hard cervical collar should be positioned properly and patient lowered back down at the second examiner's command.
While removing the helmet, the helmet should not be spread apart by the ear holes. Studies have demonstrated that this maneuver only serves to tighten the helmet on the forehead and head region [20,21]. Removing or deflating the cheek pads should preclude the need to spread the helmet apart. If the helmet does not move freely, slight traction may be applied while the helmet is gently maneuvered anteriorly and posteriorly. Note that the head and neck unit must not be allowed to move when the helmet is being manipulated. The shoulder pads should be easily removed by spreading apart the front panels and pulling them around the head.
Injuries to the thoracic and lumber spine are much less common. The upper thoracic spine (T1–T10) is stabilized by the ribs and the facet orientation, as well as the sternum, and is less susceptible to trauma. At the thoracolumbar junction, however, there is a fulcrum of increased motion, and this area is more commonly affected by spinal trauma. Many of the same principles used with traumatic cervical spine injuries can be applied to traumatic thoracolumbar spine injuries. If the athlete experiences thoracolumbar pain, neuromuscular symptoms, or loss of lower extremity motion, the spine must be stabilized and the athlete placed and transferred on a spine board for further evaluation.
Once the athlete has been stabilized and a spinal cord injury is suspected, expeditious transfer to a medical facility is required. Emergency medical services (EMS) should be contacted immediately following the examiner's initial assessment. Transportation is necessary for any athlete with mental status changes, neck pain or tenderness, limited active cervical spine motion, and symptoms referable to a cord injury. As stated above, the patient must be fully immobilized on a spine board with the helmet and shoulder pads remaining in place. The facemask should be removed prior to the transfer and the jaw-thrust technique is a safe, effective method of maintaining a well aligned, patent airway .
The initial diagnostic assessment of an athlete with a suspected spinal injury should include a routine radiographic examination. The anteroposterior and lateral images should be obtained with the head, neck, and trunk still immobilized. Additional orthogonal views, computed tomography, and MRI may provide more detailed information; however, horizontally oriented fractures and subtle subluxations are best identified on the routine radiographs. The choice of imaging techniques will depend on the athlete's physical and neurologic examination, physician preference, and availability of the imaging modalities. Subsequent treatment will be specific to the identified injury.
Catastrophic spine injury can be an overwhelming event in an athlete's life. Rapid on-field diagnosis and early stabilization can help to optimize the outcomes of these catastrophic events. A concerted effort from the athletic team's care providers is crucial for effective on-field management and emergency transportation. In the presence of a suspected cervical spine injury, well-fitted helmets and shoulders pads should not be removed in the prehospital management unless absolutely necessary. Injuries to the thoracic and lumbar regions are more commonly associated with repetitive flexion and extension. However, when acute traumatic thoracolumbar injuries occur, strict spinal precautions must be followed with the athlete's spine stabilized on a spine board and transferred to a medical facility for further evaluation. An improved knowledge and understanding of on-field diagnosis and management can lead to improved prevention and emergent treatment strategies.
Effective treatment of the spine injured athlete begins with having the appropriate tools (spine board, anvil pruner, screw driver, oral/nasal airway, reflex hammer, 18-gauge spinal needle, hard cervical collar, sharp knife, wire/bolt cutters) ready prior to an injury occurring. Appropriate members of the staff should be familiar with the type of equipment worn by the athletes and appropriate spinal stabilization techniques. Predetermined pathways for communication with EMS and transportation should be established. All personnel should be instructed never to move a injured athlete until the team leader evaluates the athlete. The evaluation should begin with ABCs, assessment of level of consciousness, and activation of EMS. On-field management should begin with stabilization of the cervical spine, and proceed to log rolling, and ultimately to stable immobilization of the cervical, thoracic, and lumbar spine on a spine board, with the head immobilized in the helmet, the shoulder pads on, and the facemask removed. At this point, further evaluation of the athlete's condition may be performed while the athlete is stable for transport to a dedicated facility.
References and Recommended Reading
Papers of particular interest, published recently, have been highlighted as: • Of importance, •• Of major importance
1. Funk FJ, Wells RE: Injuries of the cervical spine in football.Clin Orthop
2. Torg JS: Cervical spine injuries.Orthopaedic Knowledge Update: Sports Medicine,
edn 3. Edited by Garrick JG. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2004:3–18.
3. Torg JS, Vegso JJ, O'Neill MJ, et al.
: The epidemiologic, pathologic, biomechanical, and cinematographic analysis of football-induced cervical spine trauma.Am J Sports Med
4.• Banerjee R, Palumbo MA, Fadale PD: Catastrophic cervical spine injuries in the collision sport athlete, part 1: epidemiology, functional anatomy, and diagnosis.Am J Sports Med
This article reviews the current concepts on the epidemiology, functional anatomy, and diagnosis in collision sports-related cervical spine injuries. It provides a rational approach to the early recognition, and an algorithm for on-field evaluation, of the different clinical syndromes associated with a cervical spine injury.
5. National Spinal Cord Injury Statistical Center: Spinal Cord Information Network: Facts and Figures at a Glance. University of Alabama at Birmingham.http://www.ncddr.org/rpp/hf/hfdw/mscis/nscisc.html
Accessed Oct. 31, 2004.
6. McAlinden RJ: On field evaluation and management of head and neck injured athletes.Clin in Sports Med
7. Wojtys EM, Hovda D, Landry G, et al.
: Concussion in sports.Am J Sports Med
8. Waeckerle JF, Kleiner DM: Protective athletic equipment and cervical spine imaging [editorial].Ann Emerg Med
9.•• Waninger KN: Management of the helmeted athlete with suspected cervical spine injury.Am J Sports Med
This is a review article of published evidence on cervical management of the helmeted athlete with a suspected spinal injury. It provides an approach to the neck-injured helmeted athlete and algorithms for on-field and emergency department evaluations.
10.• LaPrade RF, Broxerman RJ, Bahr M, et al.
: Care and Transport of Injured Participants with Potential Spine Injuries from Ice Rinks. Safety in Ice Hockey,
vol 3. ASTM STP 1341. Edited by Ashare AB. West Conshohocken, PA: American Society for Testing and Materials; 2000.
This article reviews the safety issues for proper immobilization of spine-injured athletes and the transfer mechanisms recommended for removing them from the ice. During the transfer process, it is recommended that the helmet be left on all ice hockey athletes to provide stability to the cervical spine.
11. Hoenshel RW, Pearson DB, Kleiner DM: The technique most commonly employed with a FM extractor [abstract].J Athl Train
12. Kleiner DM, Sonnenberg RJ: The influence of temperature on the ability to cut the football helmet facemask loop-strap attachement [abstract].J Athl Train
13. Knight KL: Editorial: removing football helmet facemasks.J Athl Train
14. Kleiner DM: Football helmet facemask removal.Athletic Ther Today
15. Kleiner DM: Facemask removal vs. facemask retraction [abstract].J Athl Train
16.• Kleiner DM, Almquist JL, Bailes J, et al.
: Prehospital care of the spine injured athlete. A document from the Inter-Association Task Force for Appropriate Care of the Spine Injured Athlete.
Dallas: National Trainers' Association; 2001.
This article provides recommendations for prehospital care and safety precautions of the spine-injured athlete. It provides a complete set of guidelines and recommendations regarding helmet, facemask, and shoulder pad removal and offers an extensive look at the many aspects of caring for an athlete with a suspected spinal injury.
17. Swenson TM, Lauerman WC, Donaldson WF, et al.
: Cervical spine alignment in the immobilized football player: radiographic analysis before and after helmet removal.Am J Sports Med
18. LaPrade RF, Schnetzker KA, Broxterman RJ, et al.
: Cervical spine alignement in the immobilized ice hockey player: a computed tomographic analysis of the effect of helmet removal.Am J Sports Med
19. Kleiner DM, Pollack AN: Dos and don'ts of football helmet removal.JEMS
20. Feld F, Blanc R: Immobilizing the spine injured football player.J Emerg Med Serv
21. Kleiner DM, Bozeman WP, Caro D, et al.
: Knowledge of football equipment removal guidelines among attendees of a regional emergency medicine meeting [abstract].
Jacksonville Beach, FL: Southeastern Regional Meeting of the Society for Academic Emergency Medicine; April 12–14, 2002.