a right shoe 10 according to the invention is shown in fig1 - 3 . a corresponding left shoe is a mirror image of the right shoe and is therefore not described further . the shoe includes an upper 12 that is designed to receive a foot . the upper 12 can be made of any number of materials as is known in the art including mesh and / or leather , and is preferably of a moccasin - type construction . an advantage of the present invention is that since structural support for the foot is provided by the external chassis described below , the upper need not do so , and its weight can be minimized . in the embodiment shown in fig1 and 3 , a conventional lacing system incorporating holes in the upper is used , although other lacing arrangements could be used . the upper further may also include features such as a foam - filled ankle collar 13 surrounding the ankle opening for added comfort . the description of the upper 12 is by way of illustration only ; numerous alternative upper designs will work equally well . mounted on the bottom of upper 12 is an external chassis 14 , which underlies and supports the foot . sole elements 16 , 18 , 20 , 22 , and 24 underlie chassis 14 , and in the preferred embodiment , are attached thereto by an adhesive . the design of chassis 14 is based on the structure and bio - mechanics of the human foot . a top plan view of a right human foot skeleton is shown in fig5 . the foot is attached to the leg ( not shown ) by the talus or anklebone 28 . positioned below and rearwardly of the talus 28 is the calcaneus 30 ( i . e ., the heel bone ). the navicular 32 and the cuboid 34 are positioned below and forward of the talus 28 . three cuneiform bones 36 extend forwardly from the navicular 32 . extending forwardly from the cuneiform bones 36 and from the cuboid 34 are the five metatarsals 38 , which are numbered a through e from left to right in fig5 ( i . e ., from big toe to little toe ). forwardly of each metatarsal bone is a respective phalange 40 that forms the toe . between each metatarsal and its respective phalange is a metatarsal phalangeal ( mtp ) joint . thus , there are five mtp joints in all : a first mtp joint 42 , a second mtp joint 44 , a third mtp joint 46 , a fourth mtp joint 48 , and a fifth mtp joint 50 . these mtp joints can be used to define two axes about which the foot pushes off during certain push - off movements . a lateral push - off axis a 2 is defined by a line running generally through the third ( 46 ), fourth ( 48 ), and fifth ( 50 ) mtp joints . the lateral push - off axis is used for push - offs towards the lateral side . turning now to fig2 chassis 14 is designed to accommodate the natural flexing of the foot about the lateral push - off axes . in the preferred embodiment , chassis 14 is shaped to underlie and support the entire foot . in an alternative embodiment , the chassis underlies the arch and the forward portion of the foot , a heel - supporting sole element is attached directly to the upper . the chassis is preferably made of a relatively stiff , resilient material , such as plastic , fiberglass , or a carbon fiber - containing material for high - performance applications . the embodiment shown in fig1 - 3 includes an arch support flange 52 , the size and shape of which can be varied as required for different foot types and for different sports . notches 56 and 58 at the base of arch support flange 52 provide a predetermined amount of torsional flexure in the middle part of the chassis and shoe . the length and / or width of notches 56 and 58 can be varied as well to provide nearly any amount of torsional rigidity to the shoe . notches 64 and 66 formed on opposite sides of the chassis along axis a 2 &# 39 ;, which underlies the lateral push - off axis ( a 2 ) of the foot . the length and / or width of these two notches can also be varied to produce the desired stiffness and / or flexibility of the shoe about the lateral axis . in the embodiment shown in fig1 slots 70 , 71 and hole 72 are formed in the heel portion of the chassis to provide flexibility in this region . additional slots can be formed within the heel region if desired , and as with the other notches described above , the length and / or width can be modified . chassis 14 also includes medial and lateral heel flanges 80 and 82 respectively to center and retain the heel in place . the embodiment shown in fig1 - 3 includes sole elements 16 , 18 , 20 , 22 and 24 attached to the bottom surface of chassis 14 . as will be appreciated by persons skilled in the art however , more or fewer sole elements of different configurations may be used . sole elements may be positioned to correspond to one or more ground - engaging anatomical structures of the unshod foot . referring to fig5 these points include , but are not limited to , the calcaneus , the head of the first metatarsal , the head of the fifth metatarsal , the base of the fifth metatarsal , the head of the first distal phalange , and the head of the fifth distal phalange . each sole element provides traction , abrasion resistance and cushioning . these functions can be satisfied in many different ways . any of sole elements 16 , 18 , 20 , 22 and 24 can have an outer , abrasion - resistant layer 19 made from a material such as a durable rubber . the outer layer 19 encases a cushioning material 96 such as eva or polyurethane . other embodiments of the sole elements are described further below . in the preferred embodiment , each sole element is affixed to the bottom of the chassis using conventional adhesives , although the invention is not limited thereto . sole element 24 is affixed to the heel portion where it provides traction , and cushions impacts to the calcaneus or heel bone of the foot . element 18 is affixed to the chassis in the region underlying the &# 34 ; ball of the foot &# 34 ;, and provides traction and cushioning for the first metatarsal head . sole elements 20 and 22 support the fifth metatarsal head , and the base of the fifth metatarsal in the lateral midtarsal portion of the foot respectively . sole element 16 is affixed to the chassis below the toe region of the upper , and in other embodiments can extend forward and upwardly around the front end of upper . any number of different surface ornamentations can be applied to these portions , limited only by the creativity and ingenuity of the shoe designer . any of the sole elements 16 , 18 , 20 , 22 and 24 in the preferred embodiment include rounded edges as shown at 22a in fig4 . this feature is explained in greater detail in u . s . pat . no . 5 , 317 , 819 to ellis , which is hereby incorporated by reference . in another embodiment , the sole elements are filled with gas , such as air , or a visco - elastic material . a yet further embodiment of the sole elements is shown in fig9 and 10 . in those figures an individual sole element 160 is shown , which is preferably mounted on the shoe underneath the calcaneus bone , i . e ., the heel . as in the embodiment described earlier , other similar sole elements can be placed in other load bearing points on the shoe corresponding to one or more ground - engaging anatomical structures of the unshod foot , including , but not limited to the calcaneus , the head of the first metatarsal , the head of the fifth metatarsal , the base of the fifth metatarsal , the head of the first distal phalange , and the head of the fifth distal phalange . sole element 160 includes a plurality of air or visco - elastic filled deformation elements 162 , 164 , 166 and 168 . these deformation elements are mounted on a base layer 170 . the deformation elements are preferably elongate , channels extending generally , radially outward from a common origin 176 . the channels are formed by sidewalls 172 extending vertically upward from the base layer to a top , ground - contacting surface 174 and sealed by end - walls to form sealed interior channels 178 . these channels 178 are then filled with a gas , such as air , or a visco - elastic material . a plurality of hollow , intermediate ribs 180 can be mounted on the base plate between adjacent deformation elements . the deformation elements allow the base plate to shift horizontally relative to the ground - contacting surface as a result of impact . this shifting reduces the impact by increasing the amount of time the load is dissipated over . other embodiments of these deformation elements are described in commonly - assigned , copending patent application ser . no . 08 / 327 , 461 filed aug . 16 , 1995 entitled &# 34 ; anisotropic deformation pad for footwear ,&# 34 ; incorporated herein by reference . the shoe according to the invention can work with any of the embodiments shown therein . having described and illustrated the principles of the invention in a preferred embodiment thereof , it should be apparent that the invention can be modified in arrangement and detail without departing from such principles . for example , the design of the sole elements can be modified so that different portions of the upper are exposed than those shown above . an example of such an alternative design is shown in fig1 . in that design the sole elements include a toe element 140 , a forefoot element 146 , and a heel element 148 . two additional forefoot elements 142 and 144 are disposed between the toe portion and the forefoot portion . the lateral element 144 is integrally formed with the main forefoot portion 146 while the medial forefoot element 142 is a separately formed element . these elements are arranged so as to create a flex - groove therebetween as described further above . the heel portion 148 also includes a heel flex groove 150 . unlike the forefoot flex groove , however , the heel flex groove 150 does not necessarily expose the upper . instead the sole element is grooved in this area so as to provide a desired amount of stiffness and / or flexibility in heel area . we claim all modifications and variation coming within the spirit and scope of the following claims .
an athletic shoe including a upper , a support member or &# 34 ; chassis &# 34 ; attached to the underside of the upper , and sole elements attached to the bottom of the support member . the support member provides support for the foot , and thereby permits use of spaced apart sole elements rather than a full midsole and a full outsole . in addition , the support member can be tailored to provide the optimum stiffness for a particular activity or user .