Lumbar traction apparatus

Abstract

Lumbar traction apparatus comprising a pair of upper and lower U-shaped supports adapted to be attached to the upper and lower waist portions respectively of a patient undergoing treatment; a belt assembly associated with each of the supports for tightening them to the patient; a pair of laterally spaced apart traction control assemblies extending between the supports, each assembly having a vertically extending tube connected to one of the supports and a toothed rod telescopically mounted for reciprocation in the tube and connected to the other support, and a rotatable shaft carrying a pinion engaged with the teeth on the rod; and a ratchet drive mechanism associated with each traction control assembly for rotating the shaft carrying the pinion in one direction to move the rod relative to the tube thereby moving the supports apart and applying traction to the lower lumbar region of the patient.

Description

This invention relates to lumbar traction apparatus capable of stretching the lumbar region of a patient for the purpose of treating back disorders.

Relief of symptoms caused by degenerative disc disease with sciatic nerve involvement and radiating pain can be achieved in many cases using the lumbar traction apparatus disclosed in U.S. Pat. No. 2,835,247. In such apparatus, a pair of padded curved steel bars are strapped to a patient such that the bottom bar rests on the iliac crests of the patient and the top bar is situated at approximately the 8-9 dorsal levels. Once applied, the straps on the upper and lower bars are pulled tight and a pair of laterally spaced apart traction control assemblies extending between the supports are operated to separate the supports and apply traction to the patient.

Each traction control assembly has a toothed rod attached to the upper bar and telescopically received in a tube carried by the lower bar. A housing on each tube provides a mounting for a shaft on one end of which is a pinion that operatively engages the teeth on the rod and on the other end of which is a handwheel by which rotation of the shaft can be effected. By manually rotating the shaft in the proper direction, the rod may be moved relative to the sleeve such that traction can be applied to the bars separating them. The proper amount of traction applied is determined by the experience of the doctor treating the patient. Once the apparatus is so applied, the patient may walk around the treatment room actively for 25-30 minutes. The treatment also includes lordosis enlargement using a padded disc carried by the pair of tubes of the traction control assemblies and positioned in the back center of the apparatus can be screwed inwardly to the required distance.

One of the problems with this device is the mechanical difficulty in turning the handwheel and locking the wheel in place once the proper traction has been achieved. A large turning effort must be applied to the handwheel because it is coupled directly to the pinion and hence there is no mechanical advantage. Furthermore, the physical location of the handwheel makes it impossible for the patient himself to apply the traction and so precludes the use of the apparatus for self-treatment. In addition, the straps by which the pair of bars are attached to a patient are difficult to tighten securely, and difficult to loosen once securely tightened.

It is therefore an object of the present invention to provide a new and improved lumbar traction apparatus in which the above referred to disadvantages are substantially reduced or overcome.

According to the present invention there is provided a lumbar traction apparatus comprising a pair of upper and lower U-shaped supports adapted to be attached to the upper and lower waist portions respectively of a patient under treatment; a belt assembly associated with each of the supports for tightening them to the patient; a pair of laterally spaced apart traction control assemblies extending between the supports, each assembly having a vertically extending tube connected to one of the supports and a toothed rod telescopically mounted for reciprocation in the tube connected to the other support, and a rotatable shaft carrying a pinion engaged with the teeth on the rod; and a ratchet drive mechanism associated with each traction control assembly for rotating the shaft carrying the pinion in one direction to move the rod relative to the tube thereby moving the supports apart and applying traction to the lower lumbar region of the patient.

The provision of a ratchet drive mechanism for rotating the shaft carrying the pinion provides a substantial mechanical advantage which greatly facilitates the application of traction to a patient and provides for automatically maintaining the traction in effect by preventing reverse rotation of the shaft. In addition, the use of a ratchet drive mechanism admits of the possibility of actuation from either the front or rear of the patient to which the apparatus is applied thereby permitting either a doctor to administer the traction or the patient himself.

In the preferred embodiment of the invention, each belt assembly comprises a belt, one end of which is adapted to be selectively attached to one leg of the support with which the belt assembly is associated and the other end of which is wrapped around a rotatable shaft mounted on the other leg of the support, and a ratchet drive mechanism associated with each belt for rotating the shaft in one direction to wind the belt thereon and thereby tighten the support to the patient. This arrangement permits easy, rapid and positive tightening of the support to the patient.

It is further preferred that one or more of the ratchet drive mechanisms of the traction control assemblies or the belt assemblies comprise a ratchet wheel selectively coupleable to the shaft, and a ratchet wheel operator for rotating the ratchet wheel in response to actuation of the operator in a direction that rotates the shaft in the one direction when the shaft is coupled to the wheel. The ratchet wheel operator provides considerable leverage greatly facilitating the use of the apparatus.

It is further preferred that the ratchet wheel be freely mounted on the shaft for independent rotation, that each of the wheel and the shaft have adjacent notched faces that are alignable when the shaft and wheel have a fixed relative angular position, and that one end of a rod, coaxially mounted in the shaft for axial movement with respect thereto, be provided with a coupler engageable in the aligned notched faces for effecting selective coupling of the wheel to the shaft. A spring resiliently urging the rod in an axial direction maintains the coupler in the aligned notches. The user may directly retract the coupler from the notches against the action of the spring in order to decouple the ratchet wheel from the shaft; or, a mechanism may be provided to assist retraction of the coupler. When the coupler is retracted, traction is terminated by reason of the natural tendency of the patient's body to relax and drive the toothed rod downwardly as the pinion freely rotates.

An embodiment of the invention is illustrated by way of example in the accompanying drawings, wherein:

FIG. 1 is a perspective view of the apparatus according to the present invention showing it applied to a patient;

FIG. 2 is a side view of a traction control assembly by which traction is applied to the U-shaped supports;

FIG. 3 is a side view of the assembly shown in FIG. 2;

FIG. 4 is a section taken along the line IV--IV of FIG. 3;

FIG. 5 is a sectional view taken along the line V--V of FIG. 3 but showing the coupler aligned with but removed from the notches in the ratchet wheel and shaft;

FIG. 6 is a view partially in section showing the connection between the toothed rod and the upper support;

FIG. 7 is a top view of the ratchet drive mechanism used with the belt tightener;

FIG. 8 is a section taken along the line VIII--VIII of FIG. 7;

FIG. 9 is a sectional view of the lordosis pad assembly used with the apparatus; and

FIG. 10 is a top view of the assembly shown in FIG. 9.

Referring now to FIG. 1, reference numeral 10 designates lumbar traction apparatus according to the present invention. Such apparatus comprises a pair of upper and lower U-shaped supports 11 and 12 shown attached to the upper and lower waist portions, respectively, of a patient 13 undergoing treatment, a belt assembly 14 associated with each of the supports for tightening them to the patient, a pair of laterally spaced apart traction control assemblies 15 extending between the supports, and a ratchet drive mechanism 16 associated with each assembly 15 for moving the supports apart and applying traction to the lower lumbar region of the patient. The traction apparatus, includes a lordosis pad assembly 17 on the lower support 12 for controlling the forward convexity of the spine of the patient.

Each of the supports 11 and 12 are metallic, preferably steel, and are curved and provided with foam padding so as to comfortably fit the patient. In order to provide a proper location for the lordosis pad assembly 17, the closed central portion of the lower support is curved downwardly as shown in FIG. 1.

Each belt assembly 14 may comprise a standard automobile seat-belt strap 18 one end of which is provided with a conventional seat-belt buckle (not shown) that may be selectively attached to a conventional mating buckle catch plate (not shown) fixed to one leg of the support. Alternatively, assembly 14 may comprise a web of suitable material having at one end, any type of catch or connector by which it can be connected releasably to the one leg of the support. The other end of the belt 18 is wrapped around a rotatable shaft 19 (see FIG. 8) mounted on a bracket 20 connected to the other leg of the support. In addition, each belt assembly also includes a ratchet drive mechanism 21 by which the shaft 19 may be rotated in one direction to wind the belt thereon and thereby tighten the support on the patient.

In preparation for using apparatus 10, a padded cover 22 may be applied to the patient around his lower waist region, and the lower support 12 is positioned so as to rest on the iliac crests of the patient while the upper support is positioned at approximately the eighth or ninth dorsal levels. When so positioned, each of the supports may be securely attached to the patient by connecting the buckle on the belt associated with the support to the buckle catch plate on the support, and then operating the ratchet drive mechanism 21 for the purpose of winding the belt about the shaft 19 so as to tighten the support to the patient.

Referring now to the traction control assemblies 15, each comprises a vertically extending tube 22 connected by a clamp 23 to the lower support 12, a toothed rod 24 (see FIGS. 2 and 3) telescopically mounted for reciprocation within tube 22 and connected to the top support 11 by a connector member 25 (see FIG. 6), and a rotatable shaft 26 (see FIG. 5) mounted in a housing 27 clamped to tube 22 and carrying a pinion 28 engaged with the teeth 29 on the rod.

Ratchet drive mechanism 16, shown in detail in FIGS. 2 and 3, is employed for rotating the shaft 26 in a direction such that the rod 24 is moved upwardly within tube 22 for the purpose of moving the support 11 relative to support 12 and applying traction to the lower lumbar region of the patient.

Bracket 23 shown in detail in FIG. 4 has an arcuate shaped base 30 that conforms to the curvature of the lower support 12 and is secured thereto by suitable bolts 31 as shown in FIG. 3. Integral with the base 30 is a block 100 containing an axially directed aperture 32 of a size to slidably receive tube 22, there being a radially directed slot 33 connecting with bore 32 for the purpose of providing action when the bolt 34 is tightened. In this manner, tube 22 may be clamped to bracket 23 at any selected elevation of the tube.

Referring now to details of bracket 25 shown in FIG. 6, this bracket is likewise provided with a curved base 34 which conforms to the curvature of the upper support 11. Screws 35 are provided for the purpose of securely attaching the bracket 25 to the upper support such that the axial bore 36 within bracket 25 is aligned with the axial bore 32 in the bracket 23. Bore 36 is blind and slidably receives the upper free end of toothed rod 24 which is counter-bored to receive a compression spring 37 that is interposed between the rod 24 and the closed end of bore 36. Adjacent the counterbored end of rod 24 is a circumferential groove 38 into which fits the free end of locating screw 39 that passes through the bracket 25. The axial length of the groove 38 is somewhat greater than the axial dimension of the free end of screw 39 to provide for limited vertical movement of the bracket 25 relative to the rod 24 under the influence spring 37. By reason of this arrangement, "floating" action of the upper support 11 is provided so that it can accommodate limited movements of the body of the patient wearing the apparatus after traction has been established and thus will be reasonably comfortable.

The ratchet drive mechanism 16 associated with the traction control assemblies 15 and the ratchet drive mechanisms 21 associated with the belt assemblies 14 are of similar construction and operate in the same manner. Referring first to the ratchet drive mechanism 16, it comprises a ratchet wheel 40, a ratchel wheel operator 41 and means for selectively coupling the ratchet wheel to the shaft 26 which can be rotated in the direction for raising rod 24 in response to actuation of the operator. Shaft 26 is rotatably mounted within housing 27 and is held against axial movement by the abutment of an end face of pinion 28 with a counter-bored hole 42 in the housing, on eht one hand, and the abutment of one axial end of the shaft 26 with the counter-bored hole in plug 43 that slidably fits into the counter-bore 42 and is held therein by set screw 44. The opposite end of shaft 26 projects from housing 27 and terminates in a head 45 which overlies and engages axial end face 46 of ratchet wheel 40 retaining the latter between the head and the housing 27 but permitting the ratchet wheel to freely rotate relative to the shaft. The axial end face 46 of the ratchet wheel and the head 45 of the shaft 26 are provided with notches 47 and 48, respectively. Such notches can be aligned when the shaft and the ratchet wheel have a predetermined relative angular position. FIG. 5 shows the relative angular position at which the notches 47 and 48 are in alignment.

The ratchet wheel operator 41 comprises a pair of plates 49 and 50 each of which has circular holes 51 rotatably receiving the hub of ratchet wheel 40 on each side of its toothed periphery 52. A connector portion 53 (see FIG. 3) is rigidly attached to each of the connector plates for forming a unitary operating handle containing a drive pawl 54 pivotally pounted between the plates and operatively engaged with the toothed periphery 52 of the ratchet wheel. A torsion spring 55 is also mounted between the plates 49 and 50 and engages the pawl 54 for the purpose of urging the free end of the pawl into the toothed periphery of ratchet wheel 40. As shown in FIG. 2, clockwise rotation of the connector portion 53 will impart a clockwise rotation to the ratchet wheel 40. Stop pawl 56 rotatably mounted on a pin carried by member 27 operatively engages the toothed periphery of the ratchet wheel and will prevent counter clockwise rotation of the ratchet wheel as shown in FIG. 2 upon counter clockwise rotation of the connector portion 53 of the handle. Thus, oscillatory movement of the handle will impart unidirectional rotation to the ratchet wheel.

The means by which the ratchet wheel may be selectively coupled to shaft 26 includes the notches 47 and 48 on the ratchet wheel and shaft respectively, and the rod 60 coaxially mounted within a central bore in shaft 26, a coupler 61 mounted on one end of rod 60 and a compression spring 62 mounted on the other end of the rod. The end of rod 60 carrying the spring 62 is headed and fits into a counter-bored hole 63 contained within the shaft 26. The coupler 61 is threaded onto the free end of the rod 60 so as to be non-rotatably mounted thereon. Coupler 61 is circular in shape and has a knurled grip 64 and a central rib 65 facing toward the notched end faces of the shaft 26 and wheel 40. The dimension of the rib 65 is such as to permit the rib to slidably enter within notches 47 and 48 when they are in their aligned position shown in FIG. 5. In such position, the rib 65 will enter the notches by reason of the action of spring 62. The spring thus resiliently urges the rod in an axial direction that will seat the rib of the coupler in the notches when the shaft and wheel reach their relative angular positions at which the notches are aligned. When rib 65 is contained within notches 47 and 48, rotation of wheel 40 is transferred to shaft 26 through action of the notches 47 and 48 and the rib 65. The connection between wheel 40 and shaft 26 is interrupted when the knurled grip 64 is grasped and the rod 60 is pulled outwardly against spring 62 to withdraw rib 65 from notches 47 and 48. Misalignment of the rib with the notch 48 in the shaft 26 will completely decouple the ratchet wheel from the shaft. In this condition, the shaft 26 is free to turn independently of the ratchet wheel, and this will be the case when the rod 24 is under pressure caused by the patient in traction.

In order to apply traction to the patient after the supports are properly attached to the patient, the technician would first couple the ratchet wheels of each traction control assembly 15 by rotating the handle associated with each mechanism 16 until the notch in wheel 40 is aligned with the notch in shaft 26. He would then rotate the rod 60 by grasping the knurled grip 64 until the rib 65 is aligned with the aligned notches 47 and 48. When this alignment occurs, the rib 65 will snap into the aligned notches by reason of the action of spring 62. At this point, both of the traction control assemblies will be engaged and the operator may then oscillate each of the handles associated with the assemblies for the purpose of elevating the upper support relative to the lower support until the desired degree of traction is achieved. A gauge 57 may be employed for the purpose of providing a visual read-out of the degree of traction. After each stroke of the handle which moves the pinion 28 in a direction that raises rod 24, the traction applied is maintained by reason of the presence of pawl 56. Upon the completion of treatment, the operator merely withdraws the rod 60 against the action of spring 62 until rib 65 is is withdrawn from notches 47 and 48 whereupon the downward axial pressure on rod 24 exerted by the patient will automatically lower the rod 24 driving the pinion 28 and rotating the shaft 26 independently of the ratchet wheel 40.

By reason of the ratchet and pawl arrangement shown and described herein, the operating handle of the ratchet can be moved through an arc limited only by the presence of pawl 56. Such arc is at least 180.degree. in magnitude permitting the handle to be actuated either from the rear of the patient by a technician, or from the front of the patient by the technician or by the patient himself.

Referring now to ratchet mechanism 21 shown in FIGS. 7 and 8, it comprises a ratchet wheel 70, a ratchet wheel operator 71 for rotating the ratchet wheel, and means for selectively coupling the ratchet wheel to the shaft 19 so that the actuation of the operator 71 in a particular direction rotates the shaft 19 in a direction that will wind the seat belt onto the shaft 19 when the shaft is coupled to the ratchet wheel 70. Shaft 19 is in the form of a hollow tube that extends between a pair of spaced legs 72 of bracket 20 which is attached to the upper support 11 by means of suitable rivets or screws 73. Shaft 19 is rotatable within the legs 72 and is held in against axial movement in one direction by means of a retainer ring 74 engaged with the lower legs 72. The opposite end of shaft 19 is provided with a head 75 which overlies the end face 76 of the ratchet wheel 70 and retains the same against the upper legs 72 such that the ratchet wheel is freely rotatable on the shaft 19. Head 75 and the end face 76 of the ratchet wheel are provided with a pair of mating notches 77 (see FIG. 7) which are alignable when the shaft and the ratchet wheel have a predetermined relative angular position.

The ratchet wheel operator 71 comprises a pair of plates 78 and 79 each having aligned circular holes rotatably receiving the hub of ratchet wheel 40 on each side of its toothed periphery, and a connector plate 80 rigidly connecting the plates together and forming an operating handle. Oscillatory movement of the handle will cause drive pawl 81 pivotally connected between the plates 78 and 79 to operatively engage the toothed periphery of ratchet wheel 70. A torsion spring 82 engaged with the pawl 81 urges the free end thereof into the toothed periphery so that rotation of the handle of the operator in one direction will drive the ratchet wheel in that direction whereas rotation of the handle in the opposite direction will have no effect on the ratchet wheel. A latching pawl 83 pivotally mounted in a pin carried by the legs 72 has a free end that operatively engages the toothed periphery of the ratchet wheel and serves to prevent rotation of the ratchet wheel in a direction opposite to the direction in which the rotation of the handle will drive the ratchet wheel.

Coaxially mounted within the head 75 of the shaft 19 is a rod 84 on the inner headed end of which is a compression spring 85 which urges the coupler 86 on the opposite end toward the notches 77. A rib on the coupler 86 (not shown) is of a dimension that may slidably enter aligned notches 77 for the purpose of coupling the shaft 19 to the ratchet wheel. The coupling is identical to the coupling achieved with the ratchet mechanism shown in FIG. 5.

Frictionally received within the inner bore of shaft 19 is an inner tubular member 87 having a knurled head 88 projecting from the bore of shaft 19 and limiting axial movement of the member 87. Slots 89 and 90 in shaft 19 and member 87 respectively are alignable depending upon the angular position of member 87. Such angular position is determined by a technician merely by grasping and rotating the knurled head 88. When the slots 89 and 90 are aligned, the free end of a seat belt may be threaded through the slots so that the free end terminates within the recess formed by member 87. Upon rotation of the handle of the ratchet wheel operator, shaft 19 will rotate in one direction winding the belt upon the shaft for the purpose of tightening the belt. Thus, the upper and the lower supports 11 and 12 of the present invention may be securely fastened to the body of the patient by first aligning the rib of coupler 86 with the notches 87 to permit the rib to seat therein followed by applying an oscillatory movement to the handles to wind the belts upon the shafts 19.

When securely attached to the body of a patient, the webs of belt 18 are under considerable tension and the resultant torque on shaft 19 tightly wedges the rib of coupler 86 into engagement with the notches 77. In many cases, it is very difficult to directly withdraw the rib from the notches 77 by grasping coupler 86. Furthermore, a sudden release of the belts, such as would result from withdrawal of the rib from the notches, would uncomfortably jolt the patient, possibly injuring him. It is therefore essential to loosen the belts, gradually, in a controlled manner. Such controlled loosening of the belts is achieved by proper manipulation of operating handle 100 on pawl 83 and the handle of operator 71.

In removing the apparatus from the patient in a controlled manner, the attendant grasps the handle of operator 71 in one hand, holding it firmly in a fixed angular position, as he pushes with the other hand on the handle 100 pivoting it until the tooth of pawl 83 is retracted from ratchet wheel 70. Upon such retraction, the torque on shaft 19 is transferred to the handle of operator 71 which the attendant can rotate slowly in the direction opposite to the direction in which it had been moved to apply tension, gradually relieving the tension in the web of the belt and the pressure on the patient. When there is some slack in the web, the belt can be disconnected by first unwinding the web from shaft 19. For this purpose, it is necessary to retract the rib on coupler 86 from the notches 77.

Retraction of the rib is assisted by reason of the provision of auxiliary lifting lever assembly 101 which comprises a lever 102 mounted on a stud 103 that may form an extension to the pivot for pawl 81. Lever 102, shown in phantom lines in FIG. 7, has a fork-shaped head 104 that fits beneath the flange of coupler 86 and an integral handle 105 inclined upwardly from the plane of head 104 as shown in FIG. 8. Stud 103 passes through an enlarged aperture in head 104 such that limited tilting movement of the handle 105 is possible for the purpose of causing the head 104 to pry the coupler 86 upwardly even when the rib of the latter is tightly wedged in the notches 77.

In order to withdraw the rib of coupler 86 from the notches 77, handle 105 of the lever assembly 101 is pushed downwardly toward the handle of operator 71 as indicated by arrow 106 in FIG. 8 until the head 104 moves the coupler 86 axially sufficiently far to disengage the rib from the notches. With the belt now loosened, it can be unbuckled and the apparatus removed from the patient. Mechanism 21 is now in condition for use with the next patient.

In order that the belts may be as comfortable as possible when the supports are attached to the patient, it is preferred for the brackets 20 of the belt assemblies to be pivotally mounted on its support. Thus, each bracket 20 is pivotally mounted on a pin 73 carried by a support, and an additional pin 107, carried by each support, passes through an arcuate shaped hole 108 in the bracket 20 for the purpose of effecting limited pivotal movement of the bracket. This arrangement provides for the belt to be "self-centering" and conforms the belt position to that most suitable for the patient.

Referring now to the lordosis pad assembly 17 shown in detail in FIG. 9 and 10, this assembly comprises a bracket 90 securely bolted to the lower support 12 and extending upwardly toward the upper support 11. Bracket 90 is bifurcated by reason of central slot 91 that receives a threaded nut 92 provided with a pair of opposite grooves respectively engaged with opposed surfaces of the slot 91 of bracket 90. The dimensional relationship between the grooves in the nut and the slot in the bracket is such that a light press fit exists such that the nut remains where it is placed, and light finger pressure is required to displace the nut in the slot. This arrangement will permit a technician to raise or lower the nut 92 in the slot 91 until the axis of the nut is properly aligned to provide the required curvature to the lower spine. In order to effect such curvature, a threaded shaft 93 received within the nut 92 carries at one end a padded disc 94 for contacting the patient's back and with a handwheel 95 at the other end for effecting rotation of the shaft 93. In the preferred arrangement, the padded disc 94 is connected to the shaft 93 by way of a ball joint connection 95. Manual rotation of the handwheel 95 will thread the shaft 93 inwardly or outwardly depending upon the direction of rotation of the handwheel thus moving the padded disc 94 relative to the bracket 91. The lordosis pad assembly 17 just described is optional with the supports 11 and 12.

Claims

I claim:

1. Lumbar traction apparatus comprising a pair of upper and lower U-shaped supports adapted to be attached to the upper and lower waist portions respectively of a patient undergoing treatment; a belt assembly associated with each of the supports for tightening them to the patient; a pair of laterally spaced apart traction control assemblies extending between the supports, each assembly having a vertically extending tube connected to one of the supports and a toothed rod telescopically mounted for reciprocation in the tube and connected to the other support, and a rotatable shaft carrying a pinion engaged with the teeth on the rod; and a ratchet drive mechanism associated with each traction control assembly for rotating the shaft carrying the pinion in one direction to move the rod relative to the tube thereby moving the supports apart and applying traction to the lower lumbar region of the patient (1), wherein the belt assembly associated with each of the supports comprises a belt, one end of which is adapted to be releasably attached to one leg of the support and the other end of which is wrapped around a rotatable shaft mounted on the other leg of the support, and a ratchet drive mechanism associated with each belt for rotating the shaft in one direction to wind the belt thereon and thereby tighten the support to the patient.

2. Lumbar traction apparatus according to claim 1 wherein one or more of the ratchet drive mechanisms of the traction control assembly or the belt assembly comprises a ratchet wheel selectively coupleable to the shaft, a ratchet wheel operator for rotating the ratchet wheel in response to actuation of the operator in a direction that rotates the shaft in the one direction when the shaft is coupled to the wheel.

3. Lumbar traction apparatus according to claim 2 wherein the ratchet wheel is rotatably mounted on the shaft and each of the ratchet wheel and shaft have adjacent notched faces that are alignable when the shaft and wheel have a predetermined relative angular position, and including a rod coaxially mounted in the shaft for axial movement therein, a coupler mounted on one end of the rod selectively engageable in the aligned notched faces for effecting the coupling of the wheel to the shaft, and a spring for resiliently urging the rod in an axial direction that urges the coupler toward the aligned notched faces.

4. Lumbar traction apparatus according to claim 2 wherein the ratchet wheel operator comprises a pair of plates having circular holes rotatably receiving the hub of the ratchet wheel on each side of its toothed periphery, and a connector portion rigidly connecting the plates and forming an operating handle, oscillatory movement of the handle imparting unidirectional rotation to the ratchet wheel.

5. Lumbar traction apparatus according to claim 4 wherein the free end of a spring loaded pawl operatively engages the toothed periphery of the wheel for limitating rotation thereof in the direction opposite to the direction in which the handle can rotate the wheel.

6. Lumbar traction apparatus comprising a pair of upper and lower U-shaped supports adapted to be attached to the upper and lower waist portions respectively of a patient undergoing treatment; a belt assembly associated with each of the supports for tightening them to the patient; a pair of laterally spaced apart traction control assemblies extending between the supports, each assembly having a vertically extending tube connected to one of the supports and a toothed rod telescopically mounted for reciprocation in the tube and connected to the other support, and a rotatable shaft carrying a pinion engaged with the teeth on the rod; and a ratchet drive mechanism associated with each traction control assembly for rotating the shaft carrying the pinion in one direction to move the rod relative to the tube thereby moving the supports apart and applying traction to the lower lumbar region of the patient, and wherein the rods are connected to the upper supports and the tubes are connected to the lower support, each connection of the rod to the upper support being by way of a pin extending into an axially elongated slot in a rod, and a spring interposed between the free end of the rod and the upper support to provide for limited relative movement between the upper support and the rods to cushion the upper support against the patient's body.

7. Lumbar traction apparatus comprising a pair of upper and lower U-shaped supports adapted to be attached to the upper and lower waist portions respectively of a patient undergoing treatment; a belt assembly associated with each of the supports for tightening them to the patient, a pair of laterally spaced apart traction control assemblies extending between the supports, each assembly having a vertically extending tube connected to one of the supports and a toothed rod telescopically mounted for reciprocation in the tube and connected to the other support, and a rotatable shaft carrying a pinion engaged with the teeth on the rod; and a ratchet drive mechanism associated with each traction control assembly for rotating the shaft carrying the pinion in one direction to move the rod relative to the tube thereby moving the supports apart and applying traction to the lower lumbar region of the patient, and including a lordosis enlarging pad assembly adjustably positionable in a generally vertical slot connected to the lower support and adapted to engage the desired level of the intermediate portion of the back of a patient for controlling the forward convexity of his spine.

8. Lumbar traction apparatus according to claim 7 wherein the lordosis enlarging pad assembly includes a vertically slotted plate extending upwardly from the bottom support, and a nut closely fitting but slidably carried within the slotted plate and having a threaded hole for receiving a threaded shaft to one end of which is attached the padded disc for contacting the patient's back and to the other end of which is attached a handwheel for effecting rotation of the threaded shaft.

9. Lumbar traction apparatus according to claim 8 wherein the disc is connected to the threaded shaft by a ball-joint.

10. Lumbar traction apparatus according to claim 5 wherein the spring loaded pawl has an operating handle by which the pawl can be selectively disengaged from the toothed periphery of the wheel to facilitate release.

11. A ratchet drive mechanism for lumbar traction apparatus comprising a pair of upper and lower U-shaped supports adapted to be attached to the upper and lower waist portions respectively of a patient undergoing treatment; a belt assembly associated with each of the supports for tightening them to the patient; a pair of laterally spaced apart traction control assemblies extending between the supports, each assembly having a vertically extending tube connected to one of the supports and a toothed rod telescopically mounted for reciprocation in the tube and connected to the other support, and a rotatable shaft carrying a pinion engaged with the teeth on the rod; and a ratchet drive mechanism associated with each traction control assembly for rotating the shaft carrying the pinion in one direction to move the rod relative to the tube thereby moving the supports apart and applying traction to the lower lumbar region of the patient, and comprising a housing having a first bore for reciprocably mounting a toothed shaft and a second bore transverse to the first bore for rotatably mounting a shaft to which a pinion is attached so as to be operatively engaged with the teeth of the rod, a ratchet wheel rotatably mounted on the shaft and having a notched end face adjacent a correspondingly notched end face on the shaft, a rod coaxially mounted on the shaft for axial sliding movement and carrying a coupler on one end seatable within the notches in the end faces of the shaft and the ratchet wheel when the latter are aligned, and a spring acting on the rod carrying the coupler for urging the same into the aligned notches.

12. A ratchet drive mechanism according to claim 11 including a ratchet wheel operator comprising a pair of plates having circular holes rotatably receiving the hub of the ratchet wheel on each side of its toothed periphery, and a connector portion rigidly connecting the plates for forming a handle by which unidirectional rotation can be imparted to the ratchet wheel in response to oscillatory movement of the handle.