Patent Publication Number: US-10765594-B2

Title: Massage foam roller apparatus and system

Description:
This application claims priority to my U.S. Provisional Patent Application No. 61/968,344 filed on Mar. 20, 2014 and entitled “Improved Massage Foam Roller Apparatus and System”. The entire content of the application is expressly incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to therapeutic massage apparatus and more particularly to an improved therapeutic “foam” massage roller apparatus and system for use by athletes, chiropractors, personal trainers, massage therapists and physical therapists to relax various body muscles. 
     The therapeutic activity known as foam rolling is a self-myofascial release (SMR) technique that is used to relax overactive or tight muscles and is a form of stretching that utilizes the concept of autogenic inhibition to improve soft tissue extensibility, thus relaxing the muscle(s) and allowing the activation of the antagonist muscle(s). The technique can be effective for many muscles, including the gastrocnemius, latissimus dorsi, piriformis, adductors, quadriceps, hamstrings, hip flexors, thoracic spine (trapezius and rhomboids), and tensor fasciae latae (TFL) muscles, and is accomplished by rolling a resilient foam roller under each muscle group until a tender area is found, and then maintaining pressure on the tender areas (known as trigger points) for 30 to 60 seconds. While there is currently a lack of research materials relating to the actual use of foam rollers, it is widely recognized that the use of such rollers have the same effects as deep-tissue massage, of which there has been considerable research on the effects of such massage on the body, much of which can also be carried over to rolling. 
     The apparatus normally used for rolling usually consists of a foam cylinder or foam covered hollow core of various sizes; commonly twelve or more inches long and approximately six or so inches in diameter. However, longer foam rolls up to approximately 36 inches in length may be used for rolling over certain muscles in the back. A variety of foam roller materials (including ethylene vinyl acetate (EVA) and polyurethanes) and densities have been used, often denoted by the color of the roller. 
     Those new to foam rolling, or those who have particularly tight muscles or severe trigger points, often start with a softer foam roll and then move on to other roller configurations particularly suited to their therapeutic need. By performing with certain roller types and techniques, one can improve flexibility, function, performance, and reduce injuries by using his/her own body weight to roll on the round foam roll, massaging away restrictions to normal soft-tissue extensibility thereby improving recovery time. 
     Many types of roller devices are currently in use. However, the surface types and rigidity of such devices are not easily modifiable or changeable, and it is often the case that several different types of roller devices must be available to address multiple muscle-type therapy needs. In addition, the user of a foam roller in a gym or other public environment often has to carry with him/her sundry items like watches, keys, wallets or gym keys, etc., and has no secure place to leave them during use of the roller or rollers. Moreover, currently available rollers are usually awkward to carry thus necessitating the addition use (and expense) of a carry bag or clumsy leash or strap. In addition, there is no place to carry water and/or various drinking fluids, etc. 
     Currently available rollers are limited in surface patterns and density because not all patterns offer smooth rolling. Patterns with wide gaps are not possible because the roller will get stuck and cause the user to strain to move the roller back and forth. Rollers with patterns and heavy density suffer from the same challenges. 
     It is therefore an objective of the present invention to provide an improved foam roller apparatus the design and configuration of which is based on sound medical/scientific concepts. 
     Another objective, of the present invention is to provide a foam roller apparatus that can be conveniently reconfigured to address particular therapeutic needs or concerns. 
     Still another objective of the present invention is to provide a foam roller system and apparatus that can be selectively configured to accommodate a wide range of users from beginner to advanced user. 
     A further objective is to provide smoother rolling on a patterned and/or high density surface by designing the roller with more height (larger diameter) at the end caps than in the roller body, thereby distributing the user&#39;s weight to the end caps and providing smooth rolling no matter what pattern or density is utilized. 
     Another objective is to offer improved therapeutic surfaces with novel patterns that are made possible due to the novel end cap design. These are shapes that would cause the roller to stick with traditional roller designs, where weight is not distributed on the end caps. 
     Yet another objective of the present invention is to provide a foam roller apparatus having easily interchangeable parts and features that can be mixed and matched to accommodate the particular needs and convenience of a wide range of users. 
     Briefly, an embodiment of the present invention includes a roller body comprised of at least two replaceable resilient therapeutic massage pads and an associated pad substrate adapted to be mounted on a rigid, generally tubular core element, and a pair of end caps provided to lockingly mate with and enclose the ends of the core. The interior space of the core element may be used as a storage chamber for storing sundry items. In addition, a detachable carry strap may be affixed to the end caps to accommodate transport of the device. 
     Another embodiment of the present invention includes a roller unit comprised of at least two replaceable resilient therapeutic massage pads mounted on corresponding substantially rigid pad substrates adapted to mate together to form a generally tubular roller body held together by a pair of end caps provided to both retain the component parts together and close the ends of the body. Preferably, the end caps are circular and of somewhat larger diameter than the roller body so that the weight of the user is transferred, or distributed, to the end caps such that the unit rolls smoothly on its supporting surface independent of the pattern or density of the massage pads. 
     Embodiments of the present invention are preferably of a snap-together design allowing ease of assembly as well as user convenience in change of massage surface configuration. 
     An important advantage of the present invention is that it provides a roller unit having replaceable foam cover pads which are readily interchangeable with other cover pads having different therapeutic massage characteristics. 
     Another advantage of the present invention is that it allows the use of different types of pads made of different materials having different degrees of resiliency or hardness and/or surface contours. 
     Still another advantage of the present invention is that it provides a roller assembly that can be used with or without the included end caps. 
     Yet another advantage of the present invention is that it provides a storage facility for storing other items the user might have in his/her possession at the time and place of use of the roller. 
     A still further advantage of the present invention is that it allows the user to select whether he/she wants the rolling engagement with the supporting surface to be influenced by or independent of the therapeutic pad characteristics. 
     These and other objectives and advantages of the present invention will no doubt become apparent to those skilled in the art after a reading of the following detailed disclosure of the various alternative embodiments illustrated in the several figures of the drawing. 
    
    
     
       IN THE DRAWING 
         FIG. 1  is a perspective view generally illustrating an embodiment of an improved massage roller in accordance with the present invention; 
         FIG. 2  is an exploded view illustrating the several components of the embodiment shown in  FIG. 1 ; 
         FIG. 3  is a perspective view showing functional details of the core component illustrated in  FIG. 2 ; 
         FIG. 4  is a perspective view showing the spring clip component illustrated in  FIG. 2 ; 
         FIG. 5  is a cross-sectional view taken along the plane of the arrows  5 - 5  of  FIG. 3  and illustrating the installation and operation of the spring clip shown in  FIG. 4  as it is installed on the core depicted in  FIGS. 2 and 3 ; 
         FIG. 6  is a perspective view showing functional features of the underside of the cover pad substrate component illustrated in  FIG. 2 ; 
         FIG. 6A  is a transverse cross-sectional view of the cover pad substrate component taken along the plane of the arrows  6 A in  FIG. 6 ; 
         FIG. 6B  is a cross-sectional view as in  FIG. 6A  showing the cover pad substrate component and its relationship to the core shown in  FIGS. 2 and 3 ; 
         FIG. 7  is a partially broken side view illustrating installation of the assembled cover pad/substrate onto the core shown in  FIGS. 2 and 3 ; 
         FIG. 8  is a broken partial cross-sectional view illustrating operation of the spring clip of  FIG. 4  in centering the assembled cover pad/substrate onto the core depicted in  FIG. 7 ; 
         FIG. 9  is a partially broken side view illustrating an assembled massage roller in accordance with the present invention before the end caps shown in  FIGS. 1 and 2  are attached; 
         FIG. 10  is a perspective view showing structural and functional details of the end caps and associated collars depicted in  FIGS. 1 and 2 ; 
         FIG. 11  is partially broken cross-sectional view showing a cap assembly mounted to one end of an assembled roller in accordance with the present invention; 
         FIG. 11A  is a broken plan view showing details of the end cap locking tab, detent and core slot generally illustrated in  FIG. 11 ; 
         FIGS. 12A and 12B  are simplified partially broken cross-sectional views looking in the direction of arrows  12 A- 12 A in  FIG. 11  and illustrating the locking engagement of an end cap to the roller core; 
         FIG. 13  is an exploded perspective view showing an embodiment of a container adapted to be attached to an end cap and inserted into the roller upon attachment of the end cap to the roller; 
         FIG. 14  is a perspective view illustrating attachment of the container of  FIG. 13  to the inside of an end cap; 
         FIG. 15  is a partially broken cross-sectional view further illustrating attachment of the container of  FIGS. 13 and 14  to the inside of an end cap; 
         FIGS. 16 and 17  are side views illustrating rollers having alternative pad surfaces in accordance with other embodiments of the present invention. 
         FIG. 18  is a transverse cross-sectional view illustrating an alternative method of attachment of the cover pad/substrate subassemblies or modules in accordance with the present invention; and 
         FIG. 19  is a transverse cross-sectional view illustrating an alternative embodiment of the present invention in which more than two cover pad/substrate subassemblies are mounted on an alternatively configured core. 
         FIG. 20  is a perspective view generally illustrating an alternative embodiment of an improved massage roller and depicting at opposite ends thereof alternative end cap configurations in accordance with the present invention; 
         FIG. 21  is an exploded perspective view illustrating several component parts of the embodiment shown in  FIG. 20 ; 
         FIG. 22  is a broken longitudinal cross-sectional view taken along the plane of the arrows  22 - 22  of  FIG. 20  and illustrating internal details of the embodiment; 
         FIG. 22A  is a transverse cross section of  FIG. 22  taken along the line  22 A- 22 A; 
         FIG. 23  is an exploded perspective view showing mating details of the cover pad/substrate subassemblies of the embodiment of  FIG. 20 ; 
         FIG. 24  is an exploded perspective view showing details of the mating substrate parts of the embodiment of  FIG. 20 ; 
         FIG. 25  is an exploded perspective view showing details of the threaded end of the substrate parts illustrated in  FIG. 24 ; 
         FIG. 26  is an exploded perspective view showing details of the unthreaded end of the substrate parts illustrated in  FIG. 24 ; 
         FIG. 27A  is an exploded perspective view showing details from one side of the unthreaded end cap of the embodiment illustrated in  FIG. 20 ; 
         FIG. 27B  is an exploded perspective view showing details from the opposite side of the unthreaded end cap of the embodiment illustrated in  FIG. 20 ; 
         FIG. 27C  is an exploded perspective view showing details from the opposite side of the unthreaded end cap of the embodiment illustrated in  FIG. 20 ; 
         FIG. 27 d    is a partial cross section view showing details relating to the end cap latching function of the embodiment illustrated in  FIG. 20 ; 
         FIG. 28A  is a perspective view showing the locking mechanism of the assembled unthreaded end cap of the embodiment illustrated in  FIG. 20  in an unlocked configuration; 
         FIG. 28B  is a perspective view showing the locking mechanism of the assembled unthreaded end cap of the embodiment illustrated in  FIG. 20  rotated into a locked configuration; 
         FIGS. 29A and 29B  respectively show opposite sides of a threaded end cap of the embodiment illustrated in  FIG. 20 ; 
         FIG. 30  is a perspective view generally illustrating another alternative embodiment of an improved massage roller in accordance with the present invention; 
         FIG. 31  is a longitudinal cross-sectional view taken along the plane of the arrows  31 - 31  of the embodiment of  FIG. 30  and illustrating internal details thereof; 
         FIG. 32  is a partial perspective view showing various internal details of the embodiment of  FIG. 30 ; 
         FIG. 33  is a partial transverse cross-sectional view taken along the arrows  33 - 33  of  FIG. 32  and illustrating internal details thereof; 
         FIG. 34  is an exploded perspective view showing the several component parts of an end cap of the type illustrated in  FIG. 32 ; and 
         FIG. 35  is an exploded perspective view showing the method of attachment of an end cap of the type illustrated in  FIG. 32 . 
         FIG. 36  is partial perspective view showing an end of the roller body of  FIG. 30  before attachment of an end cap of the type illustrated in  FIG. 35 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring to  FIG. 1  of the drawing, an embodiment of an improved massage roller in accordance with the present invention is illustrated at  10  and includes a roller body  12  comprised of, inter alia, a pair of replaceable resilient therapeutic massage pads  14  and  16  made of EVA or polyurethane or the like, and a pair of substantially rigid, injected molded PVC or nylon end caps  18  and  20 . Note that as will be further disclosed below, the end caps  18  and  20  include a substantially rigid cap part  22  adapted to mate with the body  12 , and a resilient collar  24  also made of EVA or polyurethane or the like. In addition, the end caps may include a recessed opening, passageway and keeper  26  to which an accessory carry strap (not shown) may be attached for accommodating transport of the roller device. 
     Turning now to  FIG. 2 , which is an exploded perspective view of the subject massage roller  10 , the body  12  includes a rigid core  28 , a pair of substrates  30  and  32 , and a pair of resilient cover pads  34  and  36 . In addition, the core  28  has attached thereto a pair of spring clips  38  and  40  to be described below. As will also be further explained below, the cover pads  34  and  36  are respectively fastened to the substrates  30  and  32  by a suitable fastening means such as glue, mastic or even a mechanical fastener such as Velcro or the like. 
     As depicted, the core  28  is preferably generally cylindrical and tubular in configuration, but has two diametrically opposed, longitudinally extending flats  42  and  44  respectively formed in its top and bottom surfaces. Each flat is advantageously provided with a recessed opening and slot  39  for receiving and mating with a spring clip  38 / 40 . Core  28  also has two diametrically opposed slots or channels  46  and  47  respectively extending longitudinally along its sides, and four orthogonally positioned and transversely extending slots  48  formed therein proximate each extremity. Core  28  is preferably an extruded part made of PVC (polyvinylchloride), or similar material, with the transverse slots  48  made by sawing, punching or stamping. The thickness of the extrusion is chosen to be suitable for the application. 
     As will be further described below in more detail, end caps  20  and  22  include an annular perimeter  50  for receiving and supporting the annularly configured resilient collar  24  which is adhered thereto by a suitable glue or mastic, and a cylindrical, rearwardly extending neck portion  52  for mating with the openings at the ends of core  28 . In addition, the necks  52  are provided with four radially extending tabs  54  for lockingly engaging the slots  48  from inside core  28 . The outwardly facing surfaces of caps  20  and  22  have recessed finger openings  56  provided therein for receiving a user&#39;s fingers and defining a “handle”  58  and enabling the user to conveniently insert the neck  52  into an end of core  28  and rotate the cap to lockingly engage the tabs  54  with the slots  48 . 
     Shown below the exploded assembly is a an optional strap  60  having suitable snap fasteners  62  and  63  affixed to each end to permit attachment of the strap to the keepers crossing the openings  26  in the end caps  20 / 22  installed at each end of the assembled roller to provide ease of transport thereof. Alternatively, a carabiner or other suitable strap fastener may be used. 
     Referring to  FIGS. 3-5 , and as depicted in  FIG. 3 , and shown in greater detail in the cross-section taken according to the arrows  5 - 5  and depicted in  FIG. 5 , core  28  includes a pair of receptacles  39  for receiving, mating with and accommodating the spring clips  38 / 40 . In  FIG. 4 , additional details regarding the spring clips  38  and  40  and their relationship to core  28  are discussed, as well as their specific relationships to core  28 . As depicted in inverted form in this figure, it will be understood that the clips  38 / 40  are preformed elements made from elongated strips of 28-gauge spring steel, and include at one end thereof, a transversely extending hook-like structure  70  formed upwardly to one side of the strip, and a detent-forming hook-like structure  72  formed to extend downwardly at the other end. Intermediate the ends, an upwardly extending tab  74  is formed. In the illustrated embodiment, the receptacles  39  include a rectangular spring relief opening  80  and a transversely oriented slot  82 , the two being separated by a recessed surface area  84 . 
     As is apparent from the showing in  FIG. 5 , which is a cross-section taken along the line  5 - 5  in  FIG. 3 , the spring clips can be mounted to the core  28  by inserting the hook  70  into the slot  82  and then rotating and pulling the clip leftwardly into the recessed surface area  84  until the tab  74  enters the opening  80  and serves as a retainer for the clip. With the clip so installed, the portion thereof extending over the recessed surface area  84  is normally flush with the core surface, and the portion  73  thereof extending over the opening  80  and terminating in the hook  72  provides a resilient, upwardly (outwardly relative to the outer surface of the core) extending detent  72  which can be biased downwardly in cantilever fashion into the opening  80  as indicated by the dashed lines  73 . 
     In  FIG. 6 , the reverse, or internal, sides  85  of the cover substrates  30  and  32  depicted in  FIG. 2  is shown to include inwardly turned lateral edges  86  and  87  which, as further discussed below, will respectively engage the channels  46 / 47  ( FIG. 3 ) and secure the substrates to core  28 . This figure additionally reveals several elongated ridges or ribs  88  formed on the inner substrate surface  89  and running the length thereof. Also shown are notches  83  formed mid-length along ribs  88  which, as will be disclosed below, will be engaged by the detents  72  ( FIG. 5 ) to longitudinally lock the substrates  30 / 32  in position on core  28 . 
     As is perhaps be better shown in the transverse cross-section  6 A- 6 A taken along the plane evidenced by the arrows  6 A shown in  FIG. 6 , the rib-tops  90  are disposed co-planar with and adapted to ride on the external surfaces of the core flats  42 / 44 , as further illustrated in the lower part of the cross-section of  FIG. 6B , when the substrate is installed on the core  28 . Note in this figure the inwardly positioned extremity of the hook  70 , previously described and shown in  FIG. 5 . In this figure the extension of the detent  72  into the rib notches  83  is shown. 
     Turning now to  FIGS. 7-9 , installation of the cover pad/substrate subassemblies or modules  14 / 16  to the core  28  is illustrated. As shown in the partially broken side view of  FIG. 7 , after the cover pad  34  is attached to the substrate  30 , and one end of the subassembly is positioned at an end of the core  28  with its internally extending side edges  86 / 87  aligned with the side grooves  46 / 47 , the top surfaces  90  ( FIG. 6A ) will be aligned with the outer surface of the flat  42 , and the unit  14  can be slid along the length of core  28  as suggested by the arrow  7 A. As the leading edge of the subassembly reaches the detent  72  at the middle of core  28 , the intersection of the ribs  88  with the detent  72  will cause the detent and cantilevered portion of the spring clip  38  to be resiliently depressed into the opening  80 , as illustrated by the dashed lines  73  in the cross-section of  FIG. 8 . The rightward movement of the subassembly can thus continue until it is stopped at the end of the core by the detent  72  engaging the notches  83  in the ribs  88 . The lower pad subassembly  16  is then similarly installed on core  28 . 
     In  FIG. 9 , the completed assembly of the replaceable massage pad units  14  and  16  to the core  28  is illustrated in a side view with the subassembly  16  broken to show the respective relationships of pad  36  to substrate  32  to core  28 . With the pads thus assembled to core  28 , the subject roller assembly is not yet complete but could be used without the end caps. However, to complete the preferred embodiment of the present invention all that is needed is to install the two end caps. 
       FIG. 10  is a partially broken perspective view illustrating the inside features of an injection molded end version of the end cap  18  previously shown in  FIG. 2 . As depicted, the cap includes a tapered outer perimeter portion  92  and an annular portion  50  configured to receive the resilient collar  24 . In addition, the cap includes an inwardly extending neck portion  52  adapted for insertion into the inner bore of the core  28  described above. In one embodiment the collar  24  is suitably affixed with glue, or the like, to the surfaces  50  and  92 . The neck portion  52  is configured to have four outwardly extending retainer tabs  54  orthogonally positioned about the neck portion for lockingly engaging the core slots  48 . As will be further described below, the tabs are made somewhat flexible in the axial direction of the cap. On the inner surfaces  53  of the neck portion, inwardly extending partial annular ribs  55  are formed to serve as retainers for a container device, or the like, nested within the cap as will be described below. 
       FIG. 11  is a partially broken cross-sectional view further clarifying certain end cap details and cap-to-roller body relationships. In this figure, a generalized cross-sectional view of end cap  18  is shown with the cap mated to an end of the core  28  after the pad modules  14  and  16  have been installed on the core. As depicted, the neck  52  has been inserted into the end of core  28 , and has been rotated into its locked position relative to the core, and with its locking tabs  54  in engagement with the core slots  48 . Note that, in the middle of the figure. a portion of a locking tab  54  is visible through the slot  48 . At the top and bottom of the figure, two of the other three tabs  54  are shown in cross-section extending into the top and bottom slots  48 . In this figure, the interior surface  53  of neck  52  and portions of the article container retainer rib  55  are also shown. 
       FIG. 11A  is a broken plan view showing further details of the end cap locking tab  54  and core slot  48  generally illustrated in  FIG. 11 . As is more clearly illustrated in this figure, the right side of the slots  48  are bowed out to provide shallow locking recesses  49  for receiving locking detents  57  formed in the mid-portions of the retainer tabs  54 . Note that the cap retaining and locking tabs  54  are designed to be somewhat flexible so that upon engagement with the slots  48  they resiliently cam in the axial direction of the cap and then snap into a locking configuration as the detents  57  reach and mate with the recesses  49 . 
       FIGS. 12A and 12B  are simplified pseudo cross-sectional views further illustrating the end cap locking operation and relationships between the cap neck  52 , core  28 , substrate  30  and pad  34  components previously described. For simplicity, only the upper pad-substrate module  14  is shown mounted to the core  28 . Specifically, in  FIG. 12A , the cap mating and rotational disposition of the cap neck  52  is shown with its locking tabs rotated 45 degrees from a vertical/horizontal disposition in order to clear the side groove forming core deformations  94  and  96  upon insertion of the cap neck into the end of core  28 . 
     In  FIG. 12B , the angular rotation of the cap neck  52  and its retainer tabs  54  with respect to the groove forming portions  94  and  96  of the core  28  in order to lock the cap in place is shown, i.e., by rotating the cap 45 degrees in either direction, the distal ends/edges of the tabs  54  will be caused to pass into the slots  48  formed in core  28 . As mentioned above, the retaining function of the engagement of substrate edges  86  and  87  within the core side grooves  46  and  47  is depicted in  FIG. 11A . 
     As will be understood by those skilled in the art, the radial dimension of the end cap tabs  54  must be less than the primary inside diameter of the core  28  in order to allow the neck  52  to enter the ends of the core (with the cap rotationally positioned as depicted in  FIG. 12A ), but must be large enough to extend into the slots  48  in the core flats  42  and  44 , and the groove forming deformations  46  and  47  when the cap is rotated 45 degrees (as suggested by  FIG. 12B ), in order to lock the cap in position at the end of the core. 
     As alluded to above, the hollow inside of the core  28  may be used to store sundry items such as exercise clothing, car keys, locker keys, etc. In one embodiment, a cup shaped container  104  and cap  102 , such as that illustrated at  100  in  FIG. 13 , might be provided and attached to, or be carried by, one of the end caps  18 / 20 , as depicted in  FIG. 14  and the partially broken sectional view of  FIG. 15 . In this embodiment, the container  104  may have an outside diameter slightly smaller than the inside diameter of the cap neck  52  and be provided with an annular groove  106  near its base to effect a retaining engagement with an annular rib or set of partial annular ribs  51  molded inside the cap neck (see also the showing of such a rib-like retainer  51  in the cap  18  shown in  FIG. 10 ). In this embodiment the container would be press-fit into the cap and be removeably retained therein by the engagement of groove  106  with rib  51 . Alternatively, the container might be made more easily removable by the use of a suitable screw and thread arrangement. 
     Referring now to  FIGS. 16 and 17 , although the surfaces of the roller pad modules described above are shown as being smooth, alternative, less smooth, dimpled or ribbed pad surface configurations or the like adapted to achieve particular therapeutic results may also be used. For example, the surface may include molded spheres or hemispheres such as is illustrated in  FIG. 16 , or peaks, or annular or elongated ridges, or other suitable configurations. In addition, pads with different or unmatched surface configurations such as are illustrated in  FIG. 17  can be used. 
     As described above with respect to the preferred embodiment, in order to install the roller pads on a core, one would simply position one end of each pad-substrate module at an end of the core, align the inwardly turned side edges of the pad carrying substrate with the elongated core side grooves, and slide the subassemblies longitudinally along the core, passed the centrally disposed detent until the detent engages the notches formed in the ridges on the bottom surfaces of the substrates, at which time the subassemblies will be properly placed and retained in position by the detents until the end caps are installed. To remove the subassemblies from the core, the operation would simply be reversed allowing a new or different pad or pad set to be installed on the core. 
     An alternative embodiment might include the use of a more flexible substrate or substrate material that would allow mounting of the pad modules to the core by simply forcing each pad-module over the core, as suggested by the arrows X and Y in  FIG. 18 , until the inwardly extending substrate edges flex out and cam over the core surfaces, and snap into place in the core side grooves. In this case, the end caps might be relied on to maintain the pads in their longitudinal positions relative to the core. This is to say, without use of the centering spring clip. Alternatively, one might use one or more small magnets, Velcro strips, or other similar materials or devices to center the pad assemblies on the core. In this embodiment, in order to remove the pad modules from the core, one would remove one of the end caps and spread the substrate to disengage the side edges from the core grooves, and then lift the subassembly from the core, or if no centering device was used, simply slide the module off of the core. 
     In still another embodiment, and as illustrated in  FIG. 19 , a core  130  with three or more elongated side grooves  132  might be used to accommodate a corresponding plurality of pad-substrate modules  134  that could be mounted on and secured to the core  130  in a manner similar to the above described methods. In using this embodiment one could use a desired plurality of pad surface textures or degrees of softness (or hardness) to achieve a desired therapeutic result 
     In yet another embodiment other forms of detents (not shown), or slot configurations, might be used. Similarly, other substrate edge configurations might be provided for engaging the slots  48  or other slots provided in the core to laterally secure the cover pad modules in place on the core. 
     In  FIG. 20 , a further embodiment of the present invention is illustrated at  140  and includes a therapeutic roller device comprised of, inter alia, a pair of replaceable resilient therapeutic massage pad assemblies  141  and  142  mated together at a split line  143  similar to that described above, and a pair of end caps  144  and  146  that secure the assemblies together. Unlike the previously described embodiments, this embodiment includes no rigid core  28  as described above, includes parts that snap together, and a new type of end caps that are preferably slightly larger in outer diameter than the massage pad assemblies so that the user&#39;s body weight applied to the massage pads is transferred, or distributed, to the end caps. As a result of the new end cap designs, the pad assemblies are effectively separated from the floor, or other supporting platform, such that the surface characteristics of the pads do not adversely affect the smoothness of the roll as the user moves the device across the floor. 
     As will be further disclosed below, the end caps  144  and  146  are advantageously rigid in construction. In one embodiment, the rolling surface thereof is preferably over-molded or otherwise fitted with a relatively thin resilient coating of rubber or plastic. In another embodiment, the over-mold is of a less resilient material and is thicker in the radial dimension of the cap. 
     Although the end caps of this embodiment are usually of at least substantially the same configuration, in order to simplify this disclosure, and as illustrated in the exploded perspective view of  FIG. 21 , one end of the roller body is shown as having a threaded end  148  for receiving an internally threaded cap unit  144 , and the other end is shown in an unthreaded configuration  150  including a raised shoulder forming portion of substantially larger diameter than that of the substrate parts  152  and  156  ( FIG. 22 ). This channel shaped ( FIG. 21 ) part of the substrate assembly forms a structurally stout annulus for engagement with the thin walled cap  146 , and in combination therewith allows the cap to support user loads transferred thereto. As depicted in the cross section of  FIG. 22 , it will be noted that when engaged with the relatively thin walled cap  146 , the annulus  150  is received within and enveloped by the outer said band of the cap 
       FIG. 22 , which is a broken, longitudinal cross-section taken along the plane defined by the arrows  22 - 22  in  FIG. 20 , the roller body formed by the mated massage pad assemblies  141  and  142 , which are aligned and joined together at the split line  143 , is held together by the locking engagement of caps  144  and  146  to the respective ends of the body. 
     Assembly  141  is comprised of an elongated half-round substrate  152  having a preformed dimpled layer or shell of foam pad material  154  affixed thereto using well-known bonding techniques of the type described above. The substrate  152  is preferably a molded plastic part having connection facilitating features formed on each end as illustrated. 
     Assembly  142  is similarly comprised of an elongated half-round substrate  156  having a preformed layer or shell of foam pad material  158  affixed thereto. Either or both of the shells may be made of a material having a plain or specifically textured outer surface. The substrate  156  is, like substrate  152 , preferably a molded plastic part having the same connection facilitating features formed on each end as does substrate  152 . 
     As depicted in  FIGS. 23 and 24 , one side edge of each substrate includes a channel or groove  166  (or series of channel or groove segments) running from substantially one end of the edge to the other, and the other side edge of each substrate includes an upstanding rib (or series of rib segments) running the length thereof such that when the two substrates are mated together, the ribs enter and mate with the channels. 
     As also shown in  FIGS. 22A, 23 and 25 , an alignment pin  170  and socket  172  are respectively formed in the side edges of each end portion of the substrates two achieve and maintain axial alignment of the mated substrates. 
     As pointed out above, for purposes of illustration, and as also depicted in  FIGS. 21-25 , one end of each substrate is configured to have external threads  148  formed on an end portion thereof to collectively form, when the substrates are mated together, a threaded cylindrical surface adapted to be engaged by internal threads  160  formed in an end cap  144 . The purpose of such engagement is to capture that end of the mated massage pad assemblies  141  and  142  and to hold them together to maintain the integrity of the roller body during use of the device. 
     As also shown in  FIGS. 22-24 and 26 , the other ends of the substrates are configured to collectively form, when mated together, a cylindrical surface  150  adapted to be received by an end cap of a different type; namely a cap having a concave cylindrical opening (see  FIG. 22 ) designed to receive and enclose the cylindrical end  150  of the mated substrates, as shown in  FIGS. 22 and 27D , and thereby capture that end of the substrates. 
     Transverse webs  162  ( FIGS. 22 and 22A ) are advantageously formed at the midpoints (and perhaps other locations as well) of the substrates  152  and  156  to laterally strengthen the tubular structure. Wall strengthening ribs  164  may also be formed in the interior surfaces of the substrates. 
     Referring to  FIGS. 27A and 27B  which are opposing exploded perspective views of the locking mechanism included in the non-threaded latch engaging end cap  146 , it will be apparent that this cap embodiment includes a cylindrical outer side wall forming band  180  and an cylindrical inner band  182  joined on the front side ( FIG. 27A ) by a bezel-like face plate  186  to form a first cap component part  178 . The open space  187  formed on the back side ( FIG. 27B ) by the two wall forming bands is configured to receive the substrate ends  150  as shown in  FIGS. 22 and 27D . Inner band  182  is axially slit at several locations to form latch tabs  190  having upstanding detents at their ends for snap engaging slits  191  formed in a second, “latching component” part  192  of cap  146 . Two channels  194  for providing clearance for the locking tabs  196  are also formed in the inner band  182 . 
     The latching or locking component  192  is comprised of a cap shaped inner body  198  for carrying the locking tabs  196 , and has formed on the front side thereof an outwardly extending web  200  having a strap receiving opening formed therein and a locking handle  204  formed at its outer extremity. As is suggested by the dashed lines, the part  192  is assembled with part  178  by pressing it into the central opening in part  198  until the latch tabs  190  snap into engagement with the slots  191 , at which time the handle  204  is nested in depressions  206  formed in the face plate  186 . At this time the locking cap is fully assembled and ready for attachment to the a body. The back side of the assembled cap is shown in  FIG. 27C . In this figure the locking tabs  192  are shown rotated into their locking position. 
       FIG. 27D  is a partial cross sectional view showing the locking tab  196  in locking engagement with the back side of the substrate web  149 . Note the dark hatched over-molding of the cap perimeter. 
     Turning now to  FIGS. 28A  and B, the front side of the locking cap  146  is respectively shown with it handle  204  in its unlocked and locked positions. 
       FIGS. 29A and 29B  show the inside and outside of the screw-on cap  144 . 
     Referring now to  FIGS. 30-36 , a further alternative embodiment of the present invention will be described. In this embodiment, plane surfaced therapeutic massage pads  210  (for example) are shown attached in the manner described above i.e., by suitable glue, mastic or other suitable means, to the substrates  212 . However, it is to be understood that as pointed out above with respect to the similar embodiment illustrated in  FIGS. 20-29B , either or both of the massage pads  210  may be made of a material having either plain or specifically textured outer surfaces or parts thereof. In addition, whereas one side edge of each substrate is shown to include an elongated channel or groove  166  running from substantially one end of the edge to the other, and the other side edge of each substrate includes an upstanding rib running the length thereof such that when the two substrates are mated together, the ribs enter and mate with the facing channels to maintain alignment of the mating substrate edges, the edges may include a series of discrete channel or groove segments intended to mate with a corresponding 
     series of individual rib segments or the like on the facing side edges. This embodiment is 
     configured to have non-threaded ends similar to those described in the previous embodiment except that in this embodiment the longitudinally extending alignment ribs  214  and grooves  216  formed in the respective side edges of the substrates extend along the full length of the parts. In addition, a different pattern of strengthening ribs  218  and webs  220  may be used. One significant difference is that an apertured annular web  222  (see  FIGS. 31, 33, 35 and 36 ) to which the cap is latched is formed at each end of the assembled substrates as depicted in  FIGS. 35 and 36 . 
     The end caps  223  are also of a different configuration; a three-part snap-together combination of elements (see  FIG. 34 ). Note also that in this embodiment, the user body contacting outer surface of the foam pad  210  is located well below the diameter of the end caps. 
     The end cap parts in this embodiment are shown in exploded view in  FIG. 34  and include a cylindrical outer cap shell  223  having a centrally apertured frontal face plate  224  having an annular recess  225  circumscribing the central aperture  227 , a circular and rotatable locking plate  226  having D-shaped apertures  228  formed therein to define a transversely extending handle and strap tie  230 , a plurality of snap fasteners protruding in a circular array from the back surface, and a pair of rearwardly extending locking tabs  234 . The third element of the combination is a container cap  236 . 
     The end cap is assembled by positioning the plate  226  at the central aperture  227  and pressing it inwardly until the snap hooks  232  snap over the edge of the aperture and engage the back surface  229  locking the plate  226  to the faceplate  225 . However the engagement between the snaps and the faceplate is loose enough to allow rotation of the plate  226  relative to the cap shell  223 . The container cap  236  can then be attached to the plate  226  by snaps or other fasteners. Alternatively, the container cap  236  can be attached to the plate  226  by snaps or other fasteners before the plate  226  is installed in the cap shell  223 . 
     Once the end caps  222  are assembled, they can be attached to each end of the assembled roller body by placing them over the ends of the roller body, aligning the locking tabs with the notches  240  in the web  222  ( FIG. 33 ), and then turning locking handle  230  (and disk  226 ) until the tabs  234  engage detents  241  on the back side of web  222 . 
     Although the present invention has been described herein in terms of several alternative embodiments, it is intended that the present disclosure not be considered limiting, and that the following claims be interpreted as covering all embodiments that fall within the true meaning and scope of the invention.