Abstract:
Trauma cervical stability devices for using by ambulatory personnel arriving at the scene of an injured patient are disclosed. The trauma cervical stability devices comprise a cap element, releasable and adjustable head straps, a shoulder harness, and at least one adjustable member operatively connected to the cap element and the shoulder harness. The trauma cervical stability devices are compact, easy to use, inexpensive to manufacture, and can be placed on a patient with little or no movement of the patient. The trauma cervical stability devices are also useful in diagnosing the severity of damage to a neck and the stability of the patient&#39;s neck by applying forces to the patient&#39;s head using the trauma cervical stability device.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    The invention is directed to trauma cervical stability devices and, in particular, to adjustable cervical stability devices capable of easy and cost effective use by ambulatory personnel at the scene of the injury and of allowing injury diagnosis upon arrival at the hospital. 
         [0003]    2. Description of Art 
         [0004]    Trauma cervical collars are generally known in the art. Briefly, these cervical collars are carried on ambulances and other emergency personnel vehicles and are usually one-time use devices. These cervical collars provide limited, if any, means to adjust the cervical collar to fit the patient while securing the cervical collar to the injured patient. Generally, the patient must be moved to secure the cervical collar to the patient. Movement of the patient, however, can cause additional injury to the patient. In those cervical collars where adjustment is provided, the adjustment capabilities are limited which can result in the patient&#39;s head not being sufficiently stabilized with respect to the patient&#39;s spine, neck, or body. 
         [0005]    In other cervical collars, adjustment of the cervical collar may be achieved without excessive movement of the patient, however, the cervical collar is large and complex. Thus, these cervical collars are not only difficult to store in emergency vehicles where space is limited, they are difficult to use by emergency personnel. Accordingly, these types of devices instead are used to rehabilitate the patient&#39;s injured neck, e.g., after diagnosis and, generally, operation on the patient at a hospital, as opposed to stability a traumatic injury to a patient at the scene of the injury. 
       SUMMARY OF INVENTION 
       [0006]    Trauma cervical stability devices for using by ambulatory personnel arriving at the scene of an injured patient are disclosed. Broadly, the trauma cervical stability devices comprise a cap element, releasable and adjustable head straps, a shoulder harness, and at least one adjustable member operatively connected to the cap element and the shoulder harness. The trauma cervical stability devices are compact, easy to use, inexpensive to manufacture, and can be placed on a patient with little or no movement of the patient. The trauma cervical stability devices are also useful in diagnosing the severity of damage to a neck and the stability of the patient&#39;s neck by applying forces to the patient&#39;s head using the trauma cervical stability device. It is to be understood, however, that the effects and results of the trauma cervical stability devices disclosed herein are dependent upon the skill and training of the operators and surgeons. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0007]      FIG. 1  is a perspective view of one embodiment of the trauma cervical stability device disclosed herein shown secured to a patient. 
           [0008]      FIG. 2  is a perspective view of the trauma cervical stability device shown in  FIG. 1  illustrated in the flat position before being secured to a patient. 
           [0009]      FIG. 3  is a front perspective view of another embodiment of the trauma cervical stability device disclosed herein shown secured to a patient. 
           [0010]      FIG. 4  is a side perspective view of the trauma cervical stability device illustrated in  FIG. 3  shown secured to a patient. 
           [0011]      FIG. 5  is a back perspective view of the trauma cervical stability device illustrated in  FIG. 3  shown secured to a patient. 
           [0012]      FIG. 6  is a close-up perspective view of a track for use with the trauma cervical stability device shown in  FIG. 3 . 
           [0013]      FIG. 7  is a cross-sectional view of the track shown in  FIG. 6 . 
           [0014]      FIG. 8  is a graph showing sagittal plane intervertebral translation at C 4 -C 5  in intact spines. 
           [0015]      FIG. 9  is a graph showing change in average disc space height (% C 4  endplate width) per 100N applied traction. 
           [0016]      FIG. 10  is a graph showing the change in average disc space height with applied traction (% C 4  endplate width). 
           [0017]      FIG. 11  is a graph showing applied traction to the head (N) required to distract disc space 1 mm. 
       
    
    
       [0018]    While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF INVENTION 
       [0019]    Referring now to  FIGS. 1-2 , in one embodiment, trauma cervical stability device  30  includes cap element  40 , shoulder harness  50 , head strap  64 , chin strap  70 , anterior adjustable members  80 ,  81  and posterior adjustable members  90 ,  91 . Cap element  40  comprises an inner wall surface  42  ( FIG. 2 ) shaped for receiving the head of a person or patient. Cap element  40  may be formed from any suitable material that provides rigidity, such as plastic materials. As shown in  FIG. 2 , inner wall surface  42  includes a cushion material  43 , such as foam, so that inner wall surface  42  can conform to the contour of the patient&#39;s head. 
         [0020]    Cap element  40  covers the posterior and crown or top portions of the head of the patient. In the embodiment shown in  FIGS. 1-2 , cap element  40  covers not only the posterior and crown portions of the head of the patient, but also extends over the forehead of the patient. Although cap element  40  is shown in the embodiment of  FIGS. 1-2  as being formed of a single piece of material, it is to be understood that cap element  40  may be formed by two or more separate pieces such as in the embodiment of  FIGS. 4-7 . 
         [0021]    Due to cap element  40  covering the posterior surface of the patient&#39;s head as well as a at least a portion of the frontal lobe of the patient&#39;s head, which, in some embodiments also includes covering a portion of the forehead of the patient, when cap element  40  is connected to shoulder harness  50  as discussed in greater detail below, a downward force is applied to the head of the patient to assist in stabilizing the head of the patient relative to the body of the patient. The term “downward force” is used herein to describe forces applied in the direction of from the top of the head to the body and includes forces applied straight down toward the body, e.g., at a vertical angle (i.e., at a right angle to the horizon), as well as at an angle other than a vertical angle, e.g., at a 45 degree angle, a 30 degree angle, a 10 degree angle, an 80 degree angle, to the vertical angle. 
         [0022]    Shoulder harness  50  includes front or breast plate  52  and back plate  54 . One or both of breast plate  52  and back plate  54  includes inner wall surfaces having a cushion for conforming to the shape of the patient&#39;s body to support and comfort the patient&#39;s body. In one embodiment, both breast plate  52  and back plate  54  are formed from a rigid material, such as plastic, having a foam insert secured to the inner wall surface of the breast plate  52  and back plate  54 . Shoulder straps  56  and body straps  58  releasably secure breast plate  52  with back plate  54 . In the embodiment shown in  FIGS. 1-2 , shoulder straps  56  and body straps  58  include Velcro® pads  57  to releasably secure breast plate  52  to back plate  54 . 
         [0023]    Head strap  64  and chin strap  70  include a soft, cushioned inner wall surfaces  66 ,  72 , respectively for conforming to and/or providing comfort to, the patient&#39;s head and chin. Head strap  64  and chin strap  70  are releasably secured to cap element  40 . In the embodiment shown in  FIGS. 1-2 , head strap  64  and chin strap  70  include Velcro® pads  67 ,  73  to releasably secure head strap  64  and chin strap  70  to cap element  40 . 
         [0024]    Anterior adjustable members  80 ,  81  are secured at their upper and lower ends to chin strap  70  and breast plate  52 , respectively. In one embodiment, anterior adjustable members  80 ,  81  are secured at their upper and lower ends to chin strap  70  and breast plate  52  respectively by rotatable members (not shown) to allow the connections between the upper and lower ends of anterior adjustable members  80 ,  81  to chin strap  70  and breast plate  52 , respectively, to pivot and rotate so that the angle of intersection between anterior adjustable members  80 ,  81  chin strap  70  and breast plate  52  can be adjusted. Suitable rotatable members include, but are not limited to, lockable ball and socket connections so that the connections can pivot to the desired orientation and locked in place. Alternatively, only one of the connections between anterior adjustable members  80 ,  81  and chin strap  70  or breast plate  52  is rotatable, so that the other connection is fixed, i.e., the angle of intersection between anterior adjustable members  80 ,  81  and chin strap  70  or breast plate  52  cannot be adjusted. 
         [0025]    Posterior adjustable members  90 ,  91  are secured at their upper and lower ends to cap element  40  and back plate  54 , respectively. In one embodiment, posterior adjustable members  90 ,  91  are secured at their upper and lower ends to cap element  40  and back plate  54  respectively by rotatable members (not shown) to allow the connections between the upper and lower ends of posterior adjustable members  90 ,  91  to cap element  40  and back plate  54 , respectively, to pivot and rotate so that the angle of intersection between posterior adjustable members  90 ,  91  and cap element  40  and back plate  54  can be adjusted. Suitable rotatable members include, but are not limited to, ball and socket connections. Alternatively, only one of the connections between posterior adjustable members  90 ,  91  and cap element  40  or back plate  54  is rotatable, so that the other connection is fixed, i.e., the angle of intersection between posterior adjustable members  90 ,  91  and cap element  40  or back plate  54  cannot be adjusted. 
         [0026]    Anterior adjustable members  80 ,  81  and posterior adjustable members  90 ,  91  may be any device known to persons skilled in the art that are capable of having their length adjusted. As shown in  FIGS. 1-2 , both anterior adjustable members  80 ,  81  and posterior adjustable members  90 ,  91  are formed by upper members  80 A,  90 A, and lower members  80 B,  90 B in sliding engagement with each other and held in contact with each other by bracket  82  having set screw  83 . Tightening set screw  83  secures upper members  80 A,  90 A, and lower members  80 B,  90 B within bracket  82  so that no additional lengthening of anterior adjustable members  80 ,  81  or posterior adjustable members  90 ,  91  is permitted. Loosening set screw  83  releases upper members  80 A,  90 A, and lower members  80 B,  90 B from within bracket  82  so that they can sliding axially along each other thereby permitting additional lengthening of anterior adjustable members  80 ,  81  and posterior adjustable members  90 ,  91 . 
         [0027]    One or more attachment members may be included as part of trauma cervical stability device  30  so that pulleys, weights, loads, or forces can be applied to trauma cervical stability device  30  in one or more directions. For example, cap element attachment member  46  may be included as part of cap element. As shown in  FIG. 1 , cap element attachment member  46  is located at the upper end of posterior adjustment member  90 . Additionally, breast plate attachment member  59  is located at the lower end of anterior adjustment member  80 . Attachment members  46 ,  59  are shown in  FIGS. 1-2  as hooks, however, it is to be understood that attachment members  46 ,  59  may be any other device capable of securing pulleys or other traction or loads to trauma cervical stability device  30 . Suitable attachment members  46 ,  59  include snaps and belt and buckle connections. 
         [0028]    Referring now to  FIGS. 3-7 , in another embodiment, trauma cervical stability device  130  includes cap element  140 , shoulder harness  150 , head straps  164 , and adjustable members  180  and  181 . Cap element  140  comprises two portions, posterior portion  141  and anterior portion  142 . As shown in  FIGS. 3-5 , anterior portion  142  is position above the patient&#39;s forehead. Posterior portion  141  is connected to anterior portion  142  by cap element straps  144 . Like the embodiment of  FIGS. 1-2 , an inner wall surface of one or both of posterior portion  141  and anterior portion  142  may be shaped for receiving the head of the patient and cap element  140  may be formed from any suitable material that provides rigidity, such as plastic materials. Additionally, a cushion material such as foam may be disposed on the inner wall surfaces of one or both of posterior portion  141  and anterior portion  142  so that inner wall surfaces of these portions of cap element  141  can conform to the contour of the patient&#39;s head. Medical gauze may also be placed between the patient&#39;s head and cap element  140  to help control bleeding from lacerations on the head. The pressure from cap element  140  can be used to help control bleeding from head lacerations. 
         [0029]    Cap element  140  covers the posterior and crown or top portions of the head of the patient. Due to cap element  140  covering the posterior surface of the patient&#39;s head as well as a at least a portion of the crown portion of the patient&#39;s head, which, in some embodiments also includes covering a portion of the forehead of the patient, when cap element  140  is connected to shoulder harness  150  as discussed in greater detail below, a downward force is applied to the head of the patient to assist in stabilizing the head of the patient relative to the body of the patient. The term “downward force” has the same meaning as described above with respect to the embodiment of  FIGS. 1-2 . 
         [0030]    Shoulder harness  150  includes front or breast plate  152  and, optionally, back plate  154 . One or both of breast plate  152  and back plate  154  includes an inner wall surface having a cushion for conforming to the shape of the patient&#39;s body to support and comfort the patient&#39;s body. In one embodiment, both breast plate  152  and back plate  154  are formed from a rigid material, such as plastic, having a foam insert secured to the inner wall surface of the breast plate  152  and back plate  154 . Back plate straps  156  and body straps  158  releasably and adjustably secure breast plate  152  with back plate  154  such as through the use of Velcro® pads, buckles, snaps, stitching, or other fastener members (not shown). Body straps  158  can be directly connected from the front of breast plate  152 , around the body, and back to breast plate  152 , such as to the portion of breast plate  152  that rests on the back of the patient&#39;s shoulders. Thus, back plate  154  is not required. Body straps  158  can be releasably and adjustably connected to front plate  152 , back plate  154  or front and back plates  152 ,  154  to facilitate securing trauma cervical stability device  130  to the patient. 
         [0031]    Cap element straps  144  and head straps  164  can include soft, cushioned inner wall surfaces for conforming to and/or providing comfort to, the patient&#39;s head. Both cap element straps  144  and head straps  164  may be releasably and adjustably connected to cap element  40  such as through the use of Velcro® pads, buckles, snaps, stitching, or other fastener members (not shown). Cap element straps  144  can be releasably and adjustably connected to one or both of posterior portion  141  and/or anterior portion  142  of cap element  141 . Head straps  164  can be releasably and adjustably connected to cap element  140  at both ends of head straps  164 . As shown in  FIGS. 3-5 , head straps  164  are releasably and adjustably connected to posterior portion  141  and anterior portion  142  of cap element  140  at both ends of head straps  164  by buckles  166 . 
         [0032]    Adjustable members  180 ,  181  are secured to cap element  140 . In the embodiment of  FIGS. 3-7 , adjustable members  180 ,  181  are secured to posterior portion  141  of cap element  140 . The connection between adjustable members  180 ,  181  and cap element  140  can comprise a rotatable member to provide a pivot point and an adjustable fastener such as a set screw or wing-nut. 
         [0033]    The lower ends of adjustable members  180 ,  181  are operatively disposed in tracks  190 ,  191 , respectively. Tracks  190 ,  191  permit movement of the lower ends of adjustable members  180 ,  181  in the direction of arrows  193  (i.e., toward the patient&#39;s head),  194  (i.e., away from the patient&#39;s head) ( FIG. 6 ). The lower ends of adjustable members  180 ,  181  may be operatively associated with tracks  190 ,  191  in any manner known to persons of ordinary skill in the art so as to provide movement in the direction of arrows  193 ,  194 . 
         [0034]    Referring now to  FIGS. 6-7 , in one particular embodiment, track  190 , which for purposes of this embodiment is identical to track  191 , comprises ratchet profile  195  disposed along inner wall surface  196  of tracks  190 . Ratchet profile  195  permits movement of the lower ends of adjustable members  180 ,  181  in one direction, i.e., in the direction of arrow  193  toward the head, so that the orientation of adjustable members  180 ,  181  can be modified as necessary to secure trauma cervical stability device  130  to the patient. To move the adjustment members  180 ,  181  away from the head, each adjustment member  180 ,  181  or each track  190 ,  191  may include a release member, discussed in greater detail below, that releases adjustment members  180 ,  181  from ratchet profile  195 , allowing movement of the lower ends of adjustment members  180 ,  181  within track  190 ,  191 , respectively. 
         [0035]    The upper side of track  191  comprises rails  197 ,  198  and slit  199 . Rails  197 ,  198  restrict the lower ends of adjustable members  180 ,  181  from being disconnected from tracks  190 ,  191 , respectively, while slit  199  permits the lower ends of adjustable members  180 ,  181  to be inserted into, and made operatively associated with, tracks  190 ,  191 , respectively. 
         [0036]    In this particular embodiment, the lower ends of adjustable members  180 ,  181  comprise a front end and a back end, each of which is outwardly biased. In other words, both front end and back ends are designed such that the front end exerts a force in the direction of arrow  183  ( FIGS. 4 and 7 ) and the back end exerts a force in the direction of arrow  184  ( FIGS. 4 and 7 ). Therefore, to move lower ends of adjustable members  180 ,  181  along tracks  190 ,  191  respectively, away from the head of the patient (i.e., in the direction of arrow  194 ), front and back ends are pinched together so as to disengage from ratchet profile  195 . Thus, in this embodiment, the compression of the lower ends of adjustable members  180 ,  181  is the release member mentioned above. The lower ends of adjustable members  180 ,  181  can then be moved along the length of tracks  190 ,  191 , respectively, in the direction away from the head to adjust the fit of trauma cervical stability device  130  to the patient. 
         [0037]    To initially connect adjustable members  180 ,  181  to tracks  190 ,  191 , adjustable members  180 ,  181  are disposed through slit  199  within tracks  190 ,  191 , respectively, by turning adjustable members  180 ,  181  approximately 90 degrees from the orientation shown in  FIGS. 3-5 . After the lower ends are within tracks  190 ,  191 , adjustable members  180 ,  181  are rotated 90 degrees so that the lower ends of adjustable members  180 ,  181  are disposed under rails  197 ,  199 . Due to the outward biases of the front and back ends of each adjustable members  180 ,  181 , the lower ends of adjustable members  180 ,  181  move outwardly and under rails  197 ,  199 . As a result, the lower ends are retained within tracks  190 ,  191 . 
         [0038]    In another specific embodiment, cap element  140  includes one or more metallic studs  200  ( FIG. 5 ). These studs are disposed substantially along the axis of the vertebra so as to provide an alignment point for imaging, e.g., X-ray, purposes. Further, attachment members (not shown) can be included as part of trauma cervical stability device  130  to provide the same functions as attachment members  46 ,  59  in the embodiment shown in  FIGS. 1-2 . 
         [0039]    The embodiment shown in  FIGS. 3-7  operates and provides the same functionality as the embodiment shown in  FIGS. 1-2 , with the exception of the specific methods of how trauma cervical stability device  130  is installed and adjusted on the patient. These differences are evident to persons skilled in the art based upon the discussed above with respect to the differing structures. 
         [0040]    Although all of the structures of the trauma cervical stability devices disclosed herein can be formed out of any desired or necessary material to provide the required rigidity, plastic materials and other similar materials do not interfere with X-rays and other non-invasive imaging devices so that the trauma cervical stability devices are not required to be removed prior to imaging the patient&#39;s injury. 
         [0041]    Trauma cervical stability devices  30 ,  130  may be used in any number of diagnostic techniques. In one such use, the trauma cervical stability device diagnoses the severity of damage to the neck of patient as well as diagnose whether the neck is stable prior to administering additional aid to the patient. In one embodiment, the trauma cervical stability device is secured to a patient&#39;s body and head by placing the back plate on the posterior side of the patient and the cap element on the posterior surface of the head of the patient. The breast plate is then placed on the anterior side of the patient and the one or more head straps are secured along the sides of the head of the patient and, if included, the chin strap is secured under the chin of the patient. The back plate is secured to the breast plate through the body straps and, if present, the shoulder straps. 
         [0042]    After securing the trauma cervical stability device to the patient, each of the adjustable members are manipulated, e.g., extended, retracted, rotated, tilted, etc., to conform the trauma cervical stability device to the patient&#39;s neck and body orientation at the scene of the injury. After manipulating the adjustable member(s), the patient&#39;s neck is stabilized relative to the patient&#39;s body. 
         [0043]    Although the patient&#39;s neck is “stabilized” relative to the body through the trauma cervical stability device, it is to be understood that the patient&#39;s neck may not be stable without the trauma cervical stability device. Additionally, the patient&#39;s neck may have sustained substantially damage that may not be evident due to the trauma cervical stability device being secured to the patient&#39;s head and body. Therefore, as discussed below, the trauma cervical stability device can be further manipulated by a physician at the hospital to determine whether the neck of the patient is stable and, if not stable, how severe the damage to the patient&#39;s neck might be. 
         [0044]    To facilitate application of controlled traction loads to the head using the trauma cervical stability devices disclosed herein, a simple load sensing mechanism can be integrated into the articulation between adjustable members  180 ,  181  and cap element  140 . This load-sensing articulation can provide instant feedback to a physician regarding the relative magnitude of traction that is being applied to the head by the stabilization device. 
         [0045]    In the embodiment in which the physician determines whether the patient&#39;s neck is stable, the physician places a force or a load onto the patient&#39;s head and/or body such as by securing known weights to the attachment members of the trauma cervical stability device. The force or load caused by the weights is directed in a known direction using a pulley system. For example, the physician may place a load of 20 pounds in the upward direction parallel to the spine, i.e., pulling up on the head of a patient away from the body. If the motion between vertebrae in the spine is more than the intervertebral motion that occurs for an uninjured patient, the physician knows that the patient&#39;s cervical spine is not stable and that further diagnostic and imaging techniques, such as an MRI, are needed. 
         [0046]    Using trauma cervical stability device  130 , the inventors have completed a series of studies using whole cadavers to determine how best to diagnose injuries to the cervical spine. The whole cadaver model is a very good representation of motion live humans, since intervertebral motion in the fresh, unembalmed cadavers was statistically equivalent to motion that the authors have documented in live, asymptomatic humans. The equivalence of motion in fresh cadavers versus live humans is illustrated in  FIG. 8 . In  FIG. 8 , the data for the asymptomatic volunteers identified is from Reitman C. A., Mauro K. M., Nguyen L. et al., Intervertebral motion between flexion and extension in asymptomatic individuals;  Spine  2004; 24:2832-43, which is hereby incorporated by reference in its entirety; the data designated “Brown, et al.” is from Brown T., Reitman C. A., Nguyen L., et al., Intervertebral motion after incremental damage to the posterior structures of the cervical spine;  Spine  2005; 30:E503-E508, which is hereby incorporated by reference in its entirety; the data designated “Subramanian et al.” is from Subramanian N., Reitman C. A., Nguyen L., et al., Radiographic assessment and quantitative motion analysis of the cervical spine after serial sectioning of the anterior ligamentous structures;  Spine  2007; 32:518-26, which is hereby incorporated by reference in its entirety; and the data designated “Hwang et al” is from Hwang H., Hipp J. A., Ben-Galim P., et al., Threshold cervical range-of-motion neccesary to detect abnormal intervertebral in cervical spine radiographs;  Spine  2007 (currently in Press), which is hereby incorporated by reference in its entirety. 
         [0047]    During one study, traction loads were applied to the heads of whole cadavers before and after creating injuries to the cervical spine. These experiments defined the loads that need to be applied to the head to diagnose an injury to the spine. These experiments also defined the level of loads that will not overly distract the spine yet will allow detection of damage to the spine. Results of these studies are shown in  FIG. 9  which illustrates the amount of distraction that occurs in the intact cervical spine with application of axial traction, for each intervertebral level in the cervical spine. 
         [0048]    Referring now to  FIG. 10 , additional results from the study using whole human cadavers are shown. As illustrated in  FIG. 10 , there is not a very large amount of separation between vertebrae in response to traction loads applied to the head until extensive damage is done to the spine. Statistical analysis of this data also show that a modest traction load (89 Newton=20 lbs) is actually more sensitive for diagnosing cervical injuries than a higher load (178 Newton=40 lbs). 
         [0049]    It was further determined from the whole cadaver studies that much less traction is needed to distract the upper cervical versus lower cervical vertebrae. This observation is illustrate in  FIG. 11 . Using these results of these studies, physicians using trauma cervical stability device  130  can apply a number of different loads to the spine and, depending on the movement of the vertebra, can diagnose the severity of neck injury. For example, a low load would first be used to identify potential upper cervical injuries, followed by a modest load to diagnose upper or middle cervical spine injuries, followed by a higher load that would uncover injuries at any level. 
         [0050]    In addition to the physician determining whether the neck of the patient is stable, the physician can also engage in additional diagnostic investigation as to the severity of the patient&#39;s injured and unstable neck. To do so, the physician applies known forces or loads onto the patient&#39;s head and/or body in the same manner as discussed above and then measures the distance or amount of movement between vertebrae in the spine in each direction of the force or load. Intervertebral motion is measured from x-rays or other imaging methods or devices taken before and after the load is applied. The physician then compares each of the measured intervertebral motions to motions that are indicative of certain injuries. For example, if the two vertebrae rotate away from each other when 20 pounds of force is exerted on the patient&#39;s head in the upward direction parallel to the spine, i.e., pulling up on the head of a patient away from the body, then the physician can be fairly confident that the patient&#39;s injury is extremely severe. If the two vertebrae rotate in a manner resembling motion during flexion of the head and neck, this type of rotation suggests injury to posterior structures of the spine, such as the interspinous ligaments, facets, and/or ligamentum flavum. If, during application of axial traction, the two vertebrae rotate in a manner resembling motion that occurs during extension, this type of rotation suggests damage to anterior structures, such as the anterior longitudinal ligament and/or the intervertebral disc. 
         [0051]    It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the head straps may be a single strap that extends from one side of the cap element, passes through a slot on the top of the cap element, and extends to the other side of the cap element where it is releasably and adjustably connected to the cap element. Moreover, the tracks may not include a ratchet profile, but instead include slots or holes into which the lower ends of the adjustable elements are inserted. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.