Patent Publication Number: US-6991591-B1

Title: Hip flexor inhibiting abdominal training device

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application incorporates by reference U.S. patent application Ser. No. 09/439,804, filed 12 Nov. 1999, and claims the benefit of U.S. Provisional Application 60/369,487, filed 3 Apr. 2002 under 35 USC §119(e), also incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to exercise devices and, in particular, this invention relates to devices for exercising a user&#39;s abdominal muscles. 
   2. Background 
   During muscle training, it is difficult to isolate abdominal muscles from the hip flexors so as to achieve maximal overload and lower back health. A common solution of the prior art is avoiding hip flexion, or sit-ups, by performing only foreword spinal flexion, or by crunches. However, this practice is only marginally effective because eliminating movement in the hip joint does not inhibit the hip flexors. It is well accepted that a muscle contraction in the abdominal muscles will cause a corresponding contraction of adjacent muscles or the hip flexors. (Sherrington&#39;s Law of Irradiation) Persons with weak abdominal muscles rely on their hip flexors, even when performing crunches. The stronger hip flexors are recruited first. These hip flexors pull on the lumbar spine causing the back to hyperextend if the trainee&#39;s abdominal muscles are not strong enough to counterbalance this pull. Previous attempts to solve the problem of abdominal isolation involved making the crunch stricter. However, none of these approaches has effectively enabled an exercising person to effectively isolate his or her abdominal muscles because they have not addressed the neurological aspect of the problem of abdominal isolation. Moreover, none of these devices has indicated to a person that incorrect technique is being used during an exercise experience. 
   SUMMARY 
   This invention substantially meets the aforementioned needs of the industry by providing an exerciser which effectively isolates abdominal muscles during an exercise experience and indicates when the exercise is being improperly performed. 
   The invention is directed to equipment for strengthening and toning abdominal muscles. The present invention overrides undesirable contraction of corresponding muscle groups and inhibits the hip flexors during abdominal contraction with another physiological phenomenon, Reciprocal Inhibition (also one of Sherrington&#39;s Laws). When a muscle contracts, its antagonist relaxes. In the context of the present exerciser, contraction of the hip extensors inhibits the hip flexors, thereby effectively isolating the abdominals and relieving lower back stress. 
   And exerciser of the present invention is provided. The exerciser may include a leg rest and a main frame assembly. The leg rest may have a first frame portion separated at substantially orthogonal bends from a second frame portion and a third frame portion. A first hinge member may be present at ends of the second and third frame portions. The main frame assembly may be in mechanical communication with the leg rest assembly and may have first and second tubing portions, each of the first and second tubing portions with first and second ends. The first end of the first and second tubing portions may terminate in a second hinge member. A second ends of the first and second tubing portions may be joined at an apex. Each of the second and members are matable with one of the first and members of the second and third frame portions via hinge members. A weight may be mounted to the exerciser proximate the apex formed by joined first and second tubing portions. 
   A method of exercising a person&#39;s abdominal muscles is provided. In the provided method an exerciser is supinely disposed on a substantially flat surface. The exerciser may include a leg rest assembly in rigid mechanical communication with a weighted main frame. The method may include exerting a downward force on the leg rest assembly and contracting the person&#39;s abdominal muscles. The downward force on the leg rest assembly is exerted until the heels and balls of the person&#39;s feet contact the flat surface, thereby displacing the main frame from resting on the flat surface. When the person contracts the person&#39;s abdominal muscles, the heel and ball of the person&#39;s feet are maintained in contact with the flat surface. 
   There is also provided a method of making an exerciser. The method may include: forming a first end and a second end in a tubing piece, thereby defining a leg rest assembly with a first member, a second member, and a third member. The second and third members may generally transversely extend from the first member; obtusely bending a third and a fourth tubing piece; joining a first end of each of the third and fourth tubing pieces at an apex; installing a first hinge member at an end of each of the second member and the third members; and installing a second hinge member at a second end of the third and fourth tubing pieces. 
   These and other objects, features, and advantages of this invention will become apparent from the description which follows, when considered in view of the accompanying drawings. 
   A detailed description of the present invention is depicted in the accompanying figures, which are intended to be only illustrative of the present invention and are not contemplated to limit the scope thereof. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the present exerciser; 
       FIG. 2  is another perspective view of the present exerciser; 
       FIG. 3  is an exploded view of the exerciser of  FIG. 1 ; 
       FIG. 4  is a perspective view of a female coupler and a male coupler operably present in the exerciser of  FIG. 1 ; and 
       FIGS. 5   a – 5   d  depict a person exercising with the exerciser of  FIG. 1 . 
   

   It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit the scope thereof. 
   DETAILED DESCRIPTION 
   Any references to such relative terms as proximal and distal, top and bottom, inboard and outboard, or the like are intended for convenience of description and are not intended to limit the present invention or its components to any one positional or spatial orientation. All dimensions of the components in the attached figures may vary with the potential design and the intended use of an embodiment of the invention without departing from the spirit and scope thereof. 
   Each of the additional features and methods disclosed herein may be used separately or in conjunction with other features and methods to provide improved exercisers and methods for using and making the same. Representative examples of the teachings of the present invention, which examples utilize many of these additional features and methods, will now be described in detail with reference to the drawings. This detailed description is intended merely to teach a person of ordinary skill in the art further details for practicing aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, specific combinations of features and methods disclosed in the following detailed description may not be necessary to practice the invention in its broadest sense and are instead taught merely to particularly describe representative embodiments of the invention. 
   The present exercise device effectively isolates a person&#39;s abdominal muscles during an exercise experience. One consideration heretofore unrecognized when seeking to isolate a person&#39;s abdominal muscles is the role performed by the person&#39;s hamstring and related muscles. Hamstrings have two functions: hip extension and knee flexion. When the hamstrings are used as hip extensors, the hamstrings contract synergistically with the gluteals. In the context of the Janda sit-up, this phenomenon means that the trainee&#39;s heels will be pressing against the floor. When the hamstrings act as knee flexors, the hip flexors also tend to become activated. In the context of the Janda sit-up, this phenomenon dictates that the trainee&#39;s heels will be dragging towards the trainee&#39;s hips, or vice versa, especially when the trainee is struggling to complete the exercise movement. When the hip flexors are activated, the purpose of the exercise is defeated. Hence, it is imperative to enforce the hip extension functions of the hamstrings. With the present non-anchored active resistance, the trainee has a flexor inhibiting abdominal training device, which accomplishes hip extension of the hamstrings by providing the trainee with immediate feedback when the trainee performs a knee flexion/hip flexion-rather than a hip extension. If the exercise is performed incorrectly, the present device will be dragged toward the trainee&#39;s hips or the trainee will be dragged toward the device even though rubber or other friction-increasing material is applied to the pivot points. 
   The present device also provides another type of feedback to disencourage hip flexor contraction. The foam rollers of the present device press up against the trainee&#39;s calves, thereby tending to force the trainee&#39;s feet off the floor. When the trainee attempts to keep the trainee&#39;s feet flat on the floor, the trainee must accomplish this by activating the trainee&#39;s hip extensors. The trainee&#39;s feet coming off the floor, especially near the top of the movement, provides feedback that the trainee&#39;s hip extensors are not sufficiently activated, thus enforcing the proper form in another fashion. 
   One embodiment of the present exerciser is depicted in the figures generally at  100  and, referring to  FIGS. 1–3 , includes a leg rest assembly  104 , a main frame assembly  106 , a retainer such as a spring collar  108 , a locking device such as locking tubes  110  (in combination with hinge members such as male and female couplers disposed on the leg rest assembly  104  and the main frame  106 , infra), and a weight ( FIGS. 5   a – 5   c ). The leg rest assembly  104  of this embodiment includes respective first, second, and third members  116 ,  118 , and  120  and optionally at least one padding device such as a pair of foam pads  122 . The foam pads may be attached to the pipes or may rotate freely. Freely rotating pads may enforce stricter exercise performance, as they demand that the trainee pushes against them at a very precise angle; failure to do so will make the trainee&#39;s calves slip. A stricter exercise performance is understood to mean that the trainee&#39;s target muscle groups, e.g., abdominals, experience more adaptive overload. The second and third members  118  and  120  are unitarily (or otherwise integrally) joined to the first member  116  by bends  124  and  126 , respectively. Female couplers  127  and  128  are inserted and held, e.g., by friction at the ends of respective second and third members  118  and  120 . In the embodiment shown, the bends  124  and  126  are oriented transversely, e.g., at right angles (+/−5, 10) degrees, with respect to the first member  116  and may be characterized by radiuses of about 2.75 (+/−0.5, 1.0) inches. Also in the embodiment depicted, the first member  116  is about 15.5 (+/−1.0) inches and the second and third members  118  and  120  are about to 9.5 (+/−0.5, 1) inches, excluding portions of the bends  124  and  126 . If present, the foam pads  122  are made from a foamed synthetic resin, e.g., foam rubber. Other suitable resins may be identified by a person of ordinary skill in the art with out undue experimentation from the Handbook of Plastics, Elastomers, and Composites, Third Edition, herein incorporated by reference. 
   The main frame assembly  106  has a pair of main frame members  130  and  132  and a cap  134 . The respective main frame members  130  and  132  unitarily (or otherwise integrally) include first portions  138  and  140  and second portions  142  and  144  joined at obtuse bends  146  and  148 , respectively. The second portions  142  and  144  terminate in male couplers  150  and  152 . In the embodiment shown, the bends  146  and  148  are about 110 (+/−5) degrees and are described by radiuses of about 6 (+/−0.5) inches. Also in the embodiment depicted, the first and second portions  138  and  140  are about 20 (+/−0.5, 1) inches in length. The main frame members  130  and  132  are fixed together at an apex, e.g., by welding connectors (e.g., rivets, bolts/nuts), or the like. Alternatively the main frame members  130  and  132  may be fixed together by the cap  134 . The cap  134 , in turn, includes a cylindrical portion  156 , an optional top cover  156 , and a lower flange  160 . The cylindrical portion  156  may be about 4 (+/−0.5, 1) inches in length and have a radius of about 1 (+/−0.5) inch. The cap  134  and flange  116  may have dimensions substantially similar to those of a similar device for mounting Olympic-size barbells. 
   The locking tubes  110  may be about 6 (+/−0.5, 1.0) inches long and have a radius of about 0.5 (+/−0.25) inch. The spring collar  108  includes a pair of handles  164  extending from a generally circular spring member  166 . Forcing the handles  164  toward each other biases the spring element  166 , thereby increasing the diameter of the spring element  166 . The spring element  166  is dimensioned to fit snugly about the circumference of the cylindrical element  156 , especially when in an unbiased position. 
   The present male and female couplers are present at the ends of the leg rest assembly first and second members  118  and  120  and at the ends of the main frame second portions  142  and  144 , e.g., by being forced inside the tubings from which these structures are constructed and frictionally held therein. While the present female couplers are shown as being present in the leg rest assembly and the present male couplers as being present in the main frame, it should be appreciated that male couplers could be used with the present leg rest assembly and that female couplers would be used with the present main frame. It should also be recognized that a person of ordinary skill in the art would readily identify several equivalent structures to the present male and female couplers without undue experimentation. Referring to  FIG. 4 , the female couplers  127  and  128  and the male couplers  150  and  152  each display a first surface, such as a lateral surface  170 , intersecting a generally arcuate surface  172  and further intersecting a second surface, such as a vertical surface  174 . Each coupler may also terminate in a distal surface  175 . The vertical surface  174  is a distal surface to a flange element  176 . Each female coupler  127  and  128  defines a bore  178  extending between the lateral surface  170  and the arcuate surface  172 . Each male coupler  150  and  152  includes a male extension  180  extending from the lateral surface  170 . The male extension  180  is dimensioned to fit snugly within the bore  178 . In some embodiments, a fastener, such as a cotter pin (not shown), is extended through a bore (not shown) in the male extension  180  to retain the male extension  180  within the bore  178 . The lateral surface  170  may be dimensioned, and the male extension  180  disposed, such that joined female couplers  127  and  128  and male couplers  150  and  152  pivot about a longitudinal axis  182  of the male extension  180 . In other embodiments, the lateral surface  170  is dimensioned and the male extension  180  is disposed such that the joined female couplers  127  and  128  and male couplers  150  and  152  are substantially rigid because the distal surfaces  175  of the present male couplers abut the vertical surfaces  174  when the present couplers are joined. 
   A suitable embodiment of the present leg rest assembly and main frame has been made from Schedule 40½ inch pipe. The main frame cap cylindrical portion  156  may be constructed from 2 inch diameter, 14 gauge tubing and the locking tubes  110  may be made from 1 in. diameter, 14 gauge tubing. Various steel alloys have been used for the tubing in the foregoing elements. However, a person of ordinary skill in the art will recognize that several other materials may be suitable for other embodiments. Suitable synthetic resins may be identified by persons of ordinary skill in the art without undue experimentation from “Handbook of Plastics, Elastomers, and Composites, Third Addition,” Charles A. Harper Editor in Chief, McGraw-Hill, New York (1996), hereby incorporated by reference. 
   The present exerciser may be assembled by sliding the foam pads  122  past the second or third member  118  or  120  and spacing the foam pads  122  generally equidistantly on the first member  116 . Each of the second and third members  118  and  120  may then be extended through one of the locking tubes  110  so as to expose the female couplers  127  and  128 . The female couplers  127  and  128  are then joined to the male couplers  150  and  152  by disposing the male extensions  180  of one of the male couplers  150  and  152  through the bores  178  of the female couplers  127  and  128 . In one embodiment, the leg rest assembly  104  and the main frame  106  may then be pivoted when the present male and female couplers are joined as described supra. When in the folded position, the present exerciser  100  may be unfolded and secured in an unfolded, locked position by sliding the locking tubes  110  over the joints formed by joined female and male couplers  127 – 128  and  150 – 152 . When the locking tubes  110  are in position, the weight  112  is mounted on the cap  134  and secured in place by the spring collar  110  ( FIGS. 5   a – 5   c ). The weight  112  may be a plate weight commonly available for barbells or the like. The foregoing embodiment may be folded by removing the weight  112  from the cap  134 , sliding the locking tubes  110  toward the pads  122  thereby exposing the joints formed by joining the present female and male couplers, and pivoting the leg rest assembly  104  toward the main frame  106 . 
   In use and referring to  FIGS. 5   a – 5   d , a person advantageously utilizes the present exerciser to strengthen the person&#39;s abdominal muscles. The present exerciser is assembled or unfolded and secured as described supra. The weight  112  may weigh from 10 to 25 pounds. The amount of weight, however, is determined by the desire and level of conditioning of the person. The present exerciser is then placed ideally on a non-slippery surface, such as a carpet or mat. 
   The person then lies in a supine position with the person&#39;s back on the floor and the person&#39;s calves atop the pads  122  ( FIG. 5   a ). The person then forces their calves against the pads until their feet contact the floor, thereby raising the weight from a contacting position with the floor, e.g., the heels and balls of the person&#39;s feet are pressed against, or contacting, the floor ( FIG. 5   b ). At this point, the person&#39;s knees may be bent at a 90 degree angle (the person&#39;s calves are generally orthogonal to the person&#39;s thighs) and the pads  122  are contacting, or pressing against, the person&#39;s calves, e.g., about halfway between the person&#39;s feet and knees. At this point the person is in a proper position to begin exercising. The person then begins to tighten the muscles in the person&#39;s buttocks (gluteals), ideally slowly and without jerking movements. Simultaneously with tightening the buttock muscles, the person constricts the person&#39;s abdominal muscles, thereby performing a partial sit-up (or crunch) ( FIGS. 5   c  and  5   d ). Ideally, the person should require at least two seconds to perform this exercise. The exercise is properly performed keeping the person&#39;s feet flat on the floor and without dragging the present exerciser or the person&#39;s body across the floor. After the partial sit-up or crunch has been performed, the person slowly relaxes until the person&#39;s head is resting on the floor ( FIG. 5   a ) to complete an exercise replication. It may be desirable for the person to rest a brief time before performing another replication. 
   The present exerciser is advantageously effective in exercising a person&#39;s abdominal muscles because the present exerciser prevents the person&#39;s hip flexors from aiding in the sit-up protocol. To this end, the present exerciser applies an upward force to the person&#39;s calves and, thereby, eliminates the anchor point necessary for hip flexors to function. Stated otherwise, exerting an upward force on the person&#39;s calves during this exercise totally eliminates any possible anchor point for the person&#39;s hip flexors. Totally eliminating any possible anchor point for the person&#39;s hip flexors prevents the hip flexors from aiding the person&#39;s abdominal muscles during exercise and forces the person&#39;s abdominal muscles to perform the exercise in isolation. Moreover, if the person attempts to use the person&#39;s hip flexors by pulling the person&#39;s knees toward the person&#39;s chest, the present device is pulled toward the exerciser, thereby indicating that the person is exercising improperly. The present exerciser further enhances the exercise experience by forcing the person&#39;s gluteal muscles to contract when maintaining the present exerciser in the preferred position. Thus, another indication that the person is performing the exercise improperly is in response to the person relaxing the person&#39;s gluteal muscles, wherein the weight lifts the person&#39;s feet from the floor. 
   Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather the scope of the invention is to be determined by the appended claims and their equivalents.