GB2478271A

GB2478271A - Dorsiflexion recreation device comprising a pressure sensor and control module

Info

Publication number: GB2478271A
Application number: GB0922584A
Authority: GB
Inventors: Eran Werner
Original assignee: MAGIC MEDICAL Ltd
Current assignee: MAGIC MEDICAL Ltd
Priority date: 2009-12-29
Filing date: 2009-12-29
Publication date: 2011-09-07
Also published as: WO2011080705A1; GB0922584D0

Abstract

A dorsiflexion restoration device includes a harness, connected to the foot and having at least one terminal portion 98 and a retraction mechanism 80 having at least one retraction point, the terminal portion 98 being drawn to the retraction point on the retraction mechanism 101. A manchette affixes the retraction mechanism 80 to the lower leg, or crus. At least one pressure sensor continuously collects information and sends it to a control module. At predetermined stage/s of the pedometric cycle, the retraction mechanism 80 performs a retracting action 94 and applies a tensile force to the terminal portion 98 of the harness, causing dorsiflexion. At other stages, the retraction mechanism 80 is released, allowing plantarflexion of the foot. The retraction mechanism may include a reel, sprocket 84, 90, conveying belt 86 and a motor 82. The control module optionally includes an electroactive polymer.

Description

DORSIFLEXION RECREATION SYSTEMS AND METHODS

TECHNICAL FIELD

[001] The present invention generally relates to orthopedic systems and methods. In particular, the invention relates to a method and mechanical or electromechanical device for physically facilitating foot dorsiflexion; thereby preventing a foot drop effect thus providing for rehabilitation from steppage gait abnormalities.

BACKGROUND ART

[002] The US patents Ser. Nos. 3916886, 4329982, 4817589, 5259834, 6361517, 6602217, 7125392, 7458950 and US applications Ser. Nos. 2003/0073938 and 2005/0010265 are believed to represent the current sate of the art.

SUMMARY OF THE INVENTION

[003] There is provided in accordance with embodiments of the present invention a method and mechanical or electromechanical device for physically facilitating foot dorsiflexion.

[004] The dorsiflexion recreation device of the present invention is useful for preventing a foot drop effect thus providing for rehabilitation from steppage gait abnormalities.

[005] Definitions: The following terms used throughout the specification are defined as: Stance -The period in the gate cycle when the foot is in contact with the floor; Swing -The period in the gate cycle when the foot is not in contact with the floor; Dorsiflexion -Movement of the foot towards the anterior surface of the tibia while bending the ankle; Plantarflexion -Movement of the foot away from the anterior surface of the tibia, straightening the ankle joint; Zero angle -position of the foot in perpendicular to the crus.

[006] It should be understood, however, that the definitions hereinabove are not intended to limit the invention to the particular terms, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[007] The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the appended drawings in which: Fig. 1 is a schematic geometrical diagram showing the vectors of force exerted by the dorsiflexion recreation device of the invention and the dynamics of their action on the human feet; Fig. 2 is a schematic diagram of the abscissa plane, showing the preferred sites for the disposing the sensor and the strap of the harness adjoining the abscissa plane; Figs 3A to 3E are perspective views of various embodiments of the harness of the dorsiflexion recreation device of the invention; Fig. 4 is an isometric view of an embodiment of the retraction mechanism the dorsiflexion recreation device of the invention; Figs 5A and 5B are isometric views of another embodiment of a double-action retraction mechanism the dorsiflexion recreation device of the invention; Fig. 5 is an isometric view of a preferred embodiment of the retraction mechanism employing electro-active polymer.

[008] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention.

DISCLOSURE OF THE INVENTION

[009] Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers! specific goals, such as compliance with technology-or business-related constraints, which may vary from one implementation to another. Moreover, it will be appreciated that the effort of such a development might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of

this disclosure.

[010] The dorsiflexion recreation device (hereinafter DRD) of the invention comprises a mechanical retraction mechanism, harness and manchette. The retraction mechanism typically includes a portable energy source, e.g. electrical battery, and a control module. The control module can be any computing means known in the art. The harness is used to convey the action of the retraction mechanism to the feet or a sole or insole implemented therewith. The manchette is used to affix the DRD and particularly the retraction mechanism thereof, preferably to the posterior portion of the crus.

[011] To illustrate the general geometry of the vectors of force exerted by the retraction mechanism of the dorsiflexion recreation device (hereinafter DRD) of the invention and the dynamics of their action on the human feet, reference is now made to Fig. 1. A plane is herby defined by the abscissa (X-axis) and the ordinate (Y-axis) essentially in parallel to the sagittal plane of crus 10. Abscissa represents a side-view of a plane (hereinafter abscissa plane) tangent to the bottom face of feet 12, essentially paralleling the transverse plane. It should be acknowledged that in implementation of the DRD an insole or sole may be employed, wherein abscissa plane is more correctly to represent the plane tangent to the bottom face of such sole or insole (not shown); however for the sake of simplicity merely the ideal implementation of the DRD on feet 12 is shown in Fig. 1, while those of ordinary skill in the art shall be able to make the proper implementation-specific adjustments. Ordinate represents the position of the retraction point of the retraction mechanism of the DRD, in perpendicular to abscissa, as will be elaborated infra. The retraction point is typically positioned on the ordinate within the range of 150mm to 31 0mm from the origin and preferably approximately at 230mm above the abscissa plane.

The marks 150 and 310 represent the preferable range and the mark 230 represents the preferred position of the retraction point on the ordinate.

[012] Axis A represents the extremum counterclockwise angular translation of the abscissa relatively to the ordinate, at the maximal dorsiflexion angle a, whereas axis B represents the extremum clockwise angular translation of the abscissa relatively to the ordinate, at the maximal plantarilexion angle 13.

Angle a equals approximately 10 to 15 degrees, while angle 13 equals approximately 20 degrees. Arc 14 represents the trajectory of the attachment point of the harness (not shown) of DRD to feet 12 or mutatis mutandis to sole or insole (not shown). Lines 16 and 18 represent the direction of the extrema vectors of force exerted by the DRD on to the harness (not shown) and vice versa. Distances 16 and 18, respectively, represent the closest and the most distanced positions of the attachment point of the harness during the operation of DRD.

[013] The operation of the DRD is synchronized with dynamics of the steppage gait by means of at least one primary sensor. The primary sensor, inter alia, can be attached to the feet, embedded in the insole or sole or disposed within a strap of the harness adjoining the abscissa plane. Referring now to Fig. 2, which is a schematic view of the abscissa plane, showing the preferred sites for the disposing the sensor and the strap of the harness adjoining the abscissa plane. The X-axis represents the lateral dimensions of the aforementioned sites across the width of feet 20, whereas the Y-axis represents the longitudinal dimensions along the length of feet 20.

[014] Primary sensor 21 is a pressure sensor, deployed at predetermined locations under feet 20 to collect data reflecting the change in the pressure exerted over the abscissa plane; thereby providing information regarding the dynamics of the steppage gait. Primary sensor 21 is preferably positioned between longitudinal marks 22 and 24 along the Y-axis. Sensor 21 is typically disposed at the most apical portion of the metatarsal area. Mark 22 is located at about 98 percent of the total length of feet 20. Mark 24 is located at about 58 percent of the total length of feet 20. Sensor 21 is preferably positioned between lateral marks 30 and 32 along the X-axis. Mark 30 is located at about 6 percent of the total width of feet 20, whereas mark 32 is located at about 94 percent of the total width of feet 20.

[015] In some embodiments sensor 21 is a multi-site pressure sensor, comprising an array of individual pressure sensors deployed across an area. In other embodiments, the primary sensor is a two-dimensional surficial resolution pressure sensor able to provide data reflecting gradual change in the pressure exerted across the surface area of the sensor.

[016] The primary sensor collects the data reflecting the changes in the pressure exerted across the area of abscissa plane and transmits these data to the control module of the DRD. In some embodiments one or more wires can be embedded in or interwoven with the harness, whereas in other embodiments a wireless communication link, well-known in the art, can be employed to transmit the aforementioned data; instances of the latter can be found in the electronic orthosis device with an integrated stimulation unit and electrode, available from Orthomedics, at 8610 West Dodge Rd. Omaha, NE 68114, USA, and commercialized under the tradename of Ness L300 -Functional Electrical Stim For Foot Drop.

[017] Optionally an additional secondary sensor (not shown) is employed to provide more comprehensive information regarding the dynamics of the steppage gait. The secondary sensor (not shown) is typically disposed at the most apical portion of the tarsal area. The additional sensor is located between about 24 percent and about 6 percent of the total length of feet 20. The additional sensor is located between about 20 percent and about 80 percent of the total width of feet 20.

[018] The strap (not shown) of the harness adjoining the abscissa plane is preferably positioned between longitudinal marks 26 and 28 along the Y-axis.

Mark 26 is located at about 70 percent of the total length of feet 20, whereas mark 28 is located at about 40 percent of the total length of feet 20.

[019] Referring now to Figs 3A to 3E, which are schematic representations of some embodiments of the harness of the DRD of the present invention. The harness shown in Fig. 3A applied to crus 40 and feet 42 comprises cuff 45 circumfering the medial arch of the feet typically at the metatarsal and/or transverse arch area. Cuff 45 comprises two flanking straps 47, which are drawn to the retraction point (not shown) of the DRD, at the posterior portion of crus 40.

[020] The harness shown in Fig. 3B applied to crus 40 and feet 42 comprises cuff 50 circumfering the medial arch of the feet typically at the metatarsal and/or transverse arch area. Cuff 50 comprises two intercrossing straps 52, which are drawn to the retraction point (not shown) of the DRD, at the posterior portion of crus 40.

[021] The harness shown in Fig. 3C applied to crus 40 and feet 42 comprises cuff 55 circumfering the medial arch of the feet typically at the metatarsal and/or transverse arch area. Cuff 55 comprises primary strap 57.

Primary strap 57 further comprises two bifurcating straps 59, which are drawn to the retraction point (not shown) of the DRD, at the posterior portion of the crus 40.

[022] The harness shown in Fig. 3D applied to crus 40 and feet 42 comprises two intercrossing straps 60, which threaded below the feet, into or onto the sole or insole (not shown). lntercrossing straps 60 may be connected or affixed to the sole or insole (not shown) at the flanks thereof. Straps 60 are drawn to the retraction point (not shown) of the DRD, at the posterior portion of crus 40.

[023] The harness shown in Fig. 3E applied to crus 40 and feet 42 comprises two flanking straps 62, which threaded below the feet, into or onto the sole or insole (not shown). Straps 62 may be connected or affixed to the sole or insole (not shown) at the flanks thereof. Straps 62 are drawn to the retraction point (not shown) of the DRD, at the posterior portion of crus 40.

[024] The embodiments of the harness of the DRD shown Figs 3A to 3E are particularly adapted to the embodiments of DRD affixed at the posterior portion of the crus. It should be acknowledged, however, that various other embodiments adapted to the embodiments of DRD affixed at the anterior portion of the crus and elsewhere are provided within the scope of the present invention, as will be elaborated infra.

[025] Referring now to Fig. 4, which is an isometric view of exemplary retraction mechanism 80 of the DRD of the present invention. Retraction mechanism 80 comprises structural framework 81. Electrical motor 82 is mounted onto structural framework 81. Motor 82 is preferably capable of performing from about 2000 to about 7000 revolutions per minute (RPM) and producing a substantial rotational torque. The rotor of motor 82 is operationally coupled to the driving shaft ending with sprocket 84. Conveying belt 86 couples the rotation of the driving shaft ending with sprocket 84 to driven shaft 89 ending with sprocket 90. Tensioner assembly 92 may be employed to continuously facilitate tension of belt 86; thereby effectively coupling the rotation of the driving shaft ending with sprocket 84 to driven shaft 89 ending with sprocket 90. Driven shaft 89 is furnished with a screw threading (not shown); whereas harness retracting/releasing element 94 is furnished with a matching screw threading (not shown).

[026] The helical pitch of the screw threading furnishing driven shaft 89 and harness retracting/releasing element 94 is preferably from about 0.4 to about 1.2 millimeter (mm) per rotation. Retracting/releasing element 94 is threaded onto pivot 96, disposed coaxially to shaft 89; thereby upon rotation of shaft 89 element 94 performers axial translation about pivot 96, in accordance with the parameters of such rotation, i.e. direction and RPM, and the parameters of the helical pitch of the screw threading furnishing driven shaft 89 and harness retracting/releasing element 94.

[027] Upon axial translation of element 94 about pivot 96, the retraction/release of terminal portion 98 of the strap is accomplished. Aperture in structural framework 81, is to be considered as an exemplary retraction point denoted hereinabove.

[028] In some embodiments the retraction point is not affixed but rather translated along the crus. The retraction mechanism of the embodiments in which the retraction point translated along the crus, are typically comprise a rod protruding from the mechanism and protracted/retracted respectively from/into the mechanism. The terminal portions of the harness are connected to the rod and each time the rod is protracted/retracted, the retraction point is translated along the crus; thereby retracting/releasing the harness.

[029] In some preferred embodiments the DRD comprises two or more retraction mechanisms respectively forming two or more retraction points, each of which retracts/releases a different terminal portion of the harness; wherein each terminal portion of the harness is affected by the respective retraction mechanism independently. In some other embodiments the DRD comprises a double or twofold retraction mechanism respectively forming two retraction points; wherein two different terminal portions of the harness are affected by the same retraction mechanism simultaneously. The double or twofold retraction mechanism may employ pulleys or alike to facilitate a premeditated displasment of the harness relatively to the mechanism. These types of retraction mechanisms are particularly adapted for the types of harnesses comprising more than one terminal portion, as will be elaborated infra.

[030] In some preferred embodiments the retraction mechanism comprises a reel or a couple of reels coaxially affixed to a driven shaft. To exemplify a reels-employing mechanism, reference is now made to Figs 5 A-B, showing retraction mechanism 101 in accordance with some embodiments of the DRD of the present invention. Retraction mechanism 101 comprises structural platform 102 characterized by concave surface 102A and slot 103. Structural platform 102 is designed to be appended to the posterior portion of the crus (not shown), so that concave surface 102A conforms to the convex surface of the crus and slot 103 accommodates the Achilles tendon. Platform 102 is covered by housing 104 enclosing the components of mechanism 101.

[031] Retraction mechanism 101 further comprises motor 105 mounted onto platform 102. The rotor of motor 105 terminates with sprocket 107. Sprocket 107 rotationally coupled via conveying belt 107 to sprocket 108. Sprocket 108 is coupled to driven shaft 109, which is flanked by reels 112 and 114.

[032] Upon rotation of driven shaft 107 terminal portions 116 and 117 of the harness got wound/unwound onto/from the reel/s 112 and 114, respectively, via retraction points 118 and 119; thereby retracting/releasing the harness.

[033] The retraction mechanism shall be able to apply a force of at least 22 Newton and induce a torque of at least 1 Newton per meter. The retraction mechanism should be able to perform a displacement of about at least 25 millimeters. The minimal capacity of the battery is preferably of about 23 kJoul, which shall suffice for 10,000 assuming that not more than 50 percent of the battery's energy will be utilized.

[034] DRD retraction mechanism is affixed by the means of a manchette (not shown) preferably to the posterior portion of the crus. The manchette encircles the crus above ankle, preferably ergonomically conforming therewith.

Examples of a similar manchette can be found in the electronic orthosis housing with an integrated stimulation unit and electrode, available from Orthomedics, at 8610 West Dodge Rd. Omaha, NE 68114, USA, and commercialized under the tradename of Ness L300 -Functional Electrical Stim For Foot Drop. The manchette is preferably encircles the crus above the lateral prominences of the ankle rather tightly; thereby effectively precluding the movement of the retraction mechanism inferiorly during the operation of DRD.

[035] In some preferred embodiments the retraction mechanism is affixed by the manchette to the posterior portion of the crus while positioned below the retraction point; whereas in other embodiments the retraction mechanism is affixed by the manchette to the posterior portion of the crus while positioned above the retraction point. Thus retraction mechanism 80 shown in Fig. 4 is preferably affixed by the manchette to the posterior portion of the crus 10 shown in Fig. 1, at the inclination of the calf beneath the prominence formed by the gastrocnemius, while the retraction point formed at aperture 100 is located on the top face of mechanism 80.

[036] In some embodiments the retraction mechanism is affixed by the manchette to the anterior portion of the crus, positioned typically above the retraction point. -11 -

[037] It should be acknowledged that the embodiments of the harness shown in Figs 3A to 3E may be subject to modifications so as to accommodate a particular positioning, orientation and/or type of the retraction mechanisms and/or retraction point/s thereof. Thus in some embodiments, the harness comprises two different straps drawn to the retraction mechanism, whereby the terminal portions thereof are each independently retracted/released by the retraction mechanism of the DRD. Examples of such straps include flanking straps 47, intercrossing straps 52, bifurcating straps 59, intercrossing straps 60 and flanking straps 62 shown in Figs 3A to 3E.

[038] In other embodiments, the harness comprises a single strap drawn to the retraction mechanism, merely the terminal portion of which, such as terminal portion 98 shown in Fig. 4, is retracted/released by the retraction mechanism of the DRD. Such straps can be formed by joining of two different straps, such as flanking straps 47, intercrossing straps 52, bifurcating straps 59, intercrossing straps 60 and flanking straps 62 shown in Figs 3A to 3E, the joined/unified terminal portion of which is retracted/released by the retraction mechanism of the DRD.

[039] In yet some other embodiments, the harness comprises merely a single strap drawn to the retraction mechanism, the terminal portion of which is retracted/released by the retraction mechanism of the DRD. Example of such single strap harness include a modified harness shown in Fig. 3C, comprising merely cuff 55 and primary strap 57, which is drawn to the retraction point (not shown) of the DRD, at the anterior portion of crus 40.

[040] In some embodiments, the harness comprises a tension sensor (not shown) providing data regarding the tensile force applied to the harness in a given time. The tension sensor may be embedded in a strap of the harness or otherwise form a part thereof.

[041] The strength of the force applied by the retraction mechanism during operation of the DRD and the energy consumed are summarized in Table No. 1: Energy [Joul] Force [N] Angle Range Stage No. N/A N/A 0 Initial Contact 1 0.073 0.6 0 -7 0 Loading 2 Response 0.0 0.0 0 1 0 Mid Stance 3 0.0 0.0 1 0 -20 Terminal Stance 4 N/A N/A N/A Pre-Swing 5 0.1040 0.6 N/A Initial Swing 6 0.104 0.6 -20 0 Mid Swing 7 0.020 0.6 N/A Terminal Swing 8

Table No. 1

Operation of the DRD [042] An average pedometric pace of a human is 110 steps per minute. This results with 55 walking cycles per leg. The dorsiflexion is typically to be facilitated during 14 percent of each walking cycle of each leg. At average pedometric pace the dorsiflexion is typically to be facilitated during about 0.15 seconds. The onset timing of dorsiflexion and the duration thereof is to be adjusted in accord with a given pedometric pace and its changes. Primary sensor of the DRD, such as sensor 21 the location of which is depicted in Fig. 2, is able to provide the information about the pedometric pace as well as to indicate the preferred onset timing for dorsiflexion facilitation.

[043] It is noted that the harness is typically subject to some elastic hysteresis and hence the onset the retraction action typically precedes the onset timing of effectively facilitating dorsiflexion. Similarly the offset of the retraction action or the onset of the release action typically precedes the offset timing of effectively facilitating dorsiflexion.

[044] Since the harness is typically characterized by some intrinsic elasticity, the total displacement applied by the retraction mechanism (hereinafter AD) on the terminal portion of the harness, e.g. at the retraction point, is somewhat larger than the effective displacement (hereinafter [AD) resultantly induced at the attachment point of the harness. Referring not to Fig. 1, the fAD can be calculated as the difference between the lengths of distances 16 and 18; whereas the AD can be calculated from the aforementioned difference, provided the parameters of the intrinsic elasticity of the harness. The fAD is typically equals to about 25 millimeters; whereas AD typically ranges between about 30 and 50 millimeters, depending on the intrinsic elasticity parameters of the harness.

[045] At the maximal retraction applied by the retraction mechanism, the attachment point is located at the intersection of arc 14 and axis A; whereby feet 12 assumes the maximal dorsiflexion angle a. At the maximal release of the harness from the retraction mechanism, i.e. no retraction applied, the attachment point may be located at the intersection of arc 14 and axis B; whereby the feet may assum the maximal plantarflexion angle 13.

[046] In some embodiments, the aforementioned tension sensor of the harness provides a real-time data regarding the tensile force applied to the harness and the release of the terminal portion/s of the harness is controlled in accord with the data provided by the tension sensor. Thus the sensor may facilitate release of the harness by the retraction mechanism if the tensile force applied to the harness exceeds a predetermined threshold, for instance during a given stage of the pedo metric cycle.

[047] The activity of the DRD during the pedometric cycle may be characterized in accordance with the Table No. 2:

DRD Description % of cycle Stage No.

Active Foot just touches the floor 0--2% Initial Contact 1 Not Starts with initial floor contact 0--1 0% Loading 2 Active and continues until the other Response foot is lifted for swing Not Starts as the other foot is 1 0--30% Mid Stance 3 Active lifted and continues until weight is aligned over the forefoot Not Begins with the rise of the 30--50% Terminal 4 Active heel and continues until the Stance other foot strikes the ground Not Begins with the initial contact 50--60% Pre-Swing 5 Active of the opposite limb and ends with ipsilateral toe-off Active Begins with the lift of the foot 60--73% Initial Swing 6 from the floor and ends when the swinging foot is opposite the stance foot Active Begins as the swinging limb 73--87% Mid Swing 7 is opposite the stance limb and ends when the swinging limb is forward and the tibia is vertical Active Begins with vertical tibia and 87--1 00% Terminal 8 ends when the foot strikes Swing the floor

Table No. 2

BEST MODE FOR PRACTICING AND CARRYING OUT THE INVENTION

[048] In accordance with some preferred embodiments of the present invention the retraction mechanism comprises an electro-active polymer (hereinafter EAP). The EAP is preferably of a rectangular-parallelepiped or cuboid shape. To exemplify the structure of a retraction mechanism employing EAP, reference is now made to Fig. 6. Retraction mechanism 120 comprises EAP block 122, accommodated in a structural framework housing (not shown), which is affixed by the means of a manchette (not shown) preferably to the posterior portion of the crus. Examples of EAP include materials disclosed by Yoseph Bar-Cohen in Electroactive Polymer (EAP) Actuators as Artificial Muscles: Reality, Potential, and Challenges, at SPIE Press Monograph, Vol. PM98, 2001. EAP block 122 comprises first electrical terminal 124, coupled to electrical conduit 126. Terminal 124 can be formed by a strip of foil-like electrically conductive material, capable of deformation/folding upon contraction/expansion of block 122. EAP block 122 further comprises a second electrical terminal (not shown) disposed on the opposite side thereof and coupled to the respective electrical conduit (not shown).

[049] The bottom face (not shown) of EAP block 122 is affixed to the structural framework housing (not shown), whereas the top face is operationally connected to terminal portion 128 of the harness. It should be acknowledged that additional terminal portions of the harness can be operationally connected to the top face of EAP block 122, for the types of harnesses comprising more than one terminal portion, as will be elaborated infra.

[050] Upon application of an electrical potential difference of a predetermined voltage to the electrical conduits coupled to the respective electrical terminals, EAP block 122 contracts in direction of arrow 130; thereby terminal portion 128 of the harness is retracted downwards. Upon outage of the aforementioned electrical potential difference or a decrement thereof EAP block 122 expands in the direction opposite to arrow 130, inter alia due to the intrinsic bias of the contracted polymeric material of block 122; thereby terminal portion 128 of the harness is released upwards.

[051] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein above; rather the scope of the invention is defined by the claims which follow:

Claims

CLAIMS1. A dorsiflexion recreation device comprises: [a] a harness having at least one terminal portion, wherein a strap of said harness is operationally connected or forming a part of at least one selected from: [1] a feet, [2] an insole and [3] a sole; [b] a retraction mechanism, said retraction mechanism is characterized by at least one retraction point, wherein said at least one terminal portion of said harness is drawn to said at least one retraction point; [c] a manchette, used to affix said retraction mechanism to a crus for the feet of which the recreation of dorsiflexion is to be achieved; [d] at least one pressure sensor disposed at the abscissa plane, said pressure sensor continuously collects an information about the dynamics of the steppage gait, and [e] a control module receiving said information collected by said pressure sensor and controlling the operation of said retraction mechanism; wherein at predetermined stage/s of the pedometric cycle, determined by said control module from said information collected by said pressure sensor, said retraction mechanism performs a retracting action, thereby applying a tensile force to said at least one terminal portion of said harness and actively facilitating a dorsiflexion of said feet, and wherein at other stage/s than said predetermined stage/s of the pedometric cycle, said retraction mechanism performs a releasing action, thereby allowing a plantarflexion of said feet.
2. The dorsiflexion recreation device as in claim 1, wherein said predetermined stage/s of the pedometric cycle is/are selected from the group consisting of: an initial contact, initial swing, mid-swing and terminal swing.
3. The dorsiflexion recreation device as in claim 1, further comprising a portable energy source.
4. The dorsiflexion recreation device as in claim 1, wherein said pressure sensor is a multi-site pressure sensor, comprising an array of individual pressure sensors deployed across an area, or a two-dimensional surficial resolution pressure sensor, able to provide data reflecting gradual change in the pressure exerted across the surface area thereof.
5. The dorsiflexion recreation device as in claim 1, wherein said pressure sensor is attached to said feet, embedded in said insole or said sole, or disposed within said strap of said harness adjoining the abscissa plane.
6. The dorsiflexion recreation device as in claim 1, wherein said pressure sensor is positioned between about 98 percent and about 58 percent from the total length said feet.
7. The dorsiflexion recreation device as in claim 1, wherein said pressure sensor is positioned between about 6 percent and about 94 percent of the total width of said feet.
8. The dorsiflexion recreation device as in claim 1, wherein said data collected by said pressure sensor is transmitted to said control module via at least one wire embedded in or interwoven with said harness, or via a wireless communication link.
9. The dorsiflexion recreation device as in claim 1, further comprising an additional pressure sensor used to provide more comprehensive information regarding said dynamics of said steppage gait.
1O.The dorsiflexion recreation device as in claim 1, wherein said strap of said harness is preferably positioned between about 70 percent and about 40 percent of the total length said feet.
11.The dorsiflexion recreation device as in claim 1, wherein said harness comprises a cuff circumfering the medial arch of said feet and two flanking straps drawn to said at least one retraction point of said mechanism.
12.The dorsiflexion recreation device as in claim 1, wherein said mechanism is affixed by said manchette to the posterior portion of said crus.
13.The dorsiflexion recreation device as in claim 1, wherein said harness comprises a cuff circumfering the medial arch of said feet and intercrossing straps drawn to said at least one retraction point of said mechanism.
14.The dorsiflexion recreation device as in claim 1, wherein said harness comprises a cuff circumfering the medial arch of said feet, a primary strap further comprising two bifurcating straps drawn to said at least one retraction point of said mechanism.
15.The dorsiflexion recreation device as in claim 1, wherein said harness comprises two intercrossing straps operationally connected at attachment points to said feet, said sole or said insole at the flanks thereof and drawn to said at least one retraction point of said mechanism.
1 6. The dorsiflexion recreation device as in claim 1, wherein said harness two flanking straps operationally connected at attachment points to said feet, said sole or said insole at the flanks thereof and drawn to said at least one retraction point of said mechanism.
17.The dorsiflexion recreation device as in claim 1, wherein said retraction mechanism comprises: [a] a structural framework on which the components of said mechanism are mounted; [b] an electrical motor the rotor of which is rotationally coupled to a driving shaft sprocket; [C] a driven shaft furnished with a screw threading and rotationally coupled to a sprocket; [d] a conveying belt coupling the rotation of said sprockets; [e] a pivot disposed coaxially to driven shaft; [f] a harness retracting/releasing element furnished with a screw threading respectively matching said screw threading of said driven shaft, said retracting/releasing element is threaded onto said driven shaft and onto said pivot; wherein upon rotation of said driven shaft said retracting/releasing element performers axial translation along said pivot thereby retracting/releasing said harness.
18.The dorsiflexion recreation device as in claim 1, wherein said retraction mechanism comprises: [a] a structural platform; [b] a motor mounted onto said platform; the rotor of said motor terminates with sprocket [c] a driven shaft comprising a sprocket and at least one reel/s, and [d] a conveying belt rotationally coupling said sprockets; wherein upon rotation of said driven shaft said at least one terminal portion/s of said harness is wound/unwound onto/from said at least one reel/s; thereby retracting/releasing said harness.
19. The dorsiflexion recreation device as in claim 18, wherein said platform is characterized by a concave surface and a slot, wherein said platform is to be appended to the posterior portion of the crus, so that concave said -20 -surface thereof conforms with the convex surface of said crus and said slot accommodates the Achilles tendon.
20.The dorsiflexion recreation device as in claim 1, wherein said retraction mechanism is able to apply a force of at least 22 Newton and induce a torque of at least 1 Newton per meter.
21.The dorsiflexion recreation device as in claim 1, wherein said retraction mechanism is be able to perform a displacement of about at least 25 millimeters.
22.The dorsiflexion recreation device as in claim 1, wherein said portable energy source is characterized by the minimal capacity of about 23,000 Joule.
23.The dorsiflexion recreation device as in claim 1, wherein said retraction mechanism comprises an electro-active polymer.
24.The dorsiflexion recreation device as in claim 1, further comprising a tension sensor providing a real-time data regarding the tensile force applied to said harness.
25. The dorsiflexion recreation device as in claim 24, wherein the release of said at least on terminal portion/s of said harness is allowed whenever the tensile force applied to said harness exceeds a predetermined threshold, for a given stage of the pedometric cycle.