Helmet Removal/Eject Assement

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Trammell - EJECT PROJECT Page 1
Assessment of the Risk of Worsening an
Injury to the Cervical Spine and or Spinal
Cord during Helmet Removal
PURPOSE
The purpose of this document is to assess the risk of worsening and existing injury
to the cervical spine and or spinal cord in a racing driver (participant) during
removal of the helmet.
INTRODUCTION
The rate of occurrence of spinal injury in motor vehicle crashes and the incidence
of cervical fracture are reviewed from the literature. The rates of specific levels of
injury and the injury types are reviewed.
This information forms the basis of assessment of risk of those types of injury that
might occur in a motor vehicle accident (MVA) and the mechanisms through
which a force might be applied that could potentially worsen the injury. This data
provides insight into the types of injury that may be encountered in motorsports,
and the frequency with which they are expected.
Data regarding the incidence of cervical spinal fracture (CSF) and cervical spinal
cord injury (SCI) in motorsports is addressed. The types of injuries recorded in
motorsports help to define the risk of exacerbation of that injury during helmet
removal.
The forces applied to the head and neck during manual helmet removal have
been investigated and are reported.
A novel system (EJECT®) is introduced and the forces that it applies to the head
and neck during pneumatically assisted helmet removal are evaluated and
reported. The claimed benefit of the EJECT® system (Appendix 1) is that the
forces generated by this device during mechanically assisted helmet removal are

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less than those during manual removal and therefore less likely to exacerbate an
existing injury to the cervical spine and or spinal cord. This document reviews the
relevant literature, provides data and expert opinion in support of those claims.
INCIDENCE, PREVALENCE AND OCCURRENCE OF CERVICAL FRACTURES AND
SPINAL CORD INJURY IN MVA
There are more than 150,000 spinal fractures per year in the United States.
Injuries from Motor Vehicle Accidents (MVA) include spinal injury in 12.5% -
18.6%. MVA account for 39% - 60% of new spinal fractures from all causes
(Ref 1,2,3,4). Cervical spinal injury is relatively rare occurring in only 2% -
3% of patients with blunt trauma who undergo imaging studies (Ref 5).
Occurrence of Spinal Cord Injury (SCI) from all causes is 3.2 - 5.3 /
100,000 in the US and Canada. SCI is the result of spinal injury from MVA
in 33% - 56%. Fractures of the cervical spine account for 60% - 80% of
SCI from all causes of trauma. Cervical fractures sustained in a MVA are
responsible for 60% of reported cases of SCI (Ref 6,7,1,8,9).
OCCURRENCE BY LEVEL AND TYPE OF CERVICAL INJURIES SUSTAINED IN MVA
The American College of Surgeons reports that trauma that results in spinal
injury involves the cervical spine in 55%, thoracic spine in 15%,
thoracolumbar spine in 15% and the lumbosacral spine in 15%.
Injuries of the cervical spine are most prevalent at the C1 level followed by
C5 - 7 levels. The combination of injury to the upper cervical spine (occiput,
C1 C2) and the lower cervical spine (C3-T1) was thought to be unusual
(Ref 7) but is now recognized as occurring in 5 - 9 % (Ref 4). 42% of SCI
are the result of MVA and are associated with a second noncontiguous SCI
in 28% (Ref 6). Negative clinical and radiographic examinations do not
prove the absence of pathological lesions (Ref 10).
Subaxial (C3 -C7) cervical spinal fractures were classified according to a
mechanistic method by Allen and Ferguson (Ref 7) in 1982. This review
classified the fracture types into six major groups as defined by the

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application of the major injury vector (MIV) representing that percentage of
the total group.
1) Compressive Flexion (CF) -28%
2) Vertical Compression (VC) - 8.5%
3) Distractive Flexion (DF) - 37.0%
4) Compressive Extension (CE) - 24.2%
5) Distractive Extension (DE) - 5.5%
6) Lateral Flexion (LF) - 3.0%
In this study the mechanism of injury was confirmed in all of the cases included in
the review. They noted that low stress rates produced fractures along the isocline
stress line, while high stress rates resulted in comminuted fractures.
This landmark study is important to this project in that it defines the MIV to be in
compression in 54.5% and distraction in 42.5%. They further subdivided the
fracture type by degree of severity. This established that the risk of spinal cord
injury increased in each phylogeny as the severity of the injury increased.
This is verified in subsequent studies that have shown that the rate of SCI
increases with increasing rate of application and magnitude of force (Ref 11).
The most common levels of injury in the lower cervical spine were at the C4/5 and
C5/6, with involvement of C5 vertebra in 60.8% of cases (Ref 4).
Complete SCI's were most commonly seen with burst fractures - 48% (CF and VC)
and bilateral facet fracture dislocation (DF) (Ref 12). There were multiple levels of
involvement in 28% at adjacent or at noncontiguous levels. Cervical injuries
sustained by non constrained operators of ATV's resulted in cervical spinal injuries
in 35.7% of those injured, 50% of whom sustained axial compression injuries. The
norm for these in other series of constrained persons is 12% (Ref 13). This is of
importance as it can be considered representative of the cervical injuries that
would be expected in an unrestrained operator of a motorcycle, or go kart.
Levels of injury as the result of MVA are most frequent at the C1 level followed by
C5, 6 and C7 in that order (Ref 6, 8). 14.1% of those sustaining injury in a MVA
sustain a spinal injury at the C1-2 level with 17.4% at C3 - 7 levels (Ref 14).

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The C1 - C2 level was involved in 9.7% of those with a spinal injury while the C3 -
C7 levels were involved in 11.1%. The remaining 79% involved the remainder of
the spine.
The importance of location of injury within the cervical spine and the nature of
the MIV (compression vs. distraction) is important in determining the risk of
exacerbating a cervical spinal injury during helmet removal in that removal of a
helmet is associated with the application of distractive force.
A subset of injury production in MVA is rollover. This is the most hazardous type
of MVA and the cervical spine is the 3rd most common location of injury in these
crashes after the head and thorax. Cervical fractures are usually compressive in
nature and are due to the inertia of the torso compression of the head into the
roof / ground commonly referred to as the diving mechanism (Ref 11). The
importance of this is that in a closed cockpit vehicle sustaining a rollover, the
mechanism of cervical injury has a probability for compression and therefore is
not likely to be adversely affected by a distraction force.
UPPER CERVICAL SPINE
Injuries of the upper cervical spine include injury to the base of the skull
(basilar skull fracture or occipital atlanto dissociation), atlas (C1) and axis
(C2) and their ligamentous attachments. They are more common in
children (Ref 15). Traumatic occipital cervical dissociation is the most
common fatal cervical spine injury (Ref 16). They account for 5 % - 12% of
fatalities in MVA. Death from MVA where there is cervical injury is
attributed to OC dissociation in 39% (Ref 17). The increased risk of this
injury in children calls attention to the potential for it presence in youthful
participants in motorsports, especially karting.
In those surviving the initial traumatic insult the distribution of cervical
fractures by level are 0.6% OAD, 23% C1 and / or C2 and C3 - C7 in
73.7% (Ref 18).
OAD - can occur from multiple points of application of force to the head,
with the neck in various positions. The final common pathway is one of
tensile loading of the ligamentous structures. OAD was present in 35 - 39%
of those fatalities from MVA where there was a cervical injury.

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C1 (Jefferson fractures) account for 10% of all cervical spinal fractures and
they are associated with concomitant spinal injuries 50% of the time. This
fracture type is the result of compressive force (Ref 4).
C2 - account for 20% of acute cervical fractures. The most common C2
lesion is traumatic spondylolisthesis (Hangman's fracture), which accounts
for 15% of cervical fractures. 75% of these fractures are the result of MVA.
This fracture results from varying mechanism but is most commonly
associated with tension extension loading (Ref 4).
Fractures of the odontoid process of C2 represent 7%-9% of cervical
fractures (Ref 19, 20). This injury was studied and found to be due to MVA
in 70% of cases. Type 2 fracture was present in 66.7% and type 3 in
33.3%. Type 2 fractures result from shear in the anterior posterior plane
(Ref 4). This injury occurred in most cases at a ΔV of less than 56kph.
These injuries are thought to be best stabilized with traction (Ref 21,22,23).
A type 3 injury associated with gross ligamentous failure has been
reported. In this case the application of only 5 # (22.2N) of cervical traction
resulted in catastrophic neurological injury (Ref 19). This was in spite of the
recommendation that the amount of traction for stabilization of these
injuries is 12 - 15 lbs. The range of recommended weight varies for 4 - 15
lbs. Type 3 fractures result from application of combined anterior posterior
and lateral shear loading (Ref 4).
The importance in the context of helmet removal is that the C1 and C2
fractures are related to either compression extension (Ref 6) or to
compression, or shear in fractures of the odontoid. These fractures are not
likely to be worsened by distractive forces the result of helmet removal.
This is however with exception as noted above.
OAD injuries however are likely to be adversely affected by the application
of distractive forces.

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FORCES APPLIED TO THE HEAD AND NECK REQUIRED TO PRODUCE INJURY
Forces applied to the cervical spine that result in failure of the vertebral
centrum or the spinal motion unit have been shown to have a mean of
3567N in compression, 1823N in flexion compression and 1089N in
extension compression (Ref 37).
Failures of the cervical spinal motion segment occur at 3.9Nm in extension
and 3.1Nm in flexion. Mean stiffness of the intact cervical segment is
1310N/mm. With occipital compression there were no significant motion
couplings observed. It was concluded that there is a wide variation in the
mechanical properties of connective tissues of the cervical region (Ref
24,25).
Side impacts have been studied and found to result in multiplanar injuries
at higher loads. The injury threshold was 6.5 gs with uniplanar injuries to
C4/5 through C7T1 in flexion, axial rotation or lateral bending. After 8g's
three plane injury was observed at C4/5, and C6/7, whereas two plane
injury occurred at C3/4 in flexion and lateral bending and C5/6 and C6/7 in
axial rotation and lateral bending. The conclusion of this study was that the
risk of neck injury was highest in rear impacts with the head rotated to the
side, followed by side and frontal impacts (Ref 26). This is of importance in
considering the possible adverse effects of extrication of an injured person
and the potential for worsening a cervical injury.
Although it would seem intuitive that the risk of injury would be related to
the forces of the accident this has been established in several studies and
it is recognized that impact velocity is the most important factor in
determining the risk of cervical spinal fracture (Ref 11). This was confirmed
in a recent study that reported that 43% of spinal fractures occurred in
MVA's where the ΔV exceeded the respective means for FMVC's (47.4kph)
and LMVC's (35.3kph) (Ref 2). There is one study that refutes this finding
and concludes that ΔV is not a conclusive predictor of cervical spine injury
(Ref 27). These studies may in fact be compatible in that the above
referenced works report the risk of spinal fracture at all levels vs. the risk of
cervical spinal fracture with respect to ΔV. This may in fact be the case as

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the occurrence of cervical spinal fracture as a result of MVA has been
shown to be related to the position of the head and neck and the degree of
muscular contraction at the time of force application, as well as the
direction, magnitude and rate of application of the force.
SPINAL INJURIES IN MOTORSPORTS
Spinal fractures in drivers of open cockpit open wheel race cars were studied
during the interval 1996 - 2005 in five racing series. There were 44 levels of
fracture in 38 occurrences of fracture in 36 drivers. There were 3 injuries at the
OC level, and 12 C3 - C7. Therefore the cervical fractures represented 34.1% of
the spinal fractures, which is consistent with that present in MVA's. The cervical
fractures involved the OC region in 6.8% of all spinal fractures, and represent 20%
of the cervical fractures with the remaining 80% involving the subaxial cervical
spine. All 3 of the OC injuries were fatal (REF 28).
It is thought that since the HANS has been compulsory in most all forms of
professional racing that the occurrence of axial distractive injuries has been
greatly reduced if not eliminated. There are no distractive basilar skull fractures or
upper cervical distractive injuries recorded in the IRL database since the HANS
was made compulsory. (Ref 29).
CURRENT RECOMMENDATIONS FOR ON SCENE MANAGEMENT OF SUSPECTED
CERVICAL SPINAL INJURY AND THE POTENTIAL CONSEQUENCES.
Field management of suspected cervical spine injuries is by immobilization
with a semirigid cervical collar, head immobilization, backboard, tape and
straps before, and during transfer to a definitive-care facility. If intubation is
required the neck should be maintained in a neutral position (Ref 30).
The issue here is that spinal immobilization has never been studied in
controlled randomized trials (Ref 31). Traditional thinking is being
challenged by emerging data. This data suggests that manual in line
stabilization may increase subluxation of unstable segments especially at
the occipital atlanto complex (Ref 18). Further there are reports that manual
in line stabilization does not limit the movement that occurs during

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intubation (Ref 32,33). There are several anecdotal reports that in the
presence of occiptocervical instability traction and collar immobilization can
reproduce displacement and precipitate neurological injury.
There is evidence that application of a cervical extrication collar can lead to
catastrophic neurological complication in patients with unstable cervical
injuries. The upper cervical spine seems particularly vulnerable. In a recent
cadaveric study application of a cervical collar caused grossly abnormal
increased separation at the site of a severely injured C1-C2 level. This
study was qualitative and did not report the distractive force generated by
the collar that resulted in distraction of the unstable injury. The preparation
of the cadavers did not allow for action of the cervical musculature, thus
representing an unconscious patient (Ref 34). In a review of 6 cases of
occiptocervical dissociation Ben - Galim et al commented that the amount
of protection afforded by active muscle control was remarkably substantial
(Ref 24).
There are no studies that define the degree of distraction force needed to
produce further separation of an unstable upper cervical distraction injury.
There is a clinical report of a longitudinal atlantoaxial dislocaton with type III
odontoid fracture that resulted in quadriplegia after application of 5# of
skeletal traction (22.2N) (Ref 19).
TECHNIQUE OF HELMET REMOVAL IN A PARTICIPANT WITH POSSIBLE CERVICAL
SPINAL INJURY
The technique of helmet removal in motorsports and all other helmeted
sports involves applying traction to the helmet by one responder while the
other supports the head in a neutral posture while providing manual
stabilization to the anterolateral neck through the mandible. (Appendix 1)
This method has been shown to result in a distractive force being applied to
the head neck complex.
Recent testing done at the Mayo Clinic (Appendix 3) show that manual
removal of a full face racing helmet generates distractive loads on the neck
of 209 lbs (929N) on average. This is significantly more than that reported
to produce neurologic injury an unstable upper cervical spinal injury.

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RISK OF EXACERBATION OF INJURY WITH THE CURRENTLY RECOMMENDED
TECHNIQUE
Injury of the OC Complex and Upper Cervical Spine
Distractive injuries to the occipitocervical complex and the upper cervical
spine are known to be at risk of exacerbation as a result of distractive force.
Although injuries of the occipitocervical complex were present in only 0.6%
of those admitted to hospital with cervical fractures (Ref 18) OCD is the
cause of death in 39% of fatalities from MVA. OCD represented 20% of the
injuries reported in open wheel racing all of which were fatal.
This injury is present 5 -10% of unconscious patients who sustain a cervical
injury. The cervical musculature provides stability to these injuries and
represents a significant protective mechanism (Ref 17). This coupled with
the fact that 33% of cervical injuries are not suspected at the scene (Ref 8)
require that the first responder have a high index of suspicion for the
presents of cervical injury.
As stated the traditional recommendations for stabilization of cervical
injuries are coming into question as potentially exacerbating and underlying
unstable injury.
Application of distractive force to this injury is known to result in axial
displacement with resultant neurological injury (Ref 15,16,34). The
application of an extrication collar can result in catastrophic neurological
complications in patients with unstable cervical injuries especially
dissociative injuries of the occipitocervical spine. Data that defines the
amount of force required to worsen this unstable distractive injury are
anecdotal with one case reported to have deteriorated from neurologically
normal to pentaplegia with the application of 5 lbs (22.2N).
Occipital Cervical Complex injuries are the most common cervical injury
resulting in death in MVA as proven post mortem. There are reports of

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survival following this injury (Ref 17). Clinically pure tensile neck injuries
are thought to be confined to the craniocervical junction and the base of the
skull (Ref 4).
Fracture at the C1 and or C2 level individually or in combination account for
9.7% of all traumatic spinal fractures and 14.1% of those occurring from
MVA and 20% of all cervical fractures (Ref 21,22,14). Lesions of C1 and
C2 are most frequently associated with compression extension
mechanisms and would not be adversely affected by a distractive force.
Therefore in motorsports the injury that would be most probably adversely
affected by the application of a distractive force is an occipital atlanto
dissociation, which is most commonly fatal but has been reported to be
survivable (Ref 17). This injury was present in 20% of those racing drivers
sustaining cervical injury in the series reported (Ref 28) and was uniformly
fatal. There were two cases OAD with survival not reported in that series
(Ref 29).
Unstable fractures of C1/2 have been reported where application of as little
as 5# of traction resulted in catastrophic neurological injury. Currently
recommended techniques for helmet removal (Appendix 2) have been
shown to generate distractive forces in excess of those required to
exacerbate an unstable injury. (Appendix 3)
Injury C3 - C7
Injuries of the lower cervical spine occur in 80% of racing drivers who
sustained cervical spinal injury. The injury that would be most at risk to
compressive loading that might occur during helmet removal would be a
cervical burst fracture most commonly involving the C5 vertebra. Cervical
burst fractures are present in 48% of those with SCI (Ref 12). Studies have
shown that spinal fractures are related to higher ΔV,s usually in excess of
those permissible un FMVSS208 (48kph). Spinal injuries were more
prevalent in frontal and lateral impacts when the ΔV was greater that 35.3
kph lateral or 47.4 kph frontal (Ref 2). Racing crashes frequently have ΔV
greater than this (Ref 35).

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The C5 level is the level of stress concentration in a compressive loading
scenario (Ref 36). Although there is no data with regard to the compressive
force required to exacerbate a cervical compression fracture the mean
compressive stiffness of the intact cervical segment has been reported to
be 1310N/mm. Compressive loads to failure of the cervical vertebra have
been reported to be mean of 3567N in compression, 1823N in flexion
compression and 1089 N in extension (Ref 37). Critical head velocity of
approximately 3.1m/s with the torso following is sufficient to produce neck
injury (diving model) (Ref 4). Further compressive force required to produce
additional neurological injury would be expected to be less but is not
known.
From data presented above developed as a result of a study at the Mayo
Clinic traction forces applied to the head and neck exceed those which
have been implicated in worsening cervical injuries. (35.8 - 57.7 lbs)
(Appendix 3)
There are no data with regard to compressive forces needed to precipitate
or worsen an existing spinal cord injury.
Injuries of the cervical spine that result from high energy vehicular
accidents are often unstable in multiple planes and are especially sensitive
to translation and rotation (Ref 36,24,25) and involve multiple levels that
may have multiple and or noncontiguous levels in 28% (Ref 12).
In view of the above there is essentially no method of manual removal of a
helmet, or of application of an extrication collar that will not exacerbate
some cervical injury and potentially result in neurological injury or
worsening of.
FORCES APPLIED TO THE NECK DURING EJECT DEPLOYMENT
The EJECT® device from Shock Doctor is a device that is reported to
provide a method of helmet removal that lessens the distractive and
compressive forces and moments on the neck (Appendix 3). This device
when deployed with the 16g CO2 cartridge resulted in a range of neck
loading from +0.7 lbs traction to -2.0 lbs of compression. This was for two

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sizes of two different motorsports helmet types each tested 6 times. This is
less than half of the traction force reported to have resulted in distraction of
an unstable upper cervical lesion (5#). There is no data of which we are
aware that defines the maximum acceptable compression loading that a
cervical spinal unit injured in compression can further withstand without
exacerbation of the injury. However based on the compressive loads to
failure quoted above, it is very unlikely that an additional 2.0 lbs of
compression would exacerbate any but the most severe and unstable of
injuries.
The worst-case scenario would be present in an individual with an unstable
compression injury in whom the EJECT® device was activated with the
helmet chinstrap still in place. If the helmet was constrained in that the
helmet was prevented from separating from the head then the energy in the
bladder could result in compressive load to the neck. In this scenario the
compression load applied to the neck was recorded to be a maximum of
9.4 lbs. This has the potential to worsen a grossly unstable compression
injury of the cervical spine.
In the case of attempted removal of a helmet with the chin strap tightly in
place, manual technique results in an average of 70.7 lbs of traction force
applied to the neck, while the EJECT® system deployed with the 16gCO2
cartridge generates only 1.0 lbs. Attempted manual removal results in a
flexion moment (-Mx) of 31.7 whereas deployment of the Eject system with
the 16gCO2 cartridge generates (+Mx) of 4.1 in lbs of extension, From the
preceding discussion unstable injuries to the upper cervical spine are most
commonly distractive in nature, while those of the lower cervical spine are
compressive. The forces generated by the EJECT® system are minimally
compressive and generate an extension moment. Care of the most
common injury in the lower cervical spine (C5 burst fracture) would
recommend immobilization with slight traction and neutral or slight
extension, both of which are accomplished in this worst case scenario with
helmet strap in place.
The other conceivable worst case scenario would be where there was
helmet damage associated with a depressed skull fracture. In this case

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inflation of the bladder could result in further depression of the fracture
without ejecting the helmet. In a case that resulted in injury of this
magnitude helmet damage would be evident and would suggest that
removal be done manually although this technique would expose the
injured to distractive loading on the neck and potential neurological injury
as pointed out. Even in this case if the skull were fractured and the helmet
intact the head load generated by deployment of the EJECT® system with
the 16gCO2 capsule would be 383.0 lbs of compression. This is
undesirable in that it would further depress a depressed skull fracture. This
data was generated from a bench model with and intact helmet and a rigid
skull. If there were sufficient damage to the helmet to allow a depressed
skull fracture to occur then it would follow that the helmet would not be
structurally intact and these compressive loads would not be generated on
the skull but would be mitigated by outward deformation of the helmet.
Tests have been conducted to show that placement of the EJECT system
into the helmet does not alter the helmet impact test specifications ( FIA
8860 - 2004). (Appendix 3-1)
CONCLUSIONS
Cervical spinal injuries are most frequently the result of motor vehicular
accidents. Spinal fractures account for 18.7% of injuries in open cockpit
open wheel racing car drivers. Cervical spinal fractures accounted for
42.9% of those.
Injuries to the basiocciput and upper cervical spine occurred in 20% of
those drivers who sustained cervical injury and were fatal in most cases.
Since the use of a head and neck restraint (HANS) was made mandatory in
these series, as well as others the incidence of injuries to the basiocciput
have been greatly reduced if not eliminated. Therefore the likelihood of
encountering such an injury in a racing driver wearing a HANR is minimal. I
In the presence of an unstable distractive injury to the basiocciput there is a
high probability that the application of traction to the head could result in
worsening of the injury and or neurological status. Manual helmet removal

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has been shown to generate an average of 26.9# of traction on the head
and 42.3# on the neck. The average moment in flexion (-Mx) was -13.2 in
lbs. Anecdotal data has shown that 5# of traction can result in catastrophic
neurological deterioration of such and injury.
The EJECT® system deployed with the 16g CO2 cartridge produces no
traction on the head on average, but rather applies compression loading to
the head of -21.5 #. There is no data available to show if this amount of
head compression could worsen a compressive injury of the upper cervical
spine. Although it is possible that it might, based on the forces needed to
produce such an injury, this small compressive load would be unlikely to do
so the opinion of our expert.
Compressive fractures of the cervical spine are clustered at the C5
vertebral body. Manual removal of the helmet results in average traction
forces on the neck of 42.3# with a flexion moment (-Mx) of 13.2 in lbs. The
most severe burst fractures result from a compressive flexion MIV thus it is
expected that applying a flexion moment to an injury where the MIV
included a flexion moment would be undesirable. Utilizing the Eject system
the traction force on the neck is 1.0 lbs on average and is accompanied by
an extension moment of +14.8 in lbs.
The EJECT® system for pneumatically assisted helmet removal results in
lower distractive forces on the head and neck than those produced by
manual removal and generate extension moments compared to flexion
moments for manual removal.
The only scenario in which the EJECT® system generated loads that might
exacerbate an existing injury would be in the case of a depressed skull
fracture where the helmet remained intact. This is a circumstance of
extremely low probability to the point of impossibility.
A subset of the data is that scenario in which the helmet strap is not
securely fastened and tightened (loose strap condition). In this situation
attempted manual removal of the helmet results in an average traction
force of 76.6 lbs and forward flexion moment (-Mx) of 10 in lbs. while use

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of the Eject system deployed using the 16gCO2 produced -1.8 lbs of
compression and an extension moment of 2.6 in lbs.
In this subset of data attempted removal of the helmet with the chin strap in
place and tight or securely fastened but not tight, resulted in high head
compressive loads on average of 383 lbs. This load is not transmitted from
the head through to the neck load cell so that a comparable compressive
load on the neck is not recorded. The clinical meaning of this is in
determinant.
There is also video evidence that use of the EJECT® system with the chin
strap removed results in a more fluid removal sequence with less
lengthening of the neck, and substantially less neck motion in flexion and
extension and anterior posterior displacement. This is consistently
accomplished. (REF 38)
Use of the EJECT® system for pneumatically assisted helmet removal
results in significantly less likelihood of injurious forces being applied to an
already injured cervical spine than does manual helmet removal even in the
most expert of hands. It would also result in uniformity and consistency in
the safe removal of helmets by first responders with a minimum of training.

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