Abstract:
A fitness/medical device assisting the movement of the lower limbs during the walking activity is substantially composed of brackets firmly connected to the shoes, a set of substantially rigid rods ( 7, 7 A) connecting the brackets with articulation joints ( 6, 6 A,  8, 8 A,  9 ), elastic or inextensible cables for connecting the brackets, and at least one spring ( 5 ) acting between the rods and the connecting cables. The shape and joints of the various components of the kinematic mechanism allows accumulating the energy produced by one of the lower limbs when getting in contact with the ground, in order to give it back to the other lower limb when lifting from the ground, so producing a great reduction of the energy needed in the walking activity and at the same time promoting the acquisition of a correct posture.

Description:
This Application is the National Stage of International Application No. PCT/IB2009/051438, international filing date of Apr. 6, 2009, which claims priority to IT Patent Application No. PI2008A000028, filed Apr. 7, 2008, the entire disclosures of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention concerns a fitness and/or physiotherapy device for personal use, assisting to correctly make steps during the walking activity, assisting to regain functional capacity after pathology and also apt to allow better performances in the walking activity with lower energy consumption. 
     DESCRIPTION OF THE PRIOR ART 
     At present devices for improving effectiveness of the walking activity mainly concern tools aiming to improve a firm support of the foot on the ground, both during the impact phase and during the thrusting phase. 
     Such tools are usually elastic soles or shaped plantars inserted in the shoes and designed to promote a correct posture and to improve the walking performances. 
     Nevertheless the above tools, regardless of their construction quality, work by giving back the elastic power accumulated only to the limb where they are worn and according to a single resonant frequency, determined by the material of the specific tool, whilst they are not able to transfer said power to the opposite lower limb. 
     So, for this reason, they are not able to compensate little or great length differences of the limbs that may cause posture pathologies, nor they are able to optimize the recovery of the power spent in the walking activity in order to improve the performance and decrease the power consumption. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to avoid the above drawbacks of the prior art by providing an assisting device for correctly performing the walking activity able to use the force exerted by one lower limb when it gets in contact with the ground and the plantar bending begins in order to transmit said force to the opposite limb at the appropriate time and directions, so promoting a proper posture while walking. 
     A further object of the present invention is to propose an assisting device for correctly performing the walking activity, able to accumulate energy during the phase in which the foot gets in contact with the ground and the plantar bending begins for transmitting said energy to the opposite limb at the appropriate phase of the walking activity, improving this way the performance of the walking activity itself. 
     The above objects of the present invention are attained by means of a device, assisting the user in the walking activity apt to transfer forces from a lower limb to the other and also apt to promote a correct posture of the lower limbs during the walking activity, characterized in that it comprises: right and left fastening means for connecting to the right and left shoes, apt to create a substantially rigid connection between the soles of the shoes and the fastening means themselves; substantially rigid right and left rods connected together at one end by joints apt to stop at least translation degrees of freedom, and further connected to said fastening means at the other end by further joints apt to stop at least translation degrees of freedom; right and left leverage means connected together at one end by specific connection means and to the fastening means at the other end, the connection to the fastening means being obtained through hinge means apt to stop at least translation degrees of freedom and rotation about an axis transversally crossing the shoe to which the fastening means are bound; and further connection means for connecting said right and left rods to said connection means connecting said right and left leverage means. 
     Specific advantageous embodiments of the present invention are disclosed in the following where the kinematic mechanism formed by said rods, said leverage means, said connection means and the constraints thereof transfer, through said fastening means, the power produced by the lower limb that during the walking activity is getting in contact with the ground, to the opposite lower limb which is approaching the phase of lifting from the ground, said kinematic mechanism applying to the lower limbs forces apt to promote a correct posture of the lower limbs themselves and, in particular, of the feet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       However, for a better understanding of the advantages and characteristics of the present invention, this will now be described by way of an embodiment example, with reference to the accompanying drawings, in which: 
         FIG. 1  shows a front view of a device according to the invention; 
         FIG. 2  shows a back view of the device of  FIG. 1 ; 
         FIG. 3  shows side view of some components of the device of  FIG. 1 ; 
         FIG. 4  shows a side view of the device of  FIG. 1  during a specific working phase; 
         FIG. 5  shows a side view of the device of  FIG. 4  during a different working phase; and 
         FIG. 6  shows a side view of the device of  FIG. 4  during a further different working phase. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 and 2  are schematically shown two brackets,  1  and  1 A, rigidly bound to two standard shoes thanks to screw means transversally crossing the sole of the shoes. 
     To the brackets  1  and  1 A are mounted two operation members,  2  and  2 A, to which are bound, through a hinge having axis parallel to the longitudinal axis of the shoe, two levers,  3  and  3 A, and to which are also bound through ball joints,  6  and  6 A, two rods,  7  and  7 A. 
     Once mounted together the bracket  1  and the operation member  2  thereof form the fastening means integral to the shoe to which they are bound. A similar rigid structure is formed at the opposite side by the left shoe, the bracket  1 A and the operation member  2 A. 
     The rods  7  and  7 A have upper ends mutually connected in a way that allows articulation, the connection being obtained through two more ball joints,  8  and  8 A, further connected to a center ball member,  9 , so that the kinematic mechanism formed by the shoes, the fastening means  1 ,  1 A,  2 ,  2 A, the rods  7  and  7 A and their connection member  9  is able to perform oscillation movements in a sagittal plane, opening out in a front plane, and more complex movements obtained from the combination of the above movements. 
     The levers  3  and  3 A are connected together by two inextensible cables,  4  and  4 A, that are further connected, at the other end, to a traction spring,  5 , acting between said cables  4  and  4 A and the center ball member  9 . 
     A further cable,  10 , connected to the spring  5 , and sliding in a cable sheath,  11 , allows the setting of the spring preload thanks to a ball-grip, not shown in the figures because it is of known techniques, which makes it possible to modify the action of the device according to the distinctive features of the user and according to the kind of utilization, by setting the hardness of the kinematic mechanism in order to obtain a synchronous mechanism oscillating together with the oscillation of the lower limbs or increasing the hardness to an amount that the power produced by one limb is directly transmitted to the opposite limb without accumulation of elastic potential energy in the elastic means of the device. 
     The overall view of  FIG. 1  highlights that the lower limbs are able to adopt postures without any kind of limit imposed by the device. 
     The back view of  FIG. 2  shows the symmetry of this embodiment in the sagittal plane. 
     In  FIG. 3  is shown the left half of the device where is visible the ball joint  6  connecting the operation member  2  with its rod  7  close to the left internal malleolus so underlining that every change of the angular position of the foot affects, through the shoe, the position of the operation member  2  that tends to change the angle that it forms with the rod and, vice versa, every change of the angle between rod and its operation member tend to cause, thanks to a combined action with the spring, a similar change in the shoe and the foot. 
     In the side view of  FIG. 4  is shown the configuration of the device when the left limb gets in contact with the ground with transfer of load that produces plantar bending and changing of the angle between operation member  2 A and rod  7 A. The above change causes rising of the distance between the top end of the lever  3 A, where is connected the cable  4 A, and the center ball member  9 , so producing stretching of the spring  5 . The elastic force of the spring acts, through the system cable  4 , lever  3  and fastening means  1  and  2 , upon the opposite shoe and the foot. As easily intuitable such elastic force may cause lifting of the foot and plantar bending of the right foot, that are anyway prevented until a sufficient amount of body weight charges the limb and there is enough friction of the foot with the ground. 
     It has also to be noted that the angle, in the front plane, between the left operation member  2 A and the hinged lever  3 A produces an off-centre reaction force that tends to inwardly rotate the foot during the step loading phase, according to physiology data pointing out that during such phase of the walking activity an inward rotation of the hip occurs. 
     In  FIG. 5  is shown a subsequent phase of the step cycle, that is a subsequent working phase of the device according to the invention, in which the right limb, no more subject to the body weight, begins a complex movement of thrust and partial retrieval where plantar bending, knee bending and hip bending occur. Such complex movement is assisted by the elastic potential energy of the spring  5  that, acting through the cable  4  upon the lever  3 , produces a reduction of the angle existing in the sagittal plane between the assembly formed by lever  3  and fastening means  1  and  2 , with the rod  7 , and also producing the alignment of this last with the opposite rod  7 A. The angle between the right operation member  2  and the lever  3  induces also an outward rotation of the limb that also in this case matches with the physiology data pointing out that an outward rotation of the hip occurs during the pre-oscillation phase of the step, that is in the last phase of ground contact. 
     In  FIG. 6  is shown a further phase of the step movement in which the retrieval of the right limb is completed, it loses contact with the ground and, after aligning with the opposite limb, it goes further toward a new contact with the ground. In this phase the rods  7  and  7 A tend to align thanks to the remaining stretch of the spring after the foot lifting, so assisting the retrieval of the limb. In  FIG. 6  has also to be noted that, thanks to the way the rods are jointed, the device is prevented from blocking during oscillation of the right limb as the rods tend to tilt toward the left foot touching the ground. At the end of this phase the step cycle starts again for the opposite limb. 
     The above disclosed device allows a consistent reduction of energy expense during the walking activity therefore increasing the performance of the user. 
     Furthermore the device assists at finding the correct and physiologic posture during said activity allowing a gradual and natural postural rehabilitation. 
     The possibility of setting the hardness of the mechanism allows also adapting the device to any kind of user as a function, in particular, of its weight and muscular strength. 
     The device is also very useful in case of specific pathologies or walking problems, such as, for instance, asymmetry of the lower limbs. In this case, in fact, after a physiology analysis, the right and left components of the device may be designed to be asymmetric in order to promote the removal of the lack of balance caused by the asymmetric limbs. 
     Certainly the above advantages remain even if changes or different embodiments of the invention are provided. 
     In fact, advantageously, the rods are made of carbon fiber which is a light and rigid material, but, to reduce costs or for production reasons, it is certainly possible to use different materials which are enough rigid and light like aluminium alloys or other materials. The shape of the rods, that in the disclosed embodiment are straight rods in order to reduce their costs, could vary, in case movements with large angles have to be allowed, and, if so, curved rods could be provided to avoid interference with the lower limbs. 
     Instead of the various ball joints could be used different joining means providing separate articulation for each perpendicular plane, as well as a ball joint could be combined with a joint allowing a single degree of freedom, in order to improve the movement capacity in a specific plane. 
     In particular, the mutual connection of the rods  7  and  7 A could be obtained through a single ball joint, that could replace the two ball joints  8  and  8 A and the center ball member  9 , in order to simplify the structure of the device. 
     The joint corresponding to the tibia-tarsus articulation is placed at the side of the internal malleolus in order to reduce the complexity and the production costs, but, in case obstacles in this area have to be avoided, it can be placed at the side of the external malleolus, providing a curved rod able to connect to the opposite rod in the center sagittal plane in a way that interference with the lower limbs is prevented. 
     The way of fastening the device to the shoes could be obviously different, for instance by using specific sole to be housed in the shoe, or even by realizing special shoes directly comprising brackets  1 ,  1 A. 
     The ball joints and the joints of the spring  5  too could be provided with setting mechanisms so that the hardness of the various components and articulations of the device may be adjusted to fit the needs and size of different users, as well as specifically sized versions of the device could be realized on demand. 
     The ability of accumulating energy that in the disclosed embodiment is attained thanks to the spring  5  could be attained in a different way. In addition, for specific requirements, one or both the cables  4  and  4 A could be replaced by elastic means  41 , and/or the spring  5  could be replaced by an inextensible cable. 
     Obviously the spring  5  could be replaced by elastic means of a different type. 
     The spring setting mechanism made with a ball-grip allows a soft regulation but a more rapid mechanism, such as a lever or an automatic system, may be provided. 
     Finally, a damping mechanism is not provided in the embodiment but, in case it would be suitable, dampers could be mounted at the joints or along the cables. 
     These and more modifications may be carried out, anyway, within the ambit of protection of the following claims