1 An exercise apparatus FIELD OF THE INVENTION The present invention relates to an exercise apparatus and, in particular, an apparatus for assisting a user in performing various exercises including abdominal exercises without 5 obstructing the user's spine and coccyx. The present invention is useful in preventing the onset or aggravation of coccydynia in a user. BACKGROUND OF THE INVENTION Personal exercise is becoming an increasingly popular pastime for many people. In particular abdominal exercise is seen by many people as a path to a healthy and beautiful body. 0 The most popular form of abdominal exercise is abdominal curl, also known simply as a sit-up. Traditionally an abdominal curl has been performed on the floor without any equipment. In recent times various forms of apparatus have been introduced to enhance abdominal exercise ranging from a simple exercise ball to elaborate frames and platforms. In performing an abdominal curl a user will typically begin in a supine position, flex their 5 abdominal muscles and finish in an upright sitting position. During this movement a user's spine and coccyx will be in continuous contact with a supporting surface, whether it be the floor or the seat of an exercise apparatus. As the abdomen flexes, the users spine and coccyx will move across the supporting surface and be subjected to varying amounts of pressure. This varying pressure may lead to the onset or aggravation of coccydynia and other related injuries. 20 It is therefore an object of the present invention to overcome at least some of the aforementioned problems or to provide the public with a useful alternative. It is a further object of the present invention to provide an apparatus that will allow a user to perform seated exercises without their spine and coccyx being obstructed, thus preventing the potential onset or aggravation of coccydynia and other related injuries. 25 It is a still further object of the invention to provide a light weight and compact exercise apparatus that can be easily transported and stored. SUMMARY OF THE INVENTION Therefore, in a first form of the invention there is provided an exercise apparatus characterised by an elongate base structure upon which a user is adapted to sit, said base 30 including a clearance for a user's coccyx when performing exercises such as sit ups and leg 2 raises. Preferably the elongate base structure includes a front portion upon which the user is adapted to sit and a rear portion adapted to cushion the user's back, said clearance being located proximate said front portion. 5 In preference said base structure includes a substantially flat surface on which a user is adapted to rest part of their body such as their buttox or lower back, and said clearance is formed by a convex channel extending substantially centrally along said flat surface, said user adapted to align their coccyx with said convex channel when performing an exercise. Preferably said front portion is higher than said rear portion. 0 In preference said apparatus includes a gripping frame including two side longitudinal elements and a front end element, said gripping frame including at least one elevated gripping section disposed forwards of said base structure. In preference said gripping frame is removably attachable to said base structure. Alternatively said gripping frame is integral with said base structure. 5 In preference said gripping frame side elements includes opposed pairs of downward lugs positioned to define two elevated gripping sections on sides of the user and one elevated end gripping section. In preference said end gripping section is sized to accommodate and provide restraint to a user's feet when performing a sit up. 20 Preferably said base includes cushions to provide comfort to the user. In preference said cushions are affixed to an upper surface of the base. Preferably said upper surface includes pockets for accommodating the cushions. Alternatively said cushions are pivotable about a pivot axis extending transversely through said base. 25 Preferably said cushions are pivotable about pivot pins. In preference said cushions are pivotable by their own structural configuration and placement on said base. Preferably said gripping sections of said frame include grip assisting means. Preferably said base structure is constructed from roto-molded polypropylene.
3 In a further form of the invention there is proposed an exercise apparatus for assisting a user in performing sit ups, leg raises, bicycle kicks and other like exercises, said exercise apparatus characterised by: a moulded longitudinal body including a base above which said user is adapted to rest a body 5 part such as their buttox or lower back when performing said exercise, and a gripping frame disposed forwards of said base, said gripping frame providing at least one elevated section for a user to hold onto for support, or alternatively to restrain a body part during an exercise, said base including a channel which is appropriately positioned to provide a clearance for the user's spine and coccyx when performing said exercise. 0 In preference said body is made of lightweight moulded plastic material and includes a slim-line design. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the 5 description, serve to explain the advantages and principles of the invention. In the drawings: Figure 1 illustrates a top perspective view of an exercise apparatus in accordance with a first embodiment of the present invention; Figure 2 illustrates a side view of the exercise apparatus of Figure 1 whilst in use; Figure 3 illustrates an underside, exploded perspective view of the exercise .0 apparatus of Figure 1; Figures 4a-4b illustrate respectively an end view of the apparatus and an end view of the apparatus whilst in use; Figure 5 illustrates a top perspective view of an exercise apparatus in accordance with a second embodiment of the present invention; 25 Figure 6 illustrates a side view of the exercise apparatus of Figure 5 whilst in use; Figure 7 illustrates a top view of an exercise apparatus in accordance with a third embodiment of the present invention; Figure 8 illustrates a side view of the exercise apparatus of Figure 7; Figure 9 illustrates an underside view of the exercise apparatus of Figure 7; 30 Figure 10 illustrates a front view of the exercise apparatus of Figure 7; 4 Figure 11 illustrates a rear view of the exercise apparatus of Figure 7; and Figure 12 illustrates a top perspective view of the exercise apparatus of Figure 7. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanying drawings. 5 Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Figures 1-4 illustrate an exercise apparatus 10a according to a first embodiment of the 0 invention, Figures 5-6 illustrate an exercise apparatus 10b according to a second embodiment, and Figures 7-12 illustrate an exercise apparatus 10c according to a third and preferred embodiment of the invention. Turning firstly to Figures 1-4, there is an exercise apparatus 10a comprising a base 12 of substantially rectangular form having a flat bottom surface 14 for placement of the base 12 on 5 the ground, and an upper surface 16 defining a front portion 18 adapted for sitting on, and a rear portion 20 adapted to cushion a user's 22 back during a sit-up motion. The base 12 is preferably constructed of a roto-moulded propylene material. The upper surface 16 is angled such that the front portion 18 is higher than the rear portion 20, and includes upward walls 23 on either side. Two elongate cushions or pads 24 and .0 26 are affixed upon the base 12 and, in particular, in respective shallow pockets 28 and 30 which are preferably moulded into the upper surface 16. The apparatus 10a further includes a tube frame 32 which is also of a substantially rectangular form. The bottom surface 14 of the base 12 is substantially flat, however, it does include a number of rib formations 34 for improved strength and overall weight, and also to use 25 less material during manufacture. The bottom surface 14 further includes a channel 36 at the front of the base 12 shaped and dimensioned to accommodate an end of the tube frame 22. This can be seen most clearly in Figure 3. In preference, the tube frame is available in two sections 38 and 40, section 38 being adapted to be received in channel 36 and secured to the base 12 using screws 42, and section 40 30 adapted to be attached to section 38. In the embodiment shown, the two sections 38 and 40 are attachable by way of a telescopic tube frame arrangement as is known in the art. This 5 arrangement allows for partial disassembly of the apparatus 10a, such that it occupies minimal volume for transportation and storage. When the tube frame 32 is assembled and attached to the base 12, it too contacts the ground along its length to provide stability to the apparatus 10a. The tube frame 32 however does 5 include elevated portions, the first portion 44 being approximately halfway along the length of the frame for providing the frame with handles for a user to grasp during an exercise, and portion 46 being the free end of the frame 32 allowing passing of a user's feet there beneath. The skilled addressee would realize that this elevated portion 46 of the frame 32 restrains the user's feet during an exercise. There is also a sleeve 48 provided at the end for cushioning the user's feet. 0 Referring to the upper surface 16 of the base 12 once again, and an important feature of the present invention, there is a convex channel 50 between the cushions 24 and 26 extending from the front of the base 12 to a position just before the rear. The convex channel 50 provides a clearance 52 for a user's spine and coccyx whilst they are seated on the apparatus 10a performing an exercise. This can be seen most clearly in Figure 4b. A person skilled in the art 5 would realize that in having a clearance 52 in this area of the apparatus 10a, the onset or aggravation of coccydynia in a user 22 will be greatly reduced or prevented, as the obstructive surface has been removed. An exercise apparatus 10b according to a second embodiment of the invention is shown in Figures 5-6. Like parts between the apparatus 10a and 10b are referred to using like reference 0 numerals. The difference between the two embodiments resides in the configuration of the cushions. The cushions 54 and 56 of apparatus 10b are more rigid in structure and not adapted to be affixed to the top surface 16 but rather placed in an almost pivotal configuration above the body 12, whereby the axis of pivot extends transversely through the body 12. The range of 25 movement of the pads 54 and 56 can be seen most clearly in Figure 6. The pads 54 and 56 could be made to move in this way either through use of one or more pivoting rods (not shown), or by way of their own slightly flexible structure which would allow this range of motion. It is envisaged that the pads configured in this way will provide not only increased cushioning during exercise, but also increased reinforcement to a user's back whilst performing sit-ups. 30 Figures 7-12 illustrate various views of an exercise apparatus 10c according to a third and preferred embodiment of the invention. The apparatus 10c is similar in its functional aspects to the apparatus 10a of the first embodiment, except it includes a more slim-line design and is of 6 single-piece construction whereby the base and frame sections are integrally formed. The base and frame are preferably constructed of a lightweight yet durable plastic material. Thus, no assembly is required, and because of the design and weight of the apparatus, it can be easily transported and stored away. 5 The body 58 of the apparatus 1Oc includes a longitudinal, substantially rectangular base section 60 having a flat bottom surface 62 and an upper surface 64. Again, the upper surface includes a higher front than rear, and includes walls 70 on either side, although these do not rise as high as say walls 23 of the first embodiment, resulting in a more slim-line design. Instead, the walls 70 extend longitudinally forwards and beyond the base section 60 to also form side 0 portions of an integral frame section 72 of the apparatus. Each side wall extension further includes two integral downward lugs, the first pair of opposed lugs 74 being positioned adjacent the front end of the frame and the second pair of opposed lugs 76 being positioned adjacent the forward end of the base section 60. The lugs thereby elevate sections of the frame so as to provide means for gripping the frame during exercise. In particular, the gripping sections include 5 the sections of frame 78 and 80 between the two lugs on either side of the frame, and the transverse end section 82 of the frame extending between the two end lugs 74. Again, bottom surface 62 of the base is substantially flat, however, it does include a number of rib formations 84 as well as side ridges 86 for improved strength and overall weight, and also to use less material during manufacture. There are two elongate cushions or pads 88 are 0 affixed upon the base 12, and this may be achieved by any suitable means, including moulding accommodating pockets into the upper surface as described earlier. The apparatus 1 Oc also includes the convex channel 90 between the pads which provides a clearance 92 for a user's spine and coccyx whilst they are seated on the apparatus 1Oc performing an exercise. The skilled addressee would realise that, for example, when performing 25 a sit-up, a user will sit on the cushions so that his or her spine and coccyx aligns inside the clearance 92, and will place their feet beneath the end gripping member 82. When performing other exercises such as leg raises and bicycle kicks, the user will be orientated in the opposite direction such that they are now seated towards the rear of the apparatus, and so that he or she can either grab onto the end gripping section 82 with both hands behind their head, or the side 30 gripping sections 78 and 80. A user could also perform say push ups using the apparatus 10c by gripping and pushing up on the side gripping sections 78 and 80. The present invention therefore provides an improved exercise apparatus and, in 7 particular, a sit-up apparatus which is compact, light weight, easily transportable, easily stored, and which is configured in a unique manner to reduce the risk of back injury during use. It is to be understood that although the present invention is directed specifically towards an ab-exercise machine, the concept of having a scalloped surface could equally well be applied 5 to other exercise equipment involving contact with a user's coccyx, such as any exercise bench for example. Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures 0 may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is 5 used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.