ITUA20163575A1 - Articulated foot-ankle orthosis with floating axis of rotation - Google Patents

Description

"Articulated foot-ankle orthosis with floating axis of rotation"

DESCRIPTION

TECHNICAL FIELD

The present invention refers to the biomedical sector and, specifically, to orthotic devices.

More precisely, the present invention relates to foot-ankle orthoses; even more precisely, the present invention refers to articulated foot-ankle orthoses which are commonly used in the orthopedic-rehabilitation field. The articulated orthosis according to the present invention finds a preferred and advantageous application for the foot-ankle, but it can also be applied to a knee or an elbow and, in general, for the treatment and cure of injuries to the musculoskeletal or neurological system.

STATE OF THE ART

A <7> orthosis is a tool applied externally and used to support, align, prevent or correct the function of moving parts of the body; in particular, the foot-ankle orthoses (AFO, Ankle Foot Orthosis) are applied to the ankle-tarsal joints (between the leg formed by the tibia and fibula bone segments, and the tarsus, i.e. the hindfoot, in particular the talus) and subtalar ( between the talus and the calcaneus), exercising at the same time actions both of support and correction of possibly deficient functionality, and of motion constraint to protect anatomical structures injured in post-trauma treatments (see citations [1], [ 2] and [3]).

Among the different types of foot ankle orthoses are known those called articulated orthoses or "Hinged AFO (HAFO)", ie foot-ankle orthosis in which there are two rigid hulls, relating to the foot and leg of a user, connected by joints that allow the relative movement, in particular the flexion and extension movements (dorsiflexion and plantarflexion of the foot), within a certain interval delimited by appropriate stops, while contrasting more or less vigorously the movements in the other planes; articulated foot-ankle orthoses can have numerous applications, as in the case of users suffering from a foot fall or pendant, club foot, hemiplegia and other pathologies of the lower limb.

The connecting joints of the hulls are in current articulated orthoses usually of the rotoidal type with a fixed axis or, more generally, they are kinematic chains that allow a limited number of relative degrees of freedom; therefore, a common feature of the aforementioned articulated foot-ankle orthoses known up to now is the fact that they have an axis of rotation that does not respect the physiological conditions of the articular kinematics of the ankle (see quotation [3]), which instead moves from position to position (see citations [3], [4], [5], [6] and [7]); a scientific publication concerning the study of the joint kinematics of the ankle, in particular a method for identifying the behavior of the natural joint axis through movement analysis (see citation [8]), states that the ankle works as a single degree joint of freedom, whose axis of rotation rotates and moves during the execution of the joint movement, based on the coupling between the bone segments and the action of the ligaments; another recent study (see citation [3]) conducted through movement analysis on this type of orthosis with a configurable axis of rotation, has shown that the position of the joint in a traditional articulated orthosis significantly affects the angular movement of the sub-articulated joints. talars and on the overall execution of the walk not allowing to obtain a physiological condition of walking.

In other words, the natural movement of the ankle, here defined as relative motion between leg and foot considered as rigid segments, can be assumed as a helical motion whose axis does not remain fixed, but varies in position and orientation with respect to these rigid segments. ; this implies that the constraint imposed by the traditional orthosis on the user's joint determines an unnatural movement, which can cause, in continued use, undesirable and harmful effects both to the structures of the joint concerned and to the adjacent joints.

Currently, the most widely used articulated orthotic models are generally classified as follows:

- with simple hinge, with or without limitation of range of motion or "Range of Motion" (ROM), with or without elastic resistance proportional to rotation; with bar joints, ie with two joints, arranged in a medial and lateral position, each consisting of a rigid bar hinged at the ends by two hulls which confer two degrees of freedom in the sagittal plane;

- "Tamarack", ie with the two hulls connected by flexible elements in a medial and lateral position, which allow relative motion with greater freedom with respect to the hinge; - with polycentric joint, in which the relative motion between the two hulls follows a predetermined trajectory.

In particular, the articulated foot-ankle orthoses described in the International application published under no. WO 2014/060824 A1 and in US Patents No. US 5,086,760 and no. US 5,094,232.

The International application published under no. WO 2014/060824 A1 illustrates an articulated foot-ankle orthosis comprising joint, leg shell and foot shell, in which the joint allows a single degree of freedom roto-translation between the leg shell and that of the foot; in particular, this rototranslation movement depends on the geometry of the joint which, by means of two movable pins in two corresponding grooves, constrains and defines the trajectory of this movement.

The aforementioned technical solution, while addressing the problem of allowing natural movement during walking, in particular allowing the foot to perform natural flexion-extension movements according to a rototranslatory motion, is limited from the point of view of functionality as it allows only one degree of freedom between the hulls; in particular, this solution alters the natural joint kinematics of the ankle, which cannot be represented as a rotation around a fixed axis.

II US Patent No. US 5,086,760, on the other hand, relates to a joint which allows the flexion-extension movement by means of rotation around the axis of a pin; the joint, thanks to two spherical surfaces, also allows the inversion movement, in which the two rotation axes are constrained to pass through a fixed point at the center of the spherical surfaces themselves; it is therefore a joint with two degrees of freedom, with the possibility of adjusting the end stops of the two rotations.

The aforesaid technical solution has the disadvantages of allowing only two degrees of freedom of rotation around axes forced to pass through a fixed point; in particular, this solution alters the natural joint kinematics of the ankle, which cannot be represented as a two-degree-of-freedom movement.

II US Patent No. US 5,094,232 refers to a joint which allows three degrees of freedom on the sagittal plane thanks to the presence of two flat plates, each provided with a groove, and arranged at 90 ° to the other; the two plates, always in contact with each other, are coupled through a sphere, so as to allow movements of horizontal translation, vertical translation and rotation in the sagittal plane.

The aforementioned technical solution has the disadvantages of allowing only three degrees of freedom in the sagittal plane of the orthosis, possibly being able to obtain a further two degrees of freedom (relative rotations in the frontal plane and in the transverse plane) but acting on the deformability of the attachments to the hull of the leg. and not thanks to the joint itself; in particular, this solution alters the natural joint kinematics of the ankle, which requires six relative degrees of freedom between the leg and foot segments.

Therefore, all the solutions known so far, including those previously exposed, do not allow to realize six degrees of freedom of relative movement, that is to say three degrees of freedom in the sagittal plane (flexion-extension rotation, horizontal translation and vertical translation) , a fourth degree of freedom in the frontal plane (inversion-eversion rotation), a fifth degree of freedom in the transverse plane (abduction-adduction rotation) and a sixth degree of freedom in the mediolateral direction (translation).

Consequently, none of the known solutions has an articulated orthosis capable of not altering the natural movement of the foot-ankle joint.

Furthermore, none of the known solutions has an articulated orthosis such that the relative movement between the two hulls is guided by the structures of the natural joint and, at the same time, is provided with restraining elements which allow to compensate for any weaknesses or necessary protections. functional, of the natural containment structures.

Furthermore, none of the known solutions provides for the design and construction of an articulated orthosis on the basis of the physiological characteristics of the individual user by means of the customized adaptation of a joint with two hulls produced according to industrial standards and methodologies, i.e. none of the known solutions can be adapted for the specific needs of each individual user.

In the current panorama, despite the considerable technological development and the variety of articulated orthoses available, it is still difficult to combine the maximum effectiveness on the therapeutic-rehabilitative level with an increased comfort of use and, even more problem, it is often necessary to purchase different orthoses for the different therapeutic-rehabilitative phases of a user.

Therefore, the need to have an articulated orthosis, and more precisely a relative joint, capable of achieving six degrees of freedom of movement, i.e. three degrees of freedom in the sagittal plane (rotation, translation horizontal and vertical translation), a fourth degree of freedom in the frontal plane (rotation), a fifth degree of freedom in the transverse plane (rotation) and a sixth degree of freedom in the medio-lateral direction (translation).

Furthermore, the need to have an articulated orthosis, and more precisely a relative joint, capable of guaranteeing a relative movement between the two hulls that respects the physiological constraints of the natural joint, remains unsatisfied.

Furthermore, the need to have an orthosis in which the relative movement between two hulls is guided by the structures of the natural joint and which, at the same time, is provided with restraining elements that allow to compensate for any weaknesses, remains unsatisfied. , or necessary functional protections, of the natural containment structures.

Furthermore, the need to have a single articulated orthosis, and more precisely a single relative joint, adaptable to different users and, in relation to a single user, adaptable to the different therapeutic rehabilitative phases remains unsatisfied.

Furthermore, the need to contain production costs remains unsatisfied, in particular for mass production.

PURPOSE AND SUMMARY OF THE INVENTION

It is an object of the present invention to overcome the drawbacks of the known art in the field of orthotic devices, specifically of articulated orthoses.

More precisely, the present invention intends to solve the problem of having an articulated orthosis in which the connection joint between the two hulls allows a movement relative to six suitably limited degrees of freedom, so as to guarantee a physiological behavior of the joint of the user and, at the same time, compensate for any weaknesses of the natural containment structures, or provide them with necessary functional protections.

In particular, the purpose of the present invention is to provide an articulated orthosis equipped with an innovative joint for the connection of the two hulls which, unlike a traditional joint with a fixed axis which limits the relative motion to a single degree of freedom, allows a relative more shaft movement, which is thus more easily guided by the structures of the natural joint even if within a confined space (flexion-extension movements are favored, while the other movements are limited, i.e. pronation-supination, the ab-adduction and the three joint translations).

Even more particularly, the object of the present invention is to provide an articulated orthosis that adapts the relative movement of the same hulls to that of the instantaneous helical axis (IHA) typical of the natural ankle, thanks to the provision of a joint with floating rotation axis for connecting the two hulls of the orthosis and positioning the average axis of the floating joint coinciding with the "ideal" axis of the user's ankle (this "ideal" axis being assumed to correspond to the average axis helical (MHA, Mean Helical Axis).

Furthermore, the purpose of the present invention is to provide an articulated orthosis that can be adapted to any user and also to the different therapeutic rehabilitative phases of a single user, thanks to the design and construction based on the specific kinematic characteristics of the user's ankle, obtained through adequate tools and motion analysis protocols.

The aforesaid and other objects and advantages of the invention, as will emerge from the following description, are achieved with an articulated orthosis such as that according to claim 1.

Preferred embodiments and variants of the orthosis of the present invention are the subject of the dependent claims; in particular, in a preferred and advantageous embodiment, the articulated Tortesi according to the invention provides means for adjusting the positioning of the joint.

In a further preferred and advantageous embodiment, the articulated Tortesi according to the invention provides first or second elastic deformable elements, respectively transversal or axial, to control the play of the joint more precisely.

It is understood that all the attached claims form an integral part of the present description and that each of the technical characteristics claimed therein is possibly independent and can be used independently with respect to the other aspects of the invention.

It will be immediately evident that innumerable modifications (for example relating to shape, dimensions, arrangements and parts with equivalent functionality) can be made to what has been described without departing from the scope of protection of the invention as claimed in the attached claims.

Advantageously, the technical solution according to the present invention which provides an articulated orthosis with an instantaneous helical axis (IHA) floating around the average helical axis (MHA) of the user's ankle, allows:

- the reproduction of natural movement in the user's ankle;

- the possibility of carrying out six relative movements, three in the sagittal anatomical plane, one in the frontal anatomical plane, one in the transverse anatomical plane and one in the mid-lateral direction;

- adaptability to any user and customization to his specific needs and also, for each user, to the different phases of the motor rehabilitation treatment; - greater efficacy from the therapeutic-rehabilitative point of view;

- excellent user comfort combined with significant pain relief; - ease of adjustment;

- high durability, light weight and low friction;

- simple and low-cost series construction, also thanks to the possibility of using 3D printing technology.

Further advantageous characteristics will become more evident from the following description of preferred but not exclusive embodiments, provided purely by way of non-limiting example.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described hereinafter by means of some preferred embodiments, provided by way of non-limiting example, with reference to the attached drawings. These drawings illustrate different aspects and examples of the present invention and, where appropriate, similar structures, components, materials and / or elements in different figures are indicated by similar reference numerals.

FIG. 1 is a partially transparent perspective view of the articulated orthosis according to the present invention comprising joint, leg shell (upper part) and foot shell (lower part);

FIG. 2 is an exploded perspective view of FIG. 1;

FIG. 3 shows a side view (top) and a plan view (bottom) of FIG. 1; FIG. 4A shows a side view (top) and a plan view (bottom) of the leg shell of FIG. 3 with the parts of the joint integral with it;

FIG. 4B shows a side view (top) and a plan view (bottom) of the foot shell of FIG. 3 with the parts of the joint integral with it;

FIG. 5A illustrates a first relative movement, of rotation in the sagittal plane, in the system of FIG. 3;

FIG. 5B illustrates a second relative movement, of horizontal translation in the sagittal plane, in the system of FIG. 3;

FIG. 5C illustrates a third relative movement, of vertical translation in the sagittal plane, in the system of FIG. 3;

FIG. 5D illustrates a fourth relative movement, of rotation in the frontal plane, in the system of FIG. 3;

FIG. 5E illustrates a fifth relative movement, of rotation in the transverse plane, in the system of FIG. 3;

FIG. 5F illustrates a sixth relative movement, of translation in the mediolateral direction, in the system of FIG. 3;

FIG. 6 is a cross-sectional view of the joint of FIG. 1;

FIG. 7 is a perspective view, partially in transparency, of a first alternative embodiment, with joint positioning plates, of the articulated orthosis according to the present invention;

FIG. 8 is an exploded perspective view of FIG. 7;

FIG. 9A is a cross-sectional view of a first variant of the joint, equipped with viscoelastic elements deformable in the axial direction, of the articulated orthosis according to the present invention; And

FIG. 9B is a cross-sectional view of a second variant of the joint, equipped with viscoelastic elements deformable in the radial direction, of the articulated orthosis according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications and alternative constructions, some preferred embodiments are shown in the drawings and will be described in detail below.

It is to be understood, however, that there is no intention of limiting the invention to the specific embodiments illustrated, but, on the contrary, the invention is intended to cover all modifications, alternative constructions, and equivalents that fall within the scope of the invention as defined in the claims.

In the following description, therefore, the use of "for example", "etc.", "or", "or" indicates non-exclusive alternatives without any limitation, unless otherwise indicated; the use of "also" means "including, but not limited to" unless otherwise indicated; the use of "includes / includes" means "includes / includes, but not limited to" unless otherwise indicated.

The articulated orthosis of the present invention is based on the consideration that the natural movement of the ankle can be interpreted as a motion according to an Instantaneous Helical Axis (IHA), floating around a Mean Helical Axis (MHA) ; the beam of the instantaneous axes IHA and the corresponding average axis MHA of the user receiving the orthosis can be determined with known motion analysis tools and protocols through for example stereophotogrammetry, use of inertial sensors, fluoroscopy. The fundamental characteristic of said articulated orthosis lies in the fact of providing a floating joint for the connection of the two hulls of the orthosis, which adapts the relative movement of the hulls to that of the bundle of the IHA instant helical axes of the user's ankle, and to position Average joint tax coinciding with the user's ankle MHA helical average tax.

As aforesaid, it is possible to carry out the kinematic analysis of the relative motion between two rigid bodies, that is, in particular between the two hulls of the articulated orthosis, by identifying IHA and MHA with known calculation methods and procedures. Such methodologies can also be applied for the in vitro kinematic identification of human joints, as described in a previous study (see citation [8]) ·

The in vivo application of these methodologies, i.e. possibly on the recipient user of the orthosis, instead entails significant problems, determined in particular by the multisegmentality of the foot and the presence of soft tissues, which generate a spurious movement between the necessarily skin markers and the segments. underlying bone, target of the measures. Thinking for example of using stereophotogrammetry, these markers must be applied to the user, whose spatial coordinates are detected for different movements, such as walking, free or forced flexion extension of the ankle, both active and passive, etc., and processed with mathematical algorithms that allow you to calculate and graphically represent, in a three-dimensional space, the instantaneous helical axes IHA and average helical tax MHA. It should be emphasized that, in order to apply this methodology, it is necessary to identify a rigid body model of the foot, an operation affected by high numerical noise which produces high values of dispersion of the results; to achieve effective kinematic identification of the ankle it will therefore be necessary to apply also filtering techniques and optimization of the calculated values.

The average axis MHA of the bundle of instantaneous axes IHA, thus calculated, then allows the definition of the average axis of the joint that connects the two hulls.

On the basis of the above, the articulated Tortesi of the present invention is equipped with an innovative joint for the connection of the two hulls which, unlike the traditional fixed axis rotational joints which limit the relative motion to a single degree of freedom, or other solutions that allow some further degrees of freedom, allow a completely free relative movement, which is thus more easily guided by the structures of the natural joint even if within a confined space (flexion-extension movement is favored, while they are more limited the other movements, that is the pronation -supination, the abadduction and the three articular translations); in this way, during walking, Tortesi allows the natural joint movement defined by the passive articular structures (capsule, cartilaginous contact surfaces and ligaments) between the bone segments, but exercising a constraint function with respect to the movements that are in the non-injured joint usually limited by the physiological containment structures just mentioned above.

Referring to Figs. 1 and 2, articulated Tortesi 1 according to the present invention which comprises

a first hull 2 to be associated with a foot 20,

- a second shell 3 to be associated with a leg 30, e

- a pair of joints 10.

Preferably the first hull 2 and the second hull 3 are made of thermoplastic material and are padded with polyurethane sponge; preferably the first shell 2 to be associated with the foot 20 is provided with an anti-slip sole, for example made of rubber; preferably the second shell 3 to be associated with the leg 30 is provided with closure means, for example with one or more Velcro strips; preferably the areas of the hulls near the joint are reinforced with riveted metal plates.

Joint 10, in turn, understands

a first internal plate 4 integral with the first shell 2 on the side opposite the foot 20,

- a second external plate 5 integral with the second hull 3 on the side opposite the leg 30 and equipped with a hole 50,

- a spacer 6,

- a threaded counter plate 7, e

a connecting pin 8 integral with said first internal plate 4 and whose head abuts on said first hull 2 on the opposite side to said first internal plate 4.

In the present description, the term "internal plate" means the plate connected to the shell of the foot, while the term "external plate" means the plate connected to the shell of the leg.

The hole 50 of the second outer plate 5 has a larger diameter than the diameter of the spacer 6 to obtain a reciprocal radial clearance.

Furthermore, the distance between the external surface 40 of the first internal plate 4 and the internal surface 70 of the threaded counter-plate 7, determined by the length of the spacer 6, is greater than the thickness of the second external plate 5 to obtain a reciprocal axial clearance.

As can be clearly seen in Figs. 2 and 6, the first inner plate 4 is connected with the first hull 2 on the opposite side with respect to the foot 20, the second outer plate 5 is connected with the second hull 3 on the opposite side with respect to the leg 30, the spacer 6 passes through the hole 5 of the second outer plate 5 and is arranged in contact with the first inner plate 4 and the threaded counter-plate 7 is arranged in contact with the spacer 6.

In this way, the rotation rate of the pair of joints 10 is floating around the MHA of the joint of a user so that the joint tortesi 1 follows the natural kinematics of the joint of a user.

In particular, a pair of joints 10 allows the first hull 2 and the second hull 3 a movement relative to six degrees of freedom consisting of two independent translations in the sagittal plane (as visible, respectively, in Figs. 5B and 5C), a translation in the medio-lateral direction (as seen in Fig. 5L), a rotation in the sagittal plane with respect to a mid-lateral axis (as seen in Fig. 5A), a rotation in the frontal plane with respect to an antero-posterior axis (as seen in Fig. 5D) and a rotation in the transverse plane with respect to a longitudinal axis of the leg (as visible in Fig. 5E).

Figs. 3, 4A and 4B show that articulated Tortesi 1 comprises a pair of joints 10; The coupling between the two hulls 2 and 3 is achieved by a pair of joints 10 which allow relative movements of defined amplitude, in particular as regards the rotation and the two translations in the sagittal plane, the translation in the medio-lateral direction, the rotation in the frontal plane with respect to an anteroposterior axis and rotation in the transverse plane with respect to a longitudinal axis.

The difference between the external diameter of the spacer 6 and the diameter of the hole 50 of the second external plate 5 allows three degrees of freedom in the sagittal plane; the difference between the thickness of the second outer plate 5 and the distance between the outer surface 40 of the first inner plate 4 and the inner surface 70 of the threaded counter-plate 7, imposed by the length of the spacer 6, allows the further translation movements in the direction medio-lateral and rotation in the frontal plane and in the transverse plane.

The six relative degrees of freedom thus obtained therefore allow a physiological movement of the axis of rotation of the ankle, which can move in space and vary its inclination. In this way Tortesi will not alter the natural movements of the joint, but will limit them within defined amplitudes.

The amplitudes granted to the different natural movements, excluding the flexion and extension movement, can be determined and modified simply by defining the values of the length and external diameter of the spacer 6 that will be inserted in each joint 10. In this way it will be possible, for example, to allow only the flexion-extension movement around the natural MHA of the subject, inserting in each joint 10 a spacer 6 having an external diameter equal to that of the hole 50 and a length equal to the thickness of the second external plate 5; or the therapist will have the possibility to decide the amplitude of the inversion-eversion and abduction-adduction movements simply by inserting in each of the joints 10 a spacer 6 with a defined external diameter and length.

In a possible industrial application of the orthosis, it will be possible to easily define the values of the dimensional differences between the parts of the joint 10 coupled in relative motion, i.e. the external diameter of the spacer 6 with respect to the diameter of the hole 50, as well as the length of the spacer 6 with respect to to the thickness of the plate 5, once the values of the amplitudes of the desired natural movements have been established.

Preferably the first internal plate 4, the second external plate 5 and the threaded counter plate 7 are made or coated in low friction material.

Referring to Figs. 7 and 8, a first alternative embodiment of articulated orthosis V according to the present invention is illustrated.

In addition to the essential construction elements (a first hull 2 'to be associated with a foot 20'; a second hull 3 'to be associated with a leg 30'; a pair of joints 10 'each comprising, in turn, a first internal plate 4 ', a second outer plate 5' equipped with a hole 50 ', a spacer 6', a threaded counter-plate 7 'and a connecting pin 8' integral with said first inner plate 4 ', which are similar to those illustrated in with reference to the general embodiment of the invention and which therefore, for the sake of brevity, will not be described again in detail), the joint 10 'of the articulated orthosis 1' further comprises a third plate arranged between the second shell 3 'and the second outer plate 5 ', to adjust the positioning of the hole 50' with respect to the second hull 3 ', by means of a horizontal and a vertical translation in the sagittal plane.

In particular, the third plate 9 'has a rectangular shape and is equipped with a groove 90', also rectangular, which allows the plate 9 'to be fixed in different positions with respect to the hull 3' by means of a pair of screws 91 '; it is evident that other shapes of the third plate 9 'and of the groove 90' which are suitable for the purpose can also be chosen. Furthermore, the external plate 5 'has a groove 51' which allows the plate 5 'to be fixed in different positions with respect to the plate 9' by means of a pair of screws 52 '; it is evident that different shapes of the plate 5 'and of the groove 51' suitable for the purpose can be chosen.

Furthermore, the joint 10 'of the articulated orthosis Γ comprises, in turn, a fourth plate 14', such as to allow the adjustment of the position of the connecting pin 8 'with respect to the first hull 2', by means of a horizontal and a vertical translation in the plane. sagittal. The fourth plate 14 'has a rectangular shape and is also equipped with two grooves 141' and 142 'in which the pin 8' and a further pair of adjustment screws 143 'can move respectively.

With reference to Fig. 9A, a first variant of the joint 10 "of the articulated orthosis according to the present invention is illustrated.

The joint 10 "also comprises first transversal viscoelastic elements 11", arranged between the first internal plate 4 "and the second external plate 5" and / or between the second external plate 5 "and the threaded counter-plate 7", for precisely control, through the stiffness and damping characteristics of the material constituting the first visco-elastic elements, the mobility of the joint 10 "allowed in the axial direction by the reciprocal axial clearance between the first internal plate 4" and the second plate 5 "and / or the second plate 5" and the threaded counter-plate 7 ".

With reference to Fig. 9B, a second variant of the joint 10 "'of the articulated orthosis according to the present invention is illustrated.

The joint 10 "'comprises, in addition or as an alternative to the first transverse visco-elastic elements 11", second axial visco-elastic elements 13' ", arranged between the spacer 6" 'and the second external plate 5' ", to control in a precisely determined manner, through the stiffness and damping characteristics of the material constituting the second viscoelastic elements, the mobility of the joint 10 '"allowed in the sagittal plane by the reciprocal radial clearance between the hole 50"' of the second outer plate 5 '"and the spacer 6"'. The first 11 "and the second 13 '" viscoelastic elements are provided in such quantity and quality to adjust in the desired way the reciprocal play of the elements between which they are placed; for example the first 11 "and the second 13 '" elastic elements can be elastic washers, cup springs, elastomers and the like having defined stiffness values.

The articulated orthosis 1,1 'according to the present invention, in any of the embodiments and variants described above, has the diameter of the spacer 6, 6', 6 ", 6 '" less than the diameter of the hole 50, 50', 50 ", 50 '" of the second outer plate 5, 5', 5 ", 5 '"; the difference between the diameter of the spacer 6, 6 ', 6 ", 6'" and the diameter of the hole 50, 50 ', 50 ", 50'" of the second external plate 5, 5 ', 5 ", 5'" determines the amplitude of relative translational movements in the sagittal plane.

The articulated orthosis 1,1 'according to the present invention, in any of the embodiments and variants described above, has the length of the spacer 6, 6', 6 ", 6 '" greater than the thickness of the second outer plate 5, 5 ', 5 ", 5'", so that this difference determines the amplitude of the relative angular movements in the frontal and transverse planes and of the relative translational movement in the medio-lateral direction.

The articulated orthosis with floating axis of rotation according to the present invention, illustrated here in the preferred and advantageous embodiment for foot-ankle, can also be applied to a knee or an elbow; in general, Tortesi articulated with floating axis of rotation according to the present invention finds multiple areas of application, which are the direct consequence of the innovative characteristics and advantages set out above, for the treatment and cure of injuries to the musculoskeletal or neurological foot-ankle system such as, for example, post-traumatic treatment of ligament injuries, chronic ankle instability, postoperative or conservative joint support, foot drop or foot pendant due to neuromuscular deficit associated with paralysis, muscular dystrophy, myelomeningocele or as a result of other neurological injuries central or peripheral, central or peripheral paralysis with equine foot attitude, etc. or in any case for any need for adjustable dynamic support.

As can be deduced from the above, the innovative technical solution described here has the following advantageous characteristics:

thanks to the realization of a floating joint that adapts the movement of the orthosis to the natural one of the ankle together with the positioning of the rotation axis of the orthosis coinciding with the ideal ankle tax, a unique possibility compared to the current state of the art, to reproduce the natural movement in the user's ankle, guaranteeing the most physiological behavior possible, compatibly with the constraints and restrictions of the joint movement for which Tortesi is used;

- possibility, unique with respect to the current state of the art, to achieve six relative degrees of freedom between the two hulls, three in the sagittal anatomical plane, one in the frontal anatomical plane, one in the transverse anatomical plane and one in the mid-lateral direction;

thanks to the realization of a modular joint that always uses the same basic elements and optionally the additional elements, all standardized, possibility of being adapted to any user and customized according to his specific needs and also, for each user, to the different phases of the treatment motor protection and rehabilitation;

achievement of greater efficacy from the therapeutic rehabilitation point of view;

excellent user comfort combined with significant pain relief; ease of adjustment;

- high durability, light weight and low friction; And

simple and low-cost series construction, also thanks to the possible use of 3D printing technology.

From the above description it is therefore evident how articulated Tortesi and the methods described allow to achieve the proposed aims.

It is equally evident to a person skilled in the art that it is possible to make modifications and variations to the solution described with reference to the attached figures, without thereby departing from the teaching of the present invention and from the scope of protection as defined by the attached claims.

Quotes:

[1] Alam M, Choudhury IA, Bin Mamat A. Mechanism and design analysis of articulated ankle foot orthoses for drop-foot. ScientificWorldJoumal.

2014; 2014: 867869

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[4] Lundberg, A., Svensson, O., Nemeth, G., Selvik, G., 1989. The axes of rotation of the ankle joint. Journal of Bone and Joint Surgery [British] 71-B, 94-99

[5] Siegler, S., Chen, J., Schneck, C., 1988. The three-dimensional kinematics and flexibility characteristics of the human ankle and subtalar joints. Part 1: kinematics. Journal of Biomechanical Engineering 110, 364-373

[6] Leardini A, O'Connor JJ, Catani F, Giannini S. A geometrie model of the human ankle joint. J Biomech. 1999 Jun; 32 (6): 585-91

[7] Demarais DM1, Bachschmidt RA, Harris GF. The instantaneous axis of rotation (LAOR) of the foot and ankle: a self-determining System with implications for rehabilitation medicine application. IEEE Trans Neural Syst Rehabil Eng. 2002 Dec; 10 (4): 232-8.

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Claims (10)

CLAIMS 1. Articulated orthosis (1,1 ') comprising - a first hull (2.2 ') to be associated with a foot (20.20'), - a second hull (3,3 ') to be associated with a leg (30,30'), e - a pair of joints (10, 10 ', 10 ", 10'") characterized in that each joint (10, 10 ', 10 ", 10'") comprises a first internal plate (4, 4 ', 4 ", 4'") integral with said first hull (2,2 ') on the opposite side to said foot (20,20'), - a second external plate (5, 5 ', 5 ", 5'") integral with said second hull (3,3 ') on the opposite side to said leg (30,30') and equipped with a hole (50, 50 ', 50 ", 50'"), - a spacer (6, 6 ', 6 ", 6'"), - a threaded counter-plate (7, 7 ', 7 ”, 7'"), e - a connecting pin (8, 8 ', 8 ", 8'") integral with said first internal plate (4, 4 ', 4 ", 4'") and whose head abuts on said first hull (2 , 2 ') on the opposite side to said first inner plate (4, 4', 4 ", 4 '"), wherein said hole (50, 50 ', 50 ", 50'") of said second outer plate (5, 5 ', 5 ", 5'") has a larger diameter than the diameter of said spacer (6, 6 ' , 6 ", 6 '") to obtain a reciprocal radial clearance, and in which said spacer (6, 6 ', 6 ", 6'") passes through said hole (50, 50 ', 50 ", 50'") of said second outer plate (5, 5 ', 5 ", 5' ") and is arranged in contact with said first internal plate (4, 4 ', 4", 4' ") and with said threaded counter-plate (7, 7 ', 7", 7' "), and in which the distance between the outer surface (40) of said first inner plate (4, 4 ', 4 ", 4'") and the inner surface (70) of said threaded counter-plate (7, 7 ', 7 ", 7 '") is determined by the length of said spacer (6, 6', 6 ", 6 '") and is greater than the thickness of said second outer plate (5, 5', 5 ", 5 '") for obtain mutual axial play, so that said pair of joints (10, 10 ', 10 ", 10'") has the axes of said connection pins (8, 8 ', 8 ", 8'") aligned with each other and allows said first hull (2, 2 ') and to said second hull (3, 3') a movement relative to six degrees of freedom consisting of two independent translations in the sagittal plane, a translation in the medio-lateral direction, a rotation in the sagittal plane with respect to an axis medium-lateral, a rotation in the frontal plane with respect to an anteroposterior axis and a rotation in the transverse plane with respect to a longitudinal axis, so that the rotation axis of said pair of joints (10, 10 ', 10 ", 10'") is floating around the anatomical center of the joint of a user and said articulated orthosis (Ι, Γ) supports the natural kinematics of the joint of said user. 2. Articulated orthosis (Γ) according to claim 1, wherein said joint (10 ') further comprises a third plate (9'), arranged between said second shell (3 ') and said second outer plate (5'), for adjust the positioning of said hole (50, 50 ', 50 ", 50'") with respect to said second hull (3 '), by means of a horizontal translation and a vertical translation in the sagittal plane. Articulated orthosis (Γ) according to claim 1 or 2, wherein said joint (10 ') further comprises a fourth plate (14'), arranged between said first shell (2 ') and said second outer plate (5') , to adjust the positioning of said connecting pin (8 ') with respect to said first hull (2'), by means of a horizontal translation and a vertical translation in the sagittal plane. 4. Articulated orthosis (1,1 ') according to any one of the preceding claims, in which said spacer (6,6') inserted in each of said joints (10,10 ') has a length and an external diameter such as to reduce or completely cancel the abduction-adduction and inversion-eversion movements granted to the two hulls by said pair of joints (10,10 '). 5. Articulated orthosis (1,1 ') according to any one of the preceding claims, wherein said joint (10 ") further comprises first viscoelastic elements (11"), arranged between said first internal plate (4 ") and said second external plate (5 ") and / or between said second external plate (5") and said threaded counter-plate (7 "), to control in a determined manner with precision, through the characteristics of stiffness and damping of the material constituting said first viscoelastic elements (11 "), the mobility of said joint (10") allowed in the axial direction by said mutual axial clearance between said first internal plate (4 ") and said second external plate (5") and / or said second external plate (5 ") and said threaded counter-plate (7"). 6. Articulated orthosis (1,1 ') according to any one of the preceding claims, wherein said joint (10' ") further comprises second viscoelastic elements (13 <,,,>) / arranged between said spacer (6" ' ) and said second external plate (5 <,,,>) / to precisely control, through the characteristics of stiffness and damping of the material constituting said second viscoelastic elements (13 '"), the mobility of said joint ( TO '") allowed in the sagittal plane by said reciprocal radial clearance between said hole (50, 50', 50", 50 '") of said second external plate (5, 5', 5", 5 '") and said spacer (6.6 <,>, 6 <,,>, 6 <,,,>). 7. Articulated orthosis (1,1 ') according to any one of the preceding claims, in which said first viscoelastic elements (11 ") and said second viscoelastic elements (13'") are elastic washers, cup springs, elastomers and the like having defined stiffness values. 8. Articulated orthosis (1,1 ') according to any one of the preceding claims, in which said hole (50,50 <,>, 50 <,,>, 50 <,,,>) has an elliptical shape and has a radial clearance with respect to said spacer (6,6 <,>, 6 <,,>, 6 <,,,>) / so that, on the sagittal plane, the reciprocal translation between said second outer plate (5,5 <,>, 5 <,,>, 5 <,,,>) and said first inner plate (4, 4 ', 4 ", 4'") has different amplitudes in different directions. 9. Articulated orthosis (1,1 ') according to any one of the preceding claims, wherein said connecting pin (8, 8', 8 ", 8 '") has a thread of larger diameter on the end onto which said first plate is screwed internal (4, 4 ', 4 ", 4'") near the head of said connecting pin (8, 8 ', 8 ", 8'") and a smaller diameter thread on the end on which said threaded counter-plate (7, 7 ', 7 ", 7") opposite the head of said connecting pin (8, 8', 8 ", 8 '"), so as to impose a defined distance between the external surface ( 40) of said first internal plate (4, 4 ', 4 ", 4'") and the internal surface (70) of said threaded counterplate (7, 7 ', 7 ", 7'"), thus fulfilling both the function of the pin (8, 8 ', 8 ", 8'") and that of the spacer (6, 6 ', 6 ", 6'"). 10. Articulated orthosis (1,1 ') according to any one of the preceding claims, in which said first shell (2,2') and said second shell (3,3 ') are made of thermoplastic material, are padded with polyurethane sponge and they are reinforced in the areas near the joints, and in which said first shell (2,2 ') is equipped with an anti-slip sole and in which said second shell (3,3') is equipped with closing means.