SHOE WITH AN ENERGIZED QUARTER PORTION

Abstract

A shoe with a quarter portion, having an upper, a sole, and a midsole, which further includes a pair of rigid rod-like elements which are coupled rigidly to the sole and/or midsole. The shoe further includes a pair of longitudinally extended flexing springs which are deformable and elastic around the axis of the malleolus of a user who wears the shoe. The flexing springs are adapted to accumulate and return elastic mechanical energy and are integral with the pair of rigid rod-like elements. The shoe further includes a quarter portion assembly that is associated with the pair of flexing springs and is adapted to make contact with a front tibial portion and two lateral portions of the leg of the user.

Claims

1-14. (canceled)

15. A shoe with a quarter portion, the shoe comprising: an upper, a sole and a midsole, a pair of rigid elements coupled rigidly to said sole and/or midsole, a pair of longitudinally extended flexing springs which are deformable and elastic around the axis of the malleolus of a user wearing said shoe and are adapted to accumulate and return elastic mechanical energy and are integral with said pair of rigid elements, and a quarter portion assembly associated with said pair of flexing springs and adapted to contact a front tibial portion and with two lateral portions of the leg, which are contiguous to said portion, of said user.

16. The shoe according to claim 15, wherein said quarter portion assembly comprises a rigid support and a resting element which are mutually associated, said rigid support being articulated to the upper end of said pair of flexing springs.

17. The shoe according to claim 16, wherein said pair of flexing springs comprises respective rigid upper terminals arranged at said upper end of said flexing springs.

18. The shoe according to claim 16, wherein said rigid support is articulated to said upper end of said pair of flexing springs by respective spherical joints, each of said spherical joints comprises a hollow support inside said spherical joint in which a spherical pivot rotates.

19. The shoe according to claim 18, wherein said hollow support is comprised in said rigid upper terminal of said flexing spring and is oriented toward said quarter portion assembly; and in that said spherical pivot is comprised in said rigid support of said quarter portion assembly and is oriented toward said flexing spring.

20. The shoe according to claim 16, wherein said rigid support is articulated to said upper end of said pair of flexing springs by respective coupling elements with a retention element.

21. The shoe according to claim 15, wherein an upper end of said rigid element comprises a cylindrical seat and a lower end of said flexing spring comprises an insert, said insert being inserted in said cylindrical seat, said insert being locked longitudinally in said cylindrical seat by a locking screw engaged in said insert and a locking washer.

22. The shoe according to claim 21, wherein said insert is configured to rotate about the longitudinal axis of said cylindrical seat and said flexing spring is configured to rotate about the longitudinal axis of said rigid element.

23. The shoe according to claim 15, wherein the assembly comprising the upper, the sole and the midsole has a flexural rigidity, in a region of the metatarsal joint, that is proportional to the rigidity of said pair of flexing springs, with respect to their preferential inward flexing plane, said midsole being interposed between said upper and said sole.

24. The shoe according to claim 15, wherein said quarter portion assembly is associated but rotatable with respect to the rigid support around a rotation element that is connected thereto.

25. The shoe according to claim 15, wherein said pair of rigid elements comprises at least one adjustment element configured for adjusting an inclination of said pair of rigid elements.

26. The shoe according to claim 15, wherein said pair of flexing springs is constituted by a material with a ratio between a maximum bending strength expressed in MPa and a flexural elastic modulus, or Young's modulus, expressed in GPa, both understood along a direction of the main flexing plane, greater than or equal to 30.

27. The shoe according to claim 16, wherein said resting element of said quarter portion assembly comprises a padding which is arranged on the internal face and is adapted to contact said front tibial portion and with two lateral portions of the leg that are contiguous to said portion of said user.

28. The shoe according to claim 15, further includes a closure system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further characteristics and advantages of the disclosure will become better apparent from the description of a preferred but not exclusive embodiment of the shoe according to the disclosure, illustrated by way of nonlimiting example with the aid of the accompanying drawings, wherein:

[0021] FIG. 1 is a perspective view of a first embodiment of the shoe with quarter portion, according to the present disclosure;

[0022] FIG. 2 is a lateral elevation view of the first embodiment of the shoe with quarter portion shown in FIG. 1, according to the present disclosure;

[0023] FIGS. 3 and 4 are lateral elevation views which show respectively two different consecutive steps of the operation of the first embodiment of the shoe with quarter portion shown in FIG. 1, according to the present disclosure;

[0024] FIG. 5 is a perspective view of a second embodiment of the shoe with quarter portion, according to the present disclosure;

[0025] FIG. 6 is a lateral elevation view of the second embodiment of the shoe with quarter portion shown in FIG. 5, according to the present disclosure;

[0026] FIG. 7 is an exploded view of a portion, in particular a midsole, of the second embodiment of the shoe with quarter portion shown in FIG. 5, according to the present disclosure;

[0027] FIG. 8 is a sectional view of a portion, in particular a quarter portion assembly, of the second embodiment of the shoe with quarter portion shown in FIG. 5, according to the present disclosure; and

[0028] FIGS. 9 and 10 are sectional views of a portion, in particular a rigid rod-like element, of the second embodiment of the shoe with quarter portion shown in FIG. 5, according to the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] With reference to FIGS. 1-10, the shoe with quarter portion according to the disclosure, designated generally by the reference numerals 10, 60, substantially comprises an upper 14, 64, a tongue 12, 62, a closure system 18, 68, a sole 16, 66 and a midsole 16A, 66A, the midsole 16A, 66A being interposed between the upper 14, 64 and the sole 16, 66.

[0030] The shoe 10, 60 with quarter portion according to the disclosure further is comprises also a pair of rigid rod-like elements 22, 72 with a substantially longitudinal extension which are integral with the sole and/or midsole 16A, 66A, a pair of flexing springs 24, 74 having a substantially longitudinal extension which are integral with the pair of rigid rod-like elements 22, 72, and a quarter portion assembly 32 and 82 associated with the pair of flexing springs 24 and 74.

[0031] The upper 14, 64 and the tongue 12, 62 are typically made of leather or fabric. The closure system 18, 68 is typically provided by means of laces, Velcro buckles, elasticized inserts. The sole 16, 66 is typically made of rubber and derivatives thereof or of natural leather. The insole or midsole 16A, 66A is typically made of thermoplastic polymers or composite materials.

[0032] The rigid rod-like elements 22, 72 of the shoe 10, 60 with quarter portion according to the disclosure are coupled rigidly to the sole 16, 66 and/or midsole 16A, 66A so as to form with them or with part of them a single body.

[0033] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the rigid rod-like elements 22, 72 can be arranged and rigidly coupled to the sole 16, 66 and/or midsole 16A, 66A in a position that is comprised between the outer end of the heel and the region that precedes the resting of the metatarsus and of its natural joint.

[0034] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the rigid rod-like elements 22, 72 can be mutually coupled rigidly by means of an additional rigid rod-like connecting element 23, 73, which is arranged transversely with respect to their longitudinal axis and is coupled rigidly to the respective lower ends.

[0035] The rod-like elements 22, 72 are flexurally rigid along any plane; furthermore, the rod-like elements 22, 72 are also torsionally rigid. The rigid rod-like elements 22, 72 are provided with a geometry and by means of a material that can give them characteristics of flexural and torsional inertia that are at least 5 times greater than those of the elastic elements 24, 74.

[0036] The rigid rod-like elements 22, 72 are inclined toward the rear portion of the shoe on a rotation axis that is perpendicular to the longitudinal axis of the shoe 10, 60 with quarter portion, preferably with an angle comprised between 90 and 160.

[0037] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the rigid rod-like elements 22, 72 comprise elements 20, 70 for adjusting their inclination which are adapted to lock said rigid rod-like elements 22, 72, preventing their movement, in particular rotation. For example, the adjustment elements 20, 70 can be of the friction type with screws, with a reversible ratchet, with a detent, with a friction clutch.

[0038] In an embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the inclination adjustment elements 70 comprise a first block part 92 and a second block part 93, each of which comprises a slot which is adapted to engage the rigid rod-like connecting element 73. The first block part 92 is fixed to the midsole 66A. Once the rigid rod-like connecting element 73 has been positioned in the slots of the block parts 92 and 93, said parts are coupled and fixed by means of a pair of bolts, each of which comprises a screw 94 which is fixed to the midsole 66A and a hexagonal threaded nut 95. Consequently, each one of the block parts 92 and 93 comprises a pair of holes adapted for the passage of the screws 94.

[0039] By acting on these adjustment elements 20, 70 it is possible to modify the inclination of the pair of rigid rod-like elements 22, 72 and consequently the angle formed by these rigid rod-like elements 22, 72 with respect to the longitudinal axis of the shoe 10, 60 with quarter portion, so as to be able to vary the initial or stable geometric configuration of the flexing springs 24, 74.

[0040] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the inclination of the rigid rod-like elements 22, 72 can be chosen, at the design level, with a fixed angle that is characteristic for any user.

[0041] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the rigid rod-like elements 22, 72 have a cross-section which is in any case closed, with any geometry, in addition to the circular one that is shown.

[0042] The flexing springs 24, 74 are deformable and elastic about the virtual axis of rotation of the malleolus of the user and are adapted to accumulate and return elastic mechanical energy when they are deformed and released from the angular variations about the center of rotation of the malleolus proper induced by the resting loads on the plantar arch during the states of motion and/or rest, caused by the simple weight force or by the voluntary muscular activation of the joint on the part of the user.

[0043] The flexing springs 24, 74, with respect to the deformation plane described above, are capable of deforming elastically in a certain and controlled manner, resuming, when the action applied to their end through the quarter portion assembly 32, 82 ceases, by virtue of the accumulated elastic energy, its initial and/or stable geometric shape.

[0044] Even for very small angles of incidence between the foot and the leg which are well beyond the natural possibilities of the joint being considered, their deformation and the consequent stress is always comprised within their elastic limit, being thus inherently safe as regards their state of failure.

[0045] The flexing springs 24, 74 have a substantially longitudinal extension and can have a rectilinear shape or a shape that is curved on one or more axes of curvature.

[0046] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the flexing springs 24, 74 have a substantially rectangular cross-section and their thickness, for the optimization of the mechanical behavior (referred in particular to the functions of the strength modulus and of the inertia modulus) is not greater than 2 mm.

[0047] The flexing springs 24, 74 are rigidly coupled to the respective rigid rod-like elements 22, 72 for example with an interlocking coupling. In is particular, the lower end of a flexing spring 24, 74 is coupled rigidly to the upper end of a respective rigid rod-like element 22, 72 and vice versa.

[0048] In one embodiment of the shoe 60 with quarter portion according to the disclosure, the upper end of the rigid rod-like element 72 comprises a cylindrical seat 102 and the lower end of the flexing spring 74 comprises an insert 104. The insert 104 of the flexing spring 74 is inserted in the cylindrical seat 102 of the rigid rod-like element 72. The insert 104 is locked longitudinally in the cylindrical seat 102 by means of a locking screw 106 which is engaged in the insert 104 and a corresponding locking washer 106, which therefore prevent the exit or extraction of the insert 104 from the cylindrical seat 102.

[0049] Advantageously, the insert 104 is configured to rotate about the longitudinal axis of the cylindrical seat 102, and consequently the flexing spring 74 can rotate about the longitudinal axis of the rigid rod-like element 72. The locking screw 106 also constitutes the stroke limiting block for the rotations of the insert 104 of the flexing spring 74 in the cylindrical seat 102 of the rigid rod-like element 72.

[0050] In different embodiments of the shoe 10 with quarter portion according to the disclosure, the rigid coupling between the ends of a flexing spring 24 and of a rigid rod-like element 22 can be an interlocking coupling defined by resins for adhesive bonding, co-molding of thermoplastic or thermosetting resins, nuts, or other fixing elements capable of ensuring transmission of the maximum rotational torque of the flexing spring 24, related to their preferential inward flexing plane, to the system represented by the sole-upper structure and consequently, with minimal dissipation, to the foot of the user. A rigid rod-like element 22, 72 and a flexing spring 24, 74, which are rigidly coupled, are substantially rectilinear and mutually parallel.

[0051] The flexing springs 24, 74 characterized by a rectangular cross-section and interlocked at their base to the rigid rod-like elements 22, 72 and connected rotatably through the rigid upper terminals 26, 76 and the coupling is elements with hinge-like retention 38 or the spherical joints 88, to the rigid support 34, 84 thus form along the plane that is perpendicular to their preferential flexing plane, a tip that is substantially rigid and stable and is adapted to stabilize and protect lateral rotations of the ankle, by virtue of the lateral contact portions of the leg that are contiguous to the tibial resting of the quarter portion assembly 32, 82.

[0052] It should be noted that in order to ensure user safety, the placement and the inclination of the rigid rod-like elements 22, 72 with respect to the shoe 10, 60 with quarter portion and the shape of the flexing springs 24, 74, must be such as to maintain the flexing arch of the flexing springs 24, 74 in every step of foot-leg flexing in a rear position, i.e., behind the malleolus of the user.

[0053] The upper end of a flexing element 24 comprises a rigid terminal 26, 76. This rigid upper terminal 26, 76 is generally made of thermoplastic or thermosetting material and is connected rigidly to the elastic elements 24, 74 by means of co-molding, adhesive bonding, interference coupling or screw coupling methods.

[0054] In one embodiment of the shoe 10, 60 with quarter portion according to the disclosure, the flexing springs 24, 74 are made of a composite material with a thermosetting matrix with unidirectional glass fibers with a ratio between the maximum bending strength expressed in MPa and the flexural elastic modulus, or Young's modulus, expressed in GPa, both understood along the direction of the main flexing plane, represented by a number that is greater than or equal to 30. Examples of materials compatible with these characteristics are materials known by the acronyms GC-70-UL, GC-70-ULS and GC-70-ULZ manufactured by Gordon Composites.

[0055] The quarter portion assembly 32, 82 is adapted to make contact with a front tibial portion 50 and two lateral portions of the leg, which are contiguous thereto, comprised between the malleolus of the user and the knee, in particular at the minimum anthropometric distance of possible is comfort, from above the malleolus toward the knee, and adapted to connect the pair of flexing springs 24 to said front tibial portion 50 and two lateral portions of the leg of the user which are contiguous to said portion 50.

[0056] The quarter portion assembly 32, 82 comprises a rigid support 34, 84 and a resting element 36, 86 which are mutually associated. The quarter portion assembly 32, 82 is associated with the pair of flexing springs 24, 74, in particular with the respective rigid terminals 26, 76 arranged at their upper ends.

[0057] The rigid support 34, 84 has a substantially semicircular shape. The rigid support 34, 84 is characterized by a circular cross-section up to the point of connection to the rigid upper terminals 26, 76 of the elastic elements 24, 74. In one embodiment of the disclosure, in this connection region the rigid support 84 comprises a spherical pivot 97 in order to allow rotation about one point of the spherical joint 88. In another embodiment of the disclosure, in this connection region the cross-section of the rigid support 34 becomes flat in order to facilitate connection to the coupling elements with hinged coupling 38 and allow the rotation about the axis thereof.

[0058] The rigid support 34, 84 of the quarter portion assembly 32, 82 is made of a material with a high modulus and mechanical strength, preferably but not exclusively made of a material of the metallic type, such as for example light aluminum alloys or made of composite material such as carbon fibers in a thermoplastic or thermosetting matrix and also made of thermoplastic molding resins reinforced with short fibers made of carbon, metal or glass.

[0059] The rigid support 34, 84 of the quarter portion assembly 32, 82 is articulated rotatably to the upper end of both of the flexing springs 24, 74, in particular to the respective rigid upper terminals 26, 76.

[0060] In one embodiment of the shoe 60 with quarter portion according to the disclosure, the rigid support 84 of the quarter portion assembly 82 is articulated rotatably to the upper end of both of the flexing springs 74 by means of respective spherical joints 88. Each spherical joint 88 comprises a is hollow support 96 inside which a spherical pivot 97 rotates. The hollow support 96 is comprised within the rigid upper terminal 76 of the flexing spring 74 and is oriented toward the quarter portion assembly 82. The spherical pivot 97 is comprised in the rigid support 84 of the quarter portion assembly 82 and is oriented toward the flexing spring 74.

[0061] In this case, the rigid support 84 of the quarter portion assembly 32 has a rotation axis that is triaxial with respect to the axis of longitudinal extension of the flexing spring 24.

[0062] In another embodiment of the shoe 10 with quarter portion according to the disclosure, the rigid support 34 of the quarter portion assembly 32 is articulated rotatably at the upper end of both of the flexing springs 24 by way of respective coupling elements with hinge-like retention 38.

[0063] In this case, the rigid support 34 of the quarter portion assembly 32 has a rotation axis that is perpendicular with respect to the axis of longitudinal extension of the flexing spring 24.

[0064] The resting element 36, 86 of the quarter portion assembly 32, 82 is constituted by an ergonomic quarter element, preferably made of plastic material or composite material, which has an internal face and an external face that is opposite the internal one. The internal face of the resting element 36, 86 is adapted to make contact with the front tibial portion 50 and two lateral portions of the leg, which are contiguous to said portion 50, of the user. The outer face of the resting element 36, 86 is adapted to make contact with and rotate about the circular profile of the rigid support 34, 84, with which the external face is associate by means of a band-like rotation element 40, 90.

[0065] In one embodiment of the disclosure, the resting element 36, 86 of the quarter portion assembly 32, 82, in particular its internal face, comprises a padding which is adapted to make contact with the front tibial portion 50 and two lateral portions of the leg, which are contiguous to said portion 50, of the user, in a comfortable and ergonomic manner. This padding is preferably is made of material comprised within expanded resins. For example, the padding can be provided by means of material commercially known as Poron, manufactured by the Rogers Corporation.

[0066] In one embodiment of the disclosure, the resting element 36, 86 of the quarter portion assembly 32, 82 is associated with the rigid support 34, 84 of the quarter portion assembly 32, 82 by means of a band-like rotation element 40, 90 connected thereto, shaped so that the resting element 36,86 can rotate about the circular profile of the rigid support 34, 84, remaining in any case associated therewith.

[0067] In this manner, with particular reference to FIGS. 3 and 4, it is understood that the shortening of the elastic elements 24 during their flexing can change the angle of incidence between the tangent of their deformed shape (, 1, 2) and the rigid support 34, which by being able to rotate about the resting element 36 through the band-like rotation element 40, does not allow said resting element 36 any type of sliding between it and the portion that is engaged thereby of the leg of the user.

[0068] The shoe 10, 60 with quarter portion according to the disclosure is configured so that the user, by wearing it, induces a deformation of the flexing springs 24, 74, for example for a normal upright posture.

[0069] The shoe 10, 60 with quarter portion according to the disclosure is therefore a shoe that is energized by means of the preloading of the flexing springs 24, 74 induced by contact between the tibial portion 50 engaged by the quarter portion assembly 32, 82 connected thereto, which in this manner, for example during the gesture of walking or running, release the energy accumulated by position and weight force, returning it in the automatic opening of the ankle and consequently facilitating also the backward rotation of the leg around the knee as well as the horizontal propulsion in the separation of the metatarsus from the ground.

[0070] The best but not unique adjustment of this effect is achieved when aligning maximally the foot with the leg, the quarter portion assembly 32, 82 is and in particular the resting element 36, 86, still maintains a slight contact with the leg portion of the user, understood, in this case, as the front tibial part 50 that is engaged by the quarter portion element 36, 86.

[0071] Advantageously, the embodiment of the shoe 60 with quarter portion according to the disclosure comprising the spherical joints 88 and/or in which the upper end of the rigid rod-like element 72 comprises a cylindrical seat 102 and the lower end of the flexing spring 74 comprises an insert 104, does not condition and/or force a preferential flexing plane of the flexing springs 74 but rather entrains said flexing springs 74 on a plurality of flexing planes without conditioning its preferential flexing plane.

[0072] These flexing planes are determined and comprised by the possible angles of rotation determined by the movement of the insert 104 of the flexing spring 74 in the cylindrical seat 102 of the rigid rod-like element 72 and by the possible rotation angles determined by the movement of the spherical joints 88.

[0073] In this manner one obtains a portal the flexing of which, while always respecting the preferential flexing plane of the flexing springs 74 (therefore without ever inducing therein torsional tensions or tensions which are in any case harmful for their operation and lifespan), can be oriented in a larger angular field and consequently it is more compliant with the natural angular mobility between the foot and the leg along their rotational geometries around the malleolus.

[0074] Advantageously, for a better distribution of the elastic mechanical energy, the shoe 10, 60 with quarter portion, in particular the corresponding assembly comprising the upper 14, 64, the sole 16, 66 and the midsole 16A, 66A, must have a flexural rigidity I*E, in the region of the natural joint of the foot related to the metatarsal arch, equal to twice (there being a pair of flexing springs 24, 74) the rigidity I*E of a flexing spring 24, 74.

[0075] The rigidity I*E of the upper/sole/midsole assembly of the shoe 10, 60 with quarter portion can decrease or fade out as one proceeds toward the tip or the toe containment region, while it can increase as one proceeds toward the heel or the heel containment region.

[0076] Operation of an embodiment of the shoe with quarter portion according to the disclosure is described hereinafter.

[0077] In the normal perfectly upright posture of the human body, the weight force is transmitted to the resting regions at the foot, through the center of the joint of the knee and of the malleolus, which lie more or less on the same vertical axis.

[0078] In this condition, the load of the weight force is distributed on the foot by means of the resting regions of the metatarsal arch and of the heel, with a distribution that is inversely proportional to their distances from the center of the malleolus, which can be generally approximated to a value of on the metatarsal arch and of on the heel.

[0079] This type of posture of the human body also does not generally represent a state of relaxation of the muscles, since they must control its balance by means of small but continuous contractions and extensions.

[0080] The state of best muscle relaxation and accordingly of minimum internal energy consumption occurs when, with respect to a static sitting posture, with the upper portion of the weight force of the human body that bears on the ischia of the pelvis, and the one related to the lower limbs, resting on the feet, the angle comprised between the lower part of the leg and the resting foot forms an angle of approximately 120.

[0081] Otherwise, during a movement, related to the use of the lower limbs with resting of the weight force through the feet, or even during a step of imposed posture, with the angle comprised between the foot and the lower part of the leg that is greater or smaller than 120, the distribution of the weight force changes value and in particular for angles comprised between the foot and the lower part of the leg of less than 120 said force increases its own value on the metatarsal arch, relieving it from the heel, consequently generating the need, for the integrity of the muscle-skeleton-ligament system, as well as for the activation of the muscle contractions related to the movement being considered, for a contraction of the gastrocnemius muscle and of its natural antagonists, such as for example the vastus medialis muscle and the upper quadriceps muscle or rectus femoris muscle, as well as the tibial muscle and the tendons of the toes that converge therein.

[0082] An angular variation between the upper part and the lower part of the leg and between the latter and the foot, caused in general by the imbalance of the center of gravity of the human body in order to perform a movement or by a simple posture of less than complete muscle rest, the weight force that passes through the center of rotation of the knee produces a rotation torque on the malleolus that must be contrasted by reaction upon the resting of the metatarsal arch and by the corresponding torque.

[0083] By applying to the human body, in particular to the foot of the user, the shoe 10, 60 with quarter portion according to the disclosure, these torques induce, only due to the weight force that imbalances the center of gravity of the human body, an elastic deformation on the flexing springs 24, 74, which are thus adapted to accumulate this energy source, and to relieve the contraction of the gastrocnemius muscle and the contractions of its natural antagonists.

[0084] The elastic energy accumulated by the flexing springs 24, 74 during loading further contributes, as an additional artificial muscle activated simply by the energy related to the position weight force of the compass of the lower limbs, during the typical angular variations of the motor or rest states and/or by the imbalance of the center of gravity of the human body, with an increase of the weight force on the metatarsal arch, to remove part of said energy from the contraction of the gastrocnemius muscle and of the contractions of its natural antagonists, such as for example the vastus medialis muscle and the upper quadriceps muscle or the rectus femoris muscle.

[0085] In this manner, the forces involved are redistributed on a much larger portion of the muscles, and in particular on the gluteus, i.e., the largest motor is muscle of the human body and the less distal one from the cardiac pump, which are subject moreover to lower stress, and therefore to a lower energy demand, increasing considerably the energy efficiency described previously.

[0086] In even greater detail, during the step of return or cessation of the load, the energy accumulated in the flexing springs 24, 74, in addition to relieving the contraction tension of the gastrocnemius and of its antagonists, during the loading step, and removing a good part thereof, is returned to augment and stabilize, with an almost nil energy cost, part of the natural torques, determined by the anterior and posterior muscles of the lower limbs, for restoring the angles at the knee and malleolus, which are typical of their pendulum-like motion or of their position of minimum energy demand related to the required movement or postural action.

[0087] Not least, by wearing the shoe 10, 60 with quarter portion according to the disclosure, and in particular by means of the rigidity of the portal represented by the two rigid rod-like elements 22, 72 that connect the flexing springs 24, 74 to the rigid support 34, 84, and consequently to the quarter portion assembly 36, 86, in particular in the regions of contact which are lateral to the leg and are contiguous to the resting of the tibia 50, the excessive and damaging internal and external lateral rotations of the ankle, are protected and limited within a safety interval. In this manner, without forcing excessively the necessary lateral articulation, the state of balance and stability is facilitated, relieving from excessive tensions the muscle-ligament-skeletal system that is assigned to this task.

[0088] In practice it has been found that the disclosure achieves fully the intended aim and advantages. In particular, it has been shown that the shoe with quarter portion thus conceived allows to overcome the qualitative limitations of the prior art, since it allows to accumulate and return energy substantially only of a gravitational nature, in order to augment and stabilize the muscle-skeletal-ligament system of the human body that is subject to the weight force transmitted by the contact of one or both feet and consequently is the states of motion or rest related to all non-horizontal positions of the human body that are subject to the same gravitational weight force.

[0089] This allows to obtain a considerable energy saving and a consequent increase in efficiency, understood as the ratio between the mechanical work performed and the energy supplied to a system during the states of motion or rest of the human body, related to the upright position or in any case with the foot resting, related to a non-horizontal posture.

[0090] One advantage of the shoe with quarter portion according to the disclosure resides in that it is also capable, during a falling step, such as for example in the return step in jumping, of damping decelerations caused by the impact of the foot on the surface, relieving the muscle-skeletal-ligament system of the human body from weight forces that are subject to accelerations that exceed static gravity.

[0091] Another advantage of the shoe with quarter portion according to the disclosure resides in that it offers a high level of comfort to the user who benefits from it by using it, minimizing the difficulties in fit and accessibility and maximizing, not least due to a very low weight, the results in terms of metabolic benefit/saving and performance increase. Furthermore, the shoe with quarter portion according to the disclosure allows an optimum distribution of the pressure that is created between said shoe and the leg of the user during use.

[0092] A further advantage of the shoe with quarter portion according to the disclosure resides in that it can be provided by using materials that are commonly used and production processes which are relatively simple or in any case not excessively sophisticated.

[0093] Another advantage of the shoe with quarter portion according to the disclosure resides in that it can be used in various fields, states of motion and/or steps of walking as well as also for various static postures and not limited to a specific field, state of motion and/or step of walking or posture.

[0094] The disclosure thus conceived is susceptible of numerous modifications is and variations, all of which are within the scope of the appended claims. All the details may further be replaced with other technically equivalent elements.

[0095] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements of the state of the art.

[0096] To conclude, the scope of the protection of the claims must not be limited by the illustrations or preferred embodiments shown in the description by way of example, but rather the claims must comprise all the characteristics of patentable novelty that reside in the present disclosure, including all the characteristics that would be treated as equivalents by the person skilled in the art.

[0097] The disclosures in Italian Patent Application no. 102017000047889, from which this application claims priority, are incorporated herein by reference.