This is a continuation in part application of Ser. No. 09/680,555 filed Oct. 5, 2000 now abandoned. 


   TECHNICAL FIELD 
   This invention pertains to the restoration of form and function of the skull on the cervical spine (neck) and, more precisely, relates to adjustment of the backward (extension) as well as the forward and/or lateral (flexion) motions of the skull on the cervical spine (neck). 
   BACKGROUND OF THE INVENTION 
   Injuries to the neck, especially flexion and extension (whiplash) injuries, cause joint, ligament, and muscle disfunctions that can limit motions of one or more of the spinal joints. Referring initially to  FIGS. 1-4 , shown in  FIG. 1  is the balanced position of the head  20  with the skull  22  on the lateral upright cervical vertebral column  24 . The head  20  is in equilibrium when the eyes  26  look horizontally, as shown by axis A. With the head  20  in this position, the plane of the bite, shown as axis B, is also horizontal, or parallel to axis A. Force is produced by the weight of the head  20  through its center of gravity lying at the front of the sella turcicia, which is shown as the intersection C of the gravity force line D and the horizontal axis A. The gravity force line D extends from the intersection C with the horizontal axis A through the anterior one-third of the C4-C5 disk. 
   The angle of the normal cervical spine lateral curve is measured between axis lines E of the posterior border of the C2 vertebra and the axis line F off the posterior border of the C7 vertebra. Normally, the intersection of the axis lines E and F should form an acute angle in the range of about 43° to 45°. 
   Referring to  FIG. 2 , the skull  22  and the cervical vertebral column  24  normally each have 7.5 degrees of forward flexion and 7.5 degrees of backward extension movement relative to the vertebrae below, producing 130 degrees of total flexion of the skull and neck. 
   Referring to  FIGS. 3 and 4 ,  FIG. 3  shows a representation of an x-ray of an injured skull  26  and cervical spine  28 . The center of gravity line D is reproduced to show the displacement of the cervical spine  28  from its normal position. In this case, the cervical spine  28  is displaced from its normal position relative to the center of gravity line D by approximately 1-¼ inch as shown in  FIG. 3 . There is a need for a device that can help restore the cervical spine  48  to a normal or substantially normal position as shown in  FIG. 4 . 
   SUMMARY OF THE INVENTION 
   The disclosed embodiments of the invention are directed to a spinal adjusting device that includes a base plate assembly and an upper plate assembly, the upper plate assembly connectable to the base plate assembly such that the upper plate assembly will drop to the base plate assembly when subjected to a predetermined amount of force. 
   In accordance with another embodiment of the invention, the base plate assembly includes a base plate and a coupling mechanism that couples the upper plate assembly to the base plate, the coupling mechanism including a drop assembly. 
   According to an additional embodiment of the invention, a reset lever is provided, affixed to the base plate of the device and configured to move the upper plate assembly into the cocked, or reset, position when a downward force is applied to a handle of the lever. 
   In accordance with a method of the present invention, the spinal adjusting device is placed under the patient&#39;s neck supporting the vertebra just below the vertebra and/or skull in need of repositioning. The coupling mechanism holds the upper assembly above the base plate until the patient&#39;s cervical spine and skull are flexed or extended, as required, with sufficient force to cause the upper assembly to drop to the base plate. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional illustration of the skull on the lateral upright cervical vertebral column. 
       FIG. 2  is an illustration of normal forward flexion and backward extension movement of the skull and cervical vertebrae. 
       FIG. 3  is from an x-ray of an injured skull and cervical spine before treatment in accordance with the invention. 
       FIG. 4  is from an x-ray of the same skull and cervical spine as in  FIG. 3 , after treatment in accordance with the invention. 
       FIG. 5  is a top plan view of a base plate assembly of a device in accordance with an embodiment of the invention. 
       FIG. 6  is a front elevation view of the assembled device of  FIG. 5 , showing the device in “cocked” position. 
       FIG. 7  is an isometric view of an upper plate assembly of the device of  FIG. 5 . 
       FIG. 8  is a front elevation view of the device of  FIG. 6 , in “uncocked” position. 
       FIG. 9A  is an illustration of a cervical vertebral column properly positioned for treatment in accordance with an embodiment of the invention. 
       FIG. 9B  is a detail of the embodiment of  FIG. 9A . 
       FIG. 10A  is an illustration of a cervical vertebral column properly positioned for treatment in accordance with another embodiment of the invention. 
       FIG. 10B  is a detail of the embodiment of  FIG. 10A . 
       FIG. 11  is an isometric view of an alternative embodiment of the invention illustrating a reset lever. 
       FIG. 12  is an isometric view of a spinal adjusting device configured for treating the vertebral column in accordance with another embodiment of the invention. 
       FIG. 13  is an isometric view of an embodiment of the invention illustrating a reset lever according to another embodiment of the invention. 
   


   DETAILED DESCRIPTION OF THE INVENTION 
   Referring initially to  FIGS. 5-7B , shown therein is a spinal adjusting device  100 , including a base plate assembly  102  (shown in  FIG. 5 ) for use with a patient  103 . In  FIG. 5  is shown the components of the base plate assembly  102 . The base plate assembly  102  includes a base plate  104 , ideally made of ⅛th inch steel plate. In one embodiment the base plate  104  has dimensions of 10 inches wide and 12 inches long. 
   One half  105   a  of a pin hinge  105  is welded in the center of the base plate  104  for attachment of an upper plate assembly  106  with a pin  108 . A tension adjustable drop assembly  110  is welded or otherwise affixed to the center of the forward end  104   a  of the base plate  104 . In one embodiment, the drop assembly  110  is ideally made of a 1½×1½×⅛ inch thick angle plate  111 . There is a ½ inch wide slot  112  milled in the center of the upright angle plate  111 . There is a ¼ inch hole  114  drilled ½ inch to the right of the slot  112  and ½ inch from the top of the angle plate  111 . 
   There is a 1½ inch long coupling nut  116  welded onto the upright angle plate  111 . The edge  113  of the nut  116  is even with the right edge  115  of the milled slot  112 . The top  119  of the coupling nut  116  is level with the top  121  of the angle plate  111 . A ¼th inch bolt  123  inserts in the hole  114  and attaches a ¾ inch diameter by ½ inch wide roller bearing  120  thereto with a nut  118 . A ½ inch diameter thumbscrew  122  3½ inches long is on the right side of the upright angle plate  111 . When the thumbscrew is screwed into the coupling nut  116  attached to the plate  111 , it compresses a 1 inch long tool spring  126  (shown in the cutaway in  FIG. 6 ) against a ½ inch ball bearing  128 . The ball bearing  128  is compressed against roller bearing  120  by the spring  126  and the thumbscrew  122 . The amount of tension between the ball bearing  128  and the roller bearing  120  may be adjusted by turning the thumbscrew  122  in or out of the coupling nut  116 . 
   Shown in  FIG. 7  is an upper plate assembly  106 . In one embodiment, the assembly  106  includes an upper plate  107  that is 6 inches wide and 8-½ inches long. One half  105   b  of the pin hinge  105  is welded on the under side  124  of the upper plate  107 . This one half hinge  105   b  fits into the other one half hinge  105   a  and attaches the upper plate  107  to the base plate  104  when the pin  108  is inserted into pin hinge halves  105   a  and  105   b . A 1½×1½×⅛th inch thick angle bar  132  1 inch long is welded to the center of the front end  107   a  of the under side of the upper plate  107 . The angle bar  132  includes a protruding leg  131  that rests on the laterally compressed bearings  120  and  128  when the invention is in the cocked position (See  FIG. 6 ). 
   To activate the device, sufficient force is applied to the patient&#39;s head and neck to cause the compressed bearings  120  and  128  to separate so that the angle bar  132  falls to the bottom  146  of the slot  112  and the entire upper plate  107  drops to the uncocked position, as shown in  FIG. 8 . The degree of force required to cause the compressed bearings  120  and  128  to separate as described may be referred to as the threshold force. 
   In the illustrated embodiment, the protruding leg  131  has an angled bottom face  152 . In another embodiment, the end face of the protruding leg  131  may have a flat surface to reduce the damage to the bottom plate. In the embodiment illustrated in  FIGS. 5-7  the upper plate drops approximately 1½ inches. A bent metal bar  134 , having upright legs  135  resembling a goal post, is affixed to the forward edge  107   a  of the upper surface of the upper plate  107 . In one embodiment, the metal bar  134  is ⅛th inch thick and 1½ inches wide. The two ends  133  of the bar  134  are bent upward at about a 62 degree angle to form 5 inch high legs  135  that are 11½ inches apart at the top and 8-12 inches apart at the bottom (see  FIG. 8 ). Two ⅛th inch×1 inch horizontal slots  136  and  138  are milled ⅛th inch from the end  133  in each upright leg  135 . The slots  136  and  138  are used for the attachment of a 3/32nd×⅞th inch nylon strap  140 , which is, in this embodiment, 16 inches long, between the two upright legs  135 . Two additional ⅛th×1 inch long horizontal slots  142 ,  143  (see  FIG. 7 ) are milled below either slot  136  or slot  138  on one of the upright legs  135  for securing the nylon strap  140  to the upright legs  135 . 
   The nylon strap  140  supports the back or sides of the patient&#39;s neck and may be precisely positioned under the lower vertebra of the two vertebrae in need of correction (see FIGS.  9  and  10 ).In use, the device  100  is preferably placed on a patient table  142 . It may be secured to the table  142  with fasteners or releasable connectors (not shown) or it may rest upon the table  142 . To use the device  100 , the patient  103  is placed supine on the firm table  142 . The device  100  is placed under the patient&#39;s neck  146  (see  FIGS. 9 and 10 ). The nylon strap  140  is positioned under the vertebra just below the vertebra in need of repositioning for extension, as shown in  FIGS. 9A and 9B , or under the vertebra just above the vertebra in need of repositioning for flexion, as in  FIGS. 10A and 10B   11 .  FIG. 9A  shows the general arrangement of a patient on the device in a position for extension.  FIG. 9B  is a detailed view of the skull and cervical vertebrae showing a misalignment between vertebrae C3 and C4. The strap  140  is shown positioned under C4.  FIGS. 10A and 10B  illustrate a similar configuration, in which the patient is positioned for flexion, with the misalignment between C4 and C5. The strap  140  is again positioned under C4. 
   The upper assembly  106  is made ready for use by lifting and rotating the upper plate  107  upward about the hinge pin  108  that connects the upper plate  107  and the base plate  104 . In this position, the angle bar  132  of the upper plate  107  is resting on the intersection of the compressed bearings  120  and  128  of the adjustable drop assembly  110  on the base plate  104  (see  FIGS. 12 and 13 ). 
   A skilled practitioner then flexes or extends and/or rotates the patient&#39;s entire cervical spine and skull on the nylon strap  140 , depending on the action (flexion or extension and/or rotation) that is needed to reposition the involved vertebrae relative to each other and/or the skull relative to the top vertebra. 
   After the spine  28  has been properly positioned and stressed (see  FIGS. 9 and 10 ), the skilled practitioner then applies an additional amount of force, i.e., the threshold force, on the patient&#39;s skull or body in the direction to be stressed, that is, flexed or extended. This additional force must be sufficient to cause the angle bar  132  protruding from the upper plate  107  to overcome the resistance of the compressed bearings  120  and  128 , so that the entire upper assembly  106  and the patient&#39;s head and neck drop until the protruding leg  131  on the angle bar  132  strikes the bottom  146  of the slot  112 . 
   The movement of the angle bar  132 , the upper assembly  106  and the vertebra resting on the nylon strap  140  are abruptly stopped when the leg  131  hits the bottom  146  of the slot  112 . When the angle bar  132  hits the bottom  146  of the slot  112 , the skull and/or vertebrae adjacent to the stopped vertebra continue moving. The misaligned joint between the vertebra that is stopped and the vertebra that continues moving are realigned as the vertebra is partially or completely sheared back into its proper position by this function (see  FIGS. 3 and 4 ). The device  100  resists the elongate force on the neck because the superior (head up) force is resisted in the opposite direction. Each cervical vertebra, including the condyles of the skull, in need of repositioning may be treated by this method using the device  100  of the invention. It may be necessary for the practitioner to support the patient&#39;s head or neck on the side of the strap opposite the side of the misalignment under treatment, to prevent undesired action on normal joints. For example, for flexion, as shown in  FIG. 10B , the point of intended treatment is between the C4 vertebra and the C5 vertebra, with the C5 vertebra to be sheared downward into alignment with C4. However, because of the weight of the head, there is some danger of the vertebra above the strap (C3) being sheared downward, as well. To prevent this, the practitioner may support the patient&#39;s head with one hand as he applies the additional force to the patient&#39;s body to activate the device. 
   Although it is possible for a patient to use this device alone, the patient would need proper training in the use of the device  100  before self-treatment could be recommended. 
   According to another aspect of the invention, the spinal adjustment device includes a reset lever configured to convert downward pressure on a handle of the lever into upward pressure against the lower surface of the upper plate in order to reset the device. 
     FIGS. 11 and 12  illustrate one example of such a reset lever. In this embodiment, the spinal adjustment device  100  includes a reset lever assembly  164  mounted thereon. The reset lever assembly  164  includes a mounting bracket  166  formed from a short length of 1″×1½″ channel metal. The mounting bracket  166  is affixed to the base plate  104  at the right edge, as shown in  FIG. 11 . A bolt  168  passes through holes in the mounting bracket  166  and through holes in a reset lever  170 , attaching the lever  170  to the bracket  166 . Ideally, the lever  170  is formed from a length of rod or tubing, preferably ¾ inches in diameter and 8-14 inches long, which extends 3 to 4 inches inward from the bracket  166  to a point between the base plate  104  and the upper plate  107 , and outward from the bracket  166  for a distance of 8-10 inches. The bolt acts as a pivot for the lever  170 . The inner end  170   a  of the lever  170  further includes a reset bearing  172 . The reset bearing  172  is preferably a roller bearing having a diameter of 1 inch and a thickness of ½ inch, and it is mounted on an upper portion of the inner end  170   a  of the lever  170  with a central axis parallel to the longitudinal axis of the reset lever  170  as illustrated in the cutaway view of  FIG. 11 . The outer end  170   b  of the reset lever  170  may include a handle or cover  174  to protect an operator&#39;s hand. 
   In operation, the lever  170  pivots on the bolt  168  on an axis parallel to the plane of the base plate  154  and perpendicular to a longitudinal axis of the lever  170 . Up and down movement of the inner end  170   a  of the lever  170  is constrained by the upper surface of the base plate  154  in a first direction and by the lower surface of the upper plate  107  in the opposite direction. When the inner end  170   a  of the lever  170  is raised, the reset bearing  172  presses against the lower surface  124  of the upper plate  107 . 
   The device  100  is reset or cocked by grasping the outer end  170   b  of the reset lever  170  and pressing it downward. The reset lever  170  pivots on the bolt  168 , causing the inner end  170   a  of the lever  170  to press upward against the lower surface  124  of the upper plate  107 . The force required to move the upper plate  107  into the cocked position is significantly less than that required to activate the device, inasmuch as, when in the uncocked position, the bearings  120  and  128  are separated by the leg  131  of the angle bar  132  and do not significantly resist upward movement of the leg  131 . Because of the leverage provided by the position of the pivot point  168  on the lever  170 , it is possible for the practitioner to reset the device  104  without removing the weight of the patient&#39;s head from the upper plate  107 . 
     FIG. 13  shows another embodiment of the reset lever, in which the reset lever  180  is formed from a single length of round bar. The bar may be mild steel having a diameter of about ⅜″. The bar is bent to form a handle region  182 , an arm region  184 , a pivot region  186 , a lifting region  188 , and a reset foot  190 . A pivot bracket  192  is welded or otherwise affixed to the upright angle plate  111  immediately beneath the coupling nut  116 . The pivot region  186  of the lever  180  passes through the pivot bracket  192 , which forms a fulcrum upon which the lever  180  rotates. From an outboard end  192   a  of the pivot bracket  192  the arm region  184  of the lever  180  curves in a direction away from the upper plate assembly  106  and terminates in the handle region  182 . From an inboard end  192   b  of the pivot bracket  192  the lift region  188  of the lever  180  curves in a direction toward the upper plate assembly  106  and terminates in the reset foot  190 , which is positioned between the upper and base plate assemblies  106 ,  102  in the approximate center of the upper plate  107 . The handle and arm regions  180 ,  182  may be covered with a protective material to protect an operator&#39;s hands during operation, and the reset foot  190  may be covered with a material selected to reduce friction and wear at the point where the foot  190  contacts the lower surface of the upper plate  107 . 
   In operation, the device is reset from an uncocked to a cocked position by exerting downward force on the handle region  182  of the lever  180 . The lever pivots on the pivot bracket  192 , causing the arm region  188  and the reset foot  190  to rise. The reset foot  190  exerts an upward force on the lower surface of the upper plate  107 , causing the upper plate assembly  106  to rise to the cocked position. It will be understood that the ratio of upward force exerted by the reset foot  190  versus the downward force exerted on the handle region will be approximately proportionate to the length of the handle and arm regions  182 ,  184  versus the length of the lift region and reset foot  188 ,  190 . Thus, a desired force multiplication ratio may be selected by selecting the respective lengths accordingly. 
   It is to be understood that while a preferred embodiment of the invention has been illustrated and described, various changes may be made therein without departing from the spirit and scope of the invention. 
   For example, the device components may be manufactured from steel, aluminum, or high-strength plastic, as appropriate. Common manufacturing methods may dictate changes in construction and assembly, such as replacing welds with bolts or rivets or vice-versa, etc. The dimensions may be varied according to specific applications, for example a device intended for use on children or small adults may be smaller, while a device intended for use on the lower spine may have variations in the dimensions or configuration. In addition, the invention may be used on other joints, such as a knee joint, where one part of the joint is held immobile and the other part of the joint can be moved with the device. 
   In an alternate embodiment of the device, indicated at  200  in  FIG. 12 , the bar  134  and strap  140  are absent. A resilient pad  135  is affixed to the upper surface of the upper plate  107  and preferably extends onto a portion of the base plate  104 , as shown in  FIG. 12 . The resilient pad  135  forms a cushion between the patient&#39;s neck or back and the upper plate  107 . The pad  135  may comprise two pads mounted to have a space between them to form a cradle for stabilizing a patient&#39;s spine on the upper plate. In such an embodiment, the pads  135  must be thick enough and positioned such that the patients back does not touch the upper plate  107 . 
   For extension the device  200  is positioned under the patient with the rear edge  104   b  of the device directed toward the patient&#39;s feet, with the patient&#39;s head extending beyond the upper plate  107  and the forward edge  107   a  of the upper plate  107  under the vertebra below the vertebra in need of repositioning. For flexion the device  200  is positioned under the patient with the forward end  104   a  of the device directed toward the patient&#39;s feet, with the patient&#39;s body resting on the upper plate  107  and the forward edge  107   a  of the upper plate  107  under the vertebra above the vertebra in need of repositioning. In this orientation the practitioner may, as required for the comfort of the patient, raise the rearward end  104   b  from the patient table  142  to bring the upper surface of the upper plate  107  more closely parallel to the surface of the patient table  142 . This may be accomplished by placing a spacer of the required thickness under the base plate. Such a configuration will also tend to bring the patient&#39;s body into a flexed position, which will simplify the adjustment. 
   For treatment of the lower joints and vertebrae of the spine, the device  200  is positioned with the forward edge  107   a  of the upper plate  107  under the joint to be treated, whether under the patient&#39;s back or pelvis, and activated as described above with reference to the neck vertebrae, for flexion or extension of the joint, as the case may be. 
   A further embodiment of the device, illustrated in  FIG. 5 , may include means for indicating the force required to overcome the resistance of the drop assembly  110 , i.e., the threshold force. The indication means may comprise a graduated scale  182  on the base plate  104  and an index  184  on the thumbscrew  122 . As the thumbscrew  122  is rotated, the index  184  moves over the scale  182 , indicating the amount of compression exerted by the thumbscrew  122  on the spring  126 , and thus the resistive pressure of the spring  126  on the bearings  120  and  128 . A more accurate, albeit more complex indication means may include a device configured to directly measure and indicated tension on the bearings. 
   From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications or combinations of the described embodiments may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
A spinal adjusting device having a base plate assembly with an upper plate assembly coupled thereto, the base plate assembly configured to permit the upper plate assembly to drop a predetermined distance when subjected to a predetermined force. The base plate assembly includes a coupling mechanism having a drop assembly that enables adjustment in the amount of predetermined force required to drop the upper plate assembly onto the base plate. A patient is placed with their neck supported at the vertebra adjacent to the vertebra in need of repositioning. The patient's cervical spine and skull are flexed or extended with sufficient force to cause the entire upper assembly to drop, facilitating repositioning of the target vertebrae.