Abstract:
An apparatus for lower back exercise has a support structure, a body support platform and a pendulum pivotably connected to the support structure below the body support platform for engaging the legs of a user. Actuators cause the pendulum to move upwardly or downwardly to either assist the movement of the legs of a user engaging the pendulum, or to resist motions of the pendulum initiated by the user. The body support platform may be tilted by an actuator to provide ease of mounting and dismounting the apparatus. Controls for the actuators are provided to allow a practitioner to monitor and adjust the assistance or resistance provided by the apparatus to the user. The apparatus thus avoids hyperextension of the back while providing strength conditioning with progressive intensity of work outs, especially for users injured or otherwise in poor condition.

Description:
BACKGROUND 
     1. Technical Field 
     This disclosure relates to an improved apparatus and method for lower back exercise. 
     2. Background 
     Back muscle and cartilage injuries, especially in the lower lumbar region of the back, are relatively common. Such injuries are especially common in individuals who, for one reason or another, have failed to maintain the conditioning and tone of the muscles that support the lower back. These muscles, the spinal erectors and hip flexors must be maintained in reasonable condition if such muscle and cartilage injuries are to be protected against. 
     Additionally, once injury has occurred, healing can be promoted by increasing the flow of blood to the injured muscles and the areas surrounding the injury. Unfortunately, the number and density of blood vessels in the lower back area is relatively low. However, exercise is believed by many to stimulate increased blood flow. A drawback to most forms of exercise is the risk or tendency of hyperextension of the already injured muscles thereby aggravating the injury rather than promoting healing of the muscles, cartilage and surrounding tissues. 
     U.S. Pat. No. 5,356,359, to Applicant Louis J. Simmons attempts to address these needs. The present application is an improvement over the apparatus disclosed in U.S. Pat. No. 5,356,359, as well as over the apparatus disclosed in Applicant&#39;s U.S. Pat. Nos. 8,529,413 and 6,491,607, all of which patents are incorporated into the present disclosure by reference in their entirety, but which are not admitted to be prior art by inclusion in this Background section. However, none of the previous attempts have completely met the exercise needs of individuals who have already sustained lower back injuries or whose lower back areas are too out-of-condition to be able to withstand rigorous exercise. In order for exercise to be of value, it must progressively increase in intensity. A common method of increasing the intensity of an exercise is through the use of increased resistance from static weight additions. However, adding weight to an exercise can increase the hyperextension of lower back muscles. Therefore, weight training is not generally recommended for those suffering from lower back muscle, tissue and cartilage injuries. 
     There is a need for an exercise apparatus that avoids hyperextension of lower back muscles while providing for conditioning and muscle tone, and which can increase local blood circulation to injured muscles and tissues in the lower back. There is also a need for an exercise apparatus that can permit progressive intensity of the workout to strengthen lower back muscles and tissues and provide increased blood flow to those areas, without increasing the hyperextension of lower back muscles. For persons not in good physical condition, there is a particular need for an apparatus that can assist the person with performance of the exercise, while still retaining the benefits of lower-back muscle conditioning. 
     SUMMARY 
     An apparatus for lower back exercise comprises a support structure, and the support structure further comprises a body support platform. A pendulum is pivotably connected to the support structure and hangs down therefrom. Thus the pendulum has a vertical plane of movement with respect to the support structure. A resistance transfer apparatus is pivotably connected to the pendulum. The resistance transfer apparatus pivots in a plane substantially parallel to the plane of movement of the pendulum while it is engaging the legs of a user exercising. At least one first actuator is connected to the pendulum to cause the pendulum to move upwardly or downwardly in its plane of movement to assist the movement of the legs of the user engaging the pendulum at the resistance transfer apparatus. A second actuator is connected to the pendulum to cause the pendulum to move upwardly or downwardly to exert resistance to movement of the user&#39;s legs initiated by the user. Controls are operably connected to the actuators effective to regulate the motion of the pendulum upwardly or downwardly while the user&#39;s body is disposed on the body support platform and the user&#39;s legs engage the pendulum. The actuators may be pneumatic, hydraulic, or electric, or some combination thereof. Controls for the actuators allow a practitioner to monitor and adjust the assistance or resistance provided by the apparatus to the user. The apparatus thus avoids hyperextension of the back while providing strength conditioning with progressive intensity of work outs, especially for users injured or otherwise in poor condition. 
    
    
     
       DRAWINGS 
       Non-limiting embodiments of the present disclosure are described by way of example in the following drawings, which are schematic and are not intended to be drawn to scale: 
         FIG. 1A  is a side view of an embodiment of the disclosed apparatus. 
         FIG. 1B  is a side view of an embodiment of the disclosed apparatus showing a means for applying assistance and resistance to the pendulum of the apparatus. 
         FIG. 1C  is a further side view of an embodiment of the disclosed apparatus, showing a means for tilting the body support platform. 
         FIG. 2  is a top view of an embodiment of the disclosed apparatus. 
         FIG. 3  is a rear view of an embodiment of the disclosed apparatus. 
         FIG. 4  is a top view of an embodiment of the disclosed apparatus, with the body support platform removed for clarity. 
         FIG. 5A  is a side view of the detail of the actuator mechanism of an embodiment of the disclosed apparatus. 
         FIG. 5B  is a schematic diagram of the forces exerted by the actuators of the disclosed apparatus. 
         FIGS. 6 through 10  show cycles of exercise using an embodiment of the disclosed apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is a novel improvement over the machines disclosed in the patents cited above in the Background Section and incorporated herein by reference (called “the incorporated patents”). The incorporated patents show embodiments of machines manufactured by Tee and Ell Weight Lifting and Exercise Enterprises, Inc., of Columbus, Ohio, and sold under the trademark REVERSE HYPER®. 
     In this application, the term “user” refers to the person who is engaging his or her body with the disclosed apparatus and using it for performance of exercises to strengthen and condition the muscles of the lower back. 
       FIGS. 1 through 3  show an embodiment  100  of the improved apparatus.  FIGS. 1A and 1B  are side views,  FIG. 2  is a rear view, and  FIG. 3  is a top view. Generally, support legs  110  are connected by support cross arms  120  (see  FIG. 3 ), and body support platform  130  to form a user support structure. A pendulum  160 , described below, depends from the user support structure. It is preferred that the body support platform  130  include padding for comfort. Handholds  140  for the user may optionally be provided. 
       FIG. 1A  shows means for providing assistance and resistance to the pendulum  160 , as discussed in detail below. For clarity, the side view of  FIG. 1B  omits the foregoing means from the depiction, and shows the support-platform actuator  255 , discussed in more detail below.  FIG. 1A  omits depiction of the support-platform actuator  255 . 
       FIG. 3  shows a pivot bar  150 , located below the body support platform  130 , that rotatably retains the pendulum  160 . For optimal implementation of the exercise method, the pivot bar  150  should be located at a point approximately below the waist of the person using the apparatus and at a vertical position near the body support platform  130 . 
     The pendulum  160  is rotatably retained on the pivot bar  150  on one or more bearings  155  fitted to the pivot bar  150 . The bearings  155  may be equivalently mounted on support cross arms  120  or elsewhere on the supporting structure to thereby rotatably retain the pivot bar  150 . In any embodiment, pendulum  160  is then freely pivotable about the pivot bar  150 , as shown, in a substantially vertical plane. 
     The pendulum  160 , as illustrated in  FIGS. 1 and 3 , is a composite structure. A resistance transfer apparatus  170  is pivotably attached to the pendulum  160  at a connector  180 . The resistance transfer apparatus  170 , as shown in  FIGS. 1-3 , preferably has two or more pads  190  extending laterally from the axis of the resistance transfer apparatus  170 , which pads  190  are preferably rotatably mounted, to thus comfortably retain the user&#39;s ankles as the exercise is executed. The resistance transfer apparatus  170  may retain the user&#39;s legs anywhere along their length, but the optimum position is at the ankles, as shown in  FIGS. 7-10 . It is convenient to provide additional padded supports  200  along the pendulum  160 , but nearer the pivot bar  150 , to give additional support to the user&#39;s upper legs. 
     As stated, many individuals, however, cannot perform the exercise without assistance. Such persons require an assisted lift of the legs, at least for the concentric portion of the lift. Users unable to lift their legs up can still go through the complete range of motion with the assistance. The eccentric portion of the movement, or the lowering of the legs, may be assisted by decreasing the assist provided for raising the legs in the concentric portion of the exercise. As will be discussed in more detail below, the provision of assistance to the user prevents the buildup of momentum as well as assisting out-of condition users to enter and complete the exercise. Also as discussed below, the range of motion is controlled by a practitioner and not by the user. 
       FIG. 4  is a top view of the prototypical embodiment  100 , with the body support platform  130  removed for clarity to show the means for moving the pendulum  160 . The body support platform  130  may pivot, as will be explained later, on body support rods  210  extending from either side of the frame  110 .  FIG. 4  further shows a control station  135  for controlling the motions of the pendulum  160 , as discussed below. 
     As further shown in  FIG. 4 , a first actuator  220  and second actuator  225 , cooperating together, provide assistance to the user in raising and lowering the user&#39;s legs, and a third actuator  230  provides resistance to the movements made by the user. First actuator  220  and second actuator  225  turn a gear set  240  with a crank arm  280  (shown in side view  FIG. 5A ). Equivalently, the gear set  240  could be a sprocket and chain. The gear set  240  rotates the pivot bar  150 , causing the pendulum  160  to move accordingly. The actuators  220 ,  225 , and  230  will be discussed in this disclosure as pneumatic, but may equivalently be electric or hydraulic. The embodiment illustrated uses two actuators, first actuator  220  and second actuator  225 , to obtain the force required to provide active assistance to the user. The reader should note, however, that in other embodiments only one such actuator  220 ,  225  for assistance will be needed, if a sufficiently powerful single actuator is adaptable to be mounted within the apparatus  100 . Also, the side view figures here will generally identify only first actuator  220  for clarity. 
       FIG. 5B  shows schematically the forces exerted by the first actuator  220  and second actuator  225  (or, alternatively, a single such actuator) on the pendulum  160  through the gear set  240 . Since the user&#39;s legs are constrained by the resistance transfer apparatus  170  connected to the pendulum  160 , the user&#39;s legs may either be assisted in their movement by the first actuator  220  and second actuator  225 , or their movement may resisted by movement of the third actuator  230 , depending on the pneumatic pressures communicated to the actuators  220 ,  225  according to settings made at the control panel  135 . 
     The disclosed improvements safely and effectively provide exercise benefits to those users who lack the strength or control to perform the exercise on their own, without assistance. This is accomplished by providing active assistance to the movement of the user&#39;s legs and back through all phases of the exercise. The active assistance is provided for raising the pendulum  160  with the user&#39;s legs engaged by means of the first actuator  220  and second actuator  225 , acting together upon the gear set  240 , turning pivot bar  150 . 
     The active resistance to the user&#39;s movements as the user attempts to move his legs back to the starting position shown in  FIG. 6 , is provided by third actuator  230 , also connected to turn pivot bar  150 . Generally, the third actuator  230  will be sufficiently powerful to provide the needed resistance without transmission of torque through a gear set. The first actuator  220  and the second actuator  225  (or a single such actuator), and the third actuator  230  are controlled by pneumatic valves (or hydraulic valves or electric motor controls in other embodiments) preferably located in a control station  135  adjacent to or connected to the frame  110  of the apparatus  100 . Preferably, the control station  135  is operated by a practitioner, such as a physician or a physical therapist. 
       FIG. 2  shows a top view of the controls located on a representative control panel  135 . An air pressure gauge  290  shows the amount of pressure applied to the actuators, and thus the amount of force exerted by the actuators, to allow the practitioner to note and record progress by the user in both lifting his or her legs and in applying resistance. A command switch  300  is provided to command either up or down movement of the pendulum  160 . A first lever switch  310  continuously varies the amount of pressure (and thus force) causing assisted movement (up or down), and a second lever switch  320  continuously varies the amount of pressure (and thus force) causing resistance to movement (up or down). 
     As shown in  FIGS. 6-10 , the resistance transfer apparatus  170  and its rotatable connection to the pendulum  160  permits the user&#39;s legs to move up to the horizontal and back past the vertical during the exercise. In this disclosure, the “vertical” position of a user&#39;s legs is substantially as depicted in  FIG. 6 . A “horizontal position of the user&#39;s legs is substantially as depicted in  FIG. 8 . A movement said to be “upward” or “upwardly” is a movement from the vertical position toward the horizontal position, and a movement said to be “downward” or “downwardly” is a movement from the horizontal position toward the vertical position. (Similar terms are used for the position of the pendulum  160 ). The static weight of pendulum  160  does not come into play or weight the user&#39;s ankles until the exercise is begun with the pendulum  160  vertical. 
       FIGS. 6-10  shown a cycle of exercise using an embodiment of the apparatus  100 .  FIG. 6  shows a starting position of the user&#39;s legs, engaging the resistance transfer apparatus  170 . In  FIGS. 7 and 8 , the user has raised his or her legs to the approximately horizontal position. In  FIG. 9 , the user has lowered his or her legs back to the starting position and pushed slightly past the starting position of  FIG. 6 ; thus the total range of motion is greater than 90 degrees. After the user has pushed the legs as far past the vertical as he or she can, the exercise begins again by contracting the muscles and pushing the legs back to the horizontal. Preferably, the range of motion allowed should be approximately at least 135 degrees. The exercise is then repeated the number of times desired.  FIG. 10  illustrates an embodiment wherein the support platform  130  may be tilted by means of actuator  255  as shown in  FIG. 1C , thus making it easier for a user to mount and start the exercise, also to dismount. Advantageously, the support platform  130  should allow a tilt of about 18 degrees. 
     The exercise is best performed as a smooth continuous action through the iterations. At all points in the exercise, the legs and correspondingly the affected muscles only push and are never pulled from one station to the next. The result is that hyperextension of muscles is avoided and the injured muscles of the lower back are permitted to receive an increase flow of blood. Additionally, in a user with an otherwise healthy lower back, the exercise builds up those lower back muscles thus avoiding future injury. 
     None of the description in this application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope; the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke paragraph six of 35 U.S.C. Section 112 unless the exact words “means for” are used, followed by a gerund. The claims as filed are intended to be as comprehensive as possible, and no subject matter is intentionally relinquished, dedicated, or abandoned.