US 2012/0016493 A1 Hansen Et Al

US 201200 16493A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2012/0016493 A1 Hansen et al. (43) Pub. Date: Jan. 19, 2012

(54) PASSIVE ANKLE-FOOT PROSTHESIS AND Publication Classification ORTHOSIS CAPABLE OF AUTOMATIC (51) Int. Cl. ADAPTATION TO SLOPED WALKING A6IF 2/66 (2006.01) SURFACES AND METHOD OF USE (52) U.S. Cl...... 623/50; 623/53 (75) Inventors: Andrew H. Hansen, Apple Valley, (57) ABSTRACT MN (US); Jonathon W. Sensinger, The present invention relates to an improved system for use in Chicago, IL (US) rehabilitation and/or physical therapy for the treatment of injury or disease to the lower limbs or extremities. The system (73) Assignee: Northwestern University, can enable an amputee to proceed over any inclined or Evanston, IL (US) declined Surface without overbalancing. The system is mechanically passive in that it does not utilize motors, force (21) Appl. No.: 13/066,361 generating devices, batteries, or powered sources that may add undesirable weight or mass and that may require recharg (22) Filed: Apr. 12, 2011 ing. In particular the system is self-adapting to adjust the torque moment depending upon the motion, the extent of Related U.S. Application Data inclination, and the Surface topography. An additional advan (60) Provisional application No. 61/342,281, filed on Apr. tage of the improvement is that the system can be light and 12, 2010. may also be simple to manufacture.

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PASSIVE ANKLE-FOOT PROSTHESIS AND from a system whereas stiffness can store and release energy ORTHOSIS CAPABLE OF AUTOMATIC to a system throughout a loading and unloading cycle (that is, ADAPTATION TO SLOPED WALKING a walking cycle). SURFACES AND METHOD OF USE 0006 Recent research has suggested that roll-over shape, the effective rocker shape that the ankle-foot system con forms to between heel contact and opposite heel contact, is an 0001. The present application claims priority to U.S. Pro important characteristic for walking. Hansen ((2002): “Roll visional Patent Application Ser. No. 61/342,281 entitled over Characteristics of Human Walking With Applications for “Improvements to Passive Ankle-Foot Prosthesis Capable of Artificial Limbs.” Ph.D. dissertation, Northwestern Univer Automatic Adaptation to Sloped Walking Surfaces and Meth sity, Evanston, Ill.) found that the able-bodied ankle-foot ods of Use', filed 12 Apr., 2010, which is herein incorporated system adapts to several walking conditions to maintain a by reference in its entirety for all purposes. This application is similar roll-over shape and that its roll-over shape changes also related to International Patent Application Serial No. predictably when walking on inclined or declined Surfaces. PCT/US2007/022208, filed 17 Oct., 2007, U.S. patent appli Specifically, able-bodied ankle-foot systems are capable of cation Ser. No. 12/311,818, filed 13 Apr., 2009, and U.S. automatically adapting to differences in shoe heel height and Provisional patent application Ser. No. 60/852,174, filed 17 to different surface inclinations. Current prosthetic ankle-foot Oct. 2006. mechanisms cannot automatically adapt to these conditions. 0007. The prior art demonstrates that there is a current and 0002 This invention was made with government support long-felt need for an improved ankle prosthesis or ankle-foot under United States Department of Veterans Affairs grant prosthesis or orthosis that can better emulate the gait of an numbers A6567R and A6565R. The United States govern able-bodied individual and adapt to the terrain on the first ment has certain rights in the invention. step.

TECHNICAL FIELD SUMMARY OF THE INVENTION 0003. The inventions relate to improved ankle-foot pros 0008. The invention provides prosthetic and orthotic thetic and orthotic systems and methods of use. In particular ankle-foot systems. The systems can be used by a human the prosthetic or orthotic systems comprise an ankle unit that, Subject as a prosthesis or an orthosis to assist the user's gait in combination with other mechanical elements of prosthetic and to prevent or reduce the likelihood of compromising the or orthotic systems, enable the gait of an individual using the user's balance. device to emulate the gait of able-bodied individual and that 0009. In one embodiment the invention provides a self automatically adapts the gait to different terrains and slopes adapting prosthetic system, the self-adapting prosthetic sys on each and every step. tem comprising a foot shell, an improved passive adaptive ankle-foot prosthesis, and means for attachment to a leg, the BACKGROUND ART ankle foot prosthesis comprising a footplate, an ankle system, the ankle system comprising a housing, a first cam, a second 0004. Many currently available prosthetic and orthotic cam, a bracket, wherein the housing and the bracket are ankle-foot mechanisms do not allow ankle motion. Rigid fixedly attached to the means for attachment to the leg, ankle prosthetic and orthotic ankle-foot devices generally wherein the bracket is fixedly attached to the first cam, attempt to replace the actions of the biologic ankle-foot sys wherein the first cam is in movable contact with a part of the tem through deformations of their materials and/or by utiliz second cam and the first cam and second cam comprise a cam ing rocker shapes on the plantar Surfaces. The prosthetic and clutch system, and wherein the footplate comprises an ante orthotic ankle-foot devices that do incorporate ankle motion riorportion and a posteriorportion and further comprising an usually allow rotational motion about a single point that does essentially horizontal plantar member, a torsion means, and not change without mechanical adjustments of the prosthesis an essentially vertical member, the vertical member being or orthosis. Some of these devices use springs and/or bumpers perpendicular to the horizontal plantar member and opera to store and release energy and return the device's ankle joint tively attached to the posterior portion of the footplate, the to one “equilibrium” point. This single and constant “equi Vertical member further comprising an aperture, the aperture librium” point can result in good function on level terrain and shaped and adapted to confine at least one neutralizing ele when using shoes of one particular heel height (heel and ment and a spacer, the neutralizing element being operatively forefoot sole differential). However, problems can arise when connected to the spacer, wherein the spacer is axially con walking on different terrain or when using shoes of different nected to the housing, wherein the housing is axially con heel height. The heel height problem can be fixed using a nected to the vertical member of the footplate, and wherein change in the alignment of the prosthesis. However, this is not the second cam is axially connected to the vertical member of a simple task and one that does not happen automatically. the footplate and wherein the torsion means is shaped and 0005. A patent issued to Wayne Koniuk (U.S. Pat. No. adapted for confined placement between the second cam and 6,443,993 B1. "Self-Adjusting Prosthetic Ankle Apparatus', the horizontal plantar member, and wherein the improved issued Sep. 3, 2002) discloses a device that will adapt to passive adaptive ankle-foot prosthesis is shaped and adapted various terrains and to shoes of different heel height. How for placement within the foot shell and wherein the foot shell ever, Koniuk's design does not appear to have energy storage comprises, in part, a flexible material. In a preferred embodi and release properties, utilizes more sensing devices than the ment, wherein the torsion means is selected from the group proposed design, and does not appear to give plantarflexion at consisting of a spring, a tunable spring, a clockwork spring, a late stance. Koniuk's design is based on damping control of piston, a damper, a bumper, and an elastomeric material. In the ankle joint whereas the proposed device is based on the another preferred embodiment the neutralizing element and control of stiffness about the ankle. Damping removes energy the cam clutch are in-line. In yet another preferred embodi US 2012/0016493 A1 Jan. 19, 2012

ment, the second cam comprises an external Surface and an In a most preferred embodiment the range of movable contact internal surface. In a more preferred embodiment, the first of the first cam in contact with the second cam is not greater cam is in movable contact with the internal surface of the than 95°. In another most preferred embodiment, the ankle second cam. In a most preferred embodiment the range of system has a plantarflexion-dorsiflexion range of from movable contact of the first cam in contact with the second between 80° plantarflexion to about 45° dorsiflexion. In cam is not greater than 95°. In another most preferred another embodiment the ankle system allows a user to emu embodiment, the ankle system has a plantarflexion-dorsiflex late normal gait. In an alternative embodiment, the ankle ion range of from between 80° plantarflexion to about 45° system allows a user to approximately emulate normal gait. dorsiflexion. In another embodiment the ankle system allows 0012. In another preferred embodiment the self-adapting a user to emulate normal gait. In an alternative embodiment, orthotic system comprises a composition selected from the the ankle system allows a user to approximately emulate group consisting of stainless steel, copper, aluminum, tita normal gait. nium, metal matrix composite, metal alloy, NITINOL, DEL 0010. In another preferred embodiment the self-adapting RIN (acetal), acrylonitrile butadiene styrene (ABS), nylon, prosthetic system comprises a composition selected from the polypropylene, polybromate, polycarbonate, glycolised group consisting of stainless steel, copper, aluminum, tita polyethylene terephthalate (PETg) copolyester, polytet nium, metal matrix composite, metal alloy, NITINOL, DEL RIN (acetal), acrylonitrile butadiene styrene (ABS), nylon, rafluorethylene (PTFE), ePTFE, polypropylene, a polymer, polypropylene, polybromate, polycarbonate, glycolised glass fiber-resin composites, and carbon fiber resin compos polyethylene terephthalate (PETg) copolyester, polytet ites. In an alternative embodiment the self-adapting orthotic rafluorethylene (PTFE), ePTFE, polypropylene, a polymer, system further comprises a foot shell. In a preferred embodi glass fiber-resin composites, and carbon fiber resin compos ment, the means for attachment to an ankle are selected from ites. In an alternative embodiment the self-adapting pros the group consisting of a residual limb Socket, direct skeletal thetic system further comprises a foot shell. In a preferred attachment to the residual limb, a clamshell socket, and a leg embodiment, the means for attachment to a leg are selected cuff. from the group consisting of a residual limb Socket, direct 0013. In another embodiment, the invention provides a skeletal attachment to the residual limb, and a leg cuff. prosthetic or orthotic system for a user to emulate normalgait, 0011. In another embodiment the invention provides a the prosthetic system comprising an ankle member, the ankle self-adapting orthotic system, the self-adapting orthotic sys member comprising a reversible engagement means, a first tem comprising a footplate, an improved passive adaptive torsion means, and a joint, and wherein in use, a torsion curve ankle system, and means for attachment to an ankle, the ankle plot of ankle moment against ankle dorsiflexion angle of the system comprising the footplate, means for attaching to the prosthetic system during a gait cycle comprises at least one means for attachment to an ankle, a housing, a first cam, a transition point, wherein the reversible engagement means is second cam, a bracket, wherein the housing and the bracket operatively connected to the first torsion means, wherein the are fixedly attached to the means for attachment to the ankle, first torsion means is operatively connected to the joint, and wherein the bracket is fixedly attached to the first cam, wherein the joint is operatively connected to the engagement wherein the first cam is in movable contact with a part of the second cam and the first cam and second cam comprise a cam means. In an alternative embodiment, the system allows a clutch system, and wherein the footplate comprises an ante user to approximately emulate normal gait. In a preferred riorportion and a posteriorportion and further comprising an embodiment the system is used by a user to proceed over a essentially horizontal plantar member, a torsion means, and Surface without compromising balance wherein the Surface an essentially vertical member, the vertical member being comprises a plurality of grades or elevations. More preferably perpendicular to the horizontal plantar member and opera the torsion curve plot comprises a plurality of transition tively attached to the posterior portion of the footplate, the points. In one alternative embodiment the transition point of Vertical member further comprising an aperture, the aperture the torsion curve plot is at a negative torque moment. In shaped and adapted to confine at least one neutralizing ele another alternative embodiment the transition point of the ment and a spacer, the neutralizing element being operatively torsion curve plot is at a negative ankle dorsiflexion angle. In connected to the spacer, wherein the spacer is axially con another alternative embodiment the transition point of the nected to the housing, wherein the housing is axially con torsion curve plot is at a positive torque moment. In yet nected to the vertical member of the footplate, and wherein another alternative embodiment the transition point of the the second cam is axially connected to the vertical member of torsion curve plot is at a positive ankle dorsiflexion angle. In the footplate and wherein the torsion means is shaped and a most preferred embodiment the prosthetic system automati adapted for confined placement between the second cam and cally adapts to different Surface conditions. In an alternative the horizontal plantar member, and wherein the improved embodiment the self-adapting prosthetic or orthotic system passive adaptive ankle-foot orthosis is shaped and adapted for further comprises a foot shell placement on at least one side of the biological ankle of the user or individual. In a preferred embodiment, wherein the 0014. In one embodiment the prosthetic system comprises torsion means is selected from the group consisting of a a composition selected from the group consisting of stainless Spring, a tunable spring, a clockwork spring, a piston, a steel, copper, aluminum, titanium, metal matrix composite, damper, a bumper, and an elastomeric material. In another metal alloy, such as NITINOL, DELRIN (acetal), acryloni preferred embodiment the neutralizing element and the cam trile butadiene styrene (ABS), nylon, polypropylene, poly clutch are in-line. In yet another preferred embodiment, the bromate, polycarbonate, glycolised polyethylene terephtha second cam comprises an external Surface and an internal late (PETg) copolyester, polytetrafluorethylene (PTFE), Surface. In a more preferred embodiment, the first cam is in ePTFE, polypropylene, a polymer, glass fiber-resin compos movable contact with the internal surface of the second cam. ites, carbon fiber resin composites, and the like. US 2012/0016493 A1 Jan. 19, 2012

0015. In a more preferred embodiment the equilibrium 0027 FIG. 10 illustrates an exemplary device of the inven point B of the torsion curve plot is calculated using the equa tors’ prior art invention in use. tion 0028 FIG.11 illustrates two stages during operation of the prosthetic ankle-foot system (inventors’ prior art invention) T-k(0-3), showing, in part, the relative positions of the internal gear and where T, torque due to triceps Surae spring(s): 0–ankle dor external gear in use. FIG. 11A shows the device in a loaded Siflexion angle; Bankle angle at the triggertime; and k is the state. FIG. 11B shows the device in an unloaded state. impedance factor. In an alternative more preferred embodi 0029 FIG. 12 illustrates an exploded illustration of an ment the equilibrium point of the torsion curve plot is exemplary device of the inventors’ prior art invention as well calculated using the equation as an exemplary illustration of the device in use. 0030 FIG. 13 illustrates two stages during operation of the prosthetic ankle-foot system (inventors’ prior art invention) where T torque due to neutralizing spring(s): 0–ankle dor showing, in part, the relative positions of the base and the cam Siflexion angle; ankle dorsiflexion bias; and k is the during active motion of the use. FIG. 13A shows the device in impedance factor. In another preferred embodiment the a loaded state. FIG. 13B shows the device in an unloaded method comprises the step of whereina toe-off and the trigger State. time occur in continuous and alternating order. In a more 0031 FIG. 14 through 20 illustrate a sequence of images preferred embodiment the method provides automatic adap of the invention showing how the invention works on inclines tation in the Sagittal plane of the self-adapting ankle-foot and declines. device. In another more preferred embodiment the method provides the self-adapting ankle-foot device that adapts to 0032 FIGS. 21 through 31 illustrates a sequence of three-dimensional changes in terrain. In a most preferred images of the invention showing how the invention works and embodiment the three-dimensional changes in terrain is discloses plots of ankle dorsiflexion/plantarflexion against selected from the group consisting of side slopes, and com time. binations of side and upward sloping Surfaces. 0033 FIG. 32 illustrates a series of experimental data 0016. The ankle-foot devices automatically adapt to vari obtained during testing of a device of the invention on ous walking Surfaces using stiffness-based control and few inclined, level, and declined Surfaces. sensing devices. This mode of control may be preferable to 0034 FIG.33 illustrates a theoretical plot of ankle dorsi damping-based control (Koniuk, 2002) because it allows for flexion/plantarflexion against time for the system or device return of stored energy. In theory, equilibrium-point pros showing the time at when a first minimum dorsiflexion angle thetic ankle-foot devices of the invention are designed to store is reached (1) where the brake, lock, or clutch engages and and return energy with a high degree of efficiency. would remain engaged until a second minimum dorsiflexion angle is reached (2). BRIEF DESCRIPTION OF THE DRAWINGS 0035 FIG. 34 illustrates three phases of ambulatory motion, (A) plantarflexion, (B) neutral, and (C) dorsiflexion, 0017 FIG. 1 illustrates an exemplary embodiment of the showing how each of the elements interact with one another. invention. 0036 FIG.35 illustrates an exemplary embodiment of the 0018 FIG. 2 illustrates a linear braking mechanism exem invention shown wherein the hinge bar and hinge spring are plifying the invention. substituted with an actuator (117). 0019 FIG. 3 illustrates an exemplary loading phase of a 0037 FIG. 36 illustrates an exemplary embodiment of the device of the invention. invention shown when ts=0 and ns=0. 0020 FIG. 4 illustrates an exemplary torsion curve of a 0038 FIGS.37A-O illustrate exemplary sequences of gait pair of neutralizing springs (NS: prior art) showing , the cycles at different NS and TS angle values. point of intersection of the curve at T=0 (the equilibrium 0039 FIGS. 37A-37C: Cain engaged at 10° NS plantar point). flexion. 0-10° TS range shown: FIGS. 37D-37F: Cam 0021 FIG. 5 illustrates an exemplary torsion curve of a engaged at 5° NS plantarflexion. 0-10° TS range shown: “triceps surae spring (TS; part of the instant invention) FIGS. 37G-37I: Cam engaged at 0° NS plantarflexion. 0-10° showing fB, the point of intersection of the curve at T=0 (the TS range shown: FIGS. 37J-37L: Cam engaged at 5° NS equilibrium point). dorsiflexion. 0-10° TS range shown: FIGS. 37M-37O: Cam 0022 FIG. 6 illustrates an exemplary torsion curve of the engaged at 10° NS dorsiflexion. 0-10TS range shown. invention showing that the torsion curve has at least two 0040 FIGS. 38A-E illustrate an exemplary gait cycle with equilibrium points. FIGS. 6A and 6B exemplify the invention 0° TS dorsiflexion and between 10° NS plantarflexion in use up a gradient (slope). through 10° NS dorsiflexion. FIG.38A: NS: 10° plantarflex 0023 FIGS. 6C and 6D exemplify the invention in use on ion, TS: 0°: FIG. 38B: NS: 5° plantarflexion, TS: 0°: FIG. a level surface. FIGS. 6E and 6F exemplify the invention in 38C: NS: 0°, TS: 0°: FIG.38D: NS: 59 dorsiflexion, TS: 0°: use down a gradient (slope or incline/decline). FIGS. 6B, 6D, FIG.38E: NS: 10° dorsiflexion, TS: 0°. and 6F illustrate the predicted curve of the invention in use 0041 FIGS. 39A-E illustrate an exemplary gait cycle with showing the transition point (intersection of the NS curve 5° TS dorsiflexion and between 10° NS plantarflexion with the TS curve. through 10° NS dorsiflexion. FIG. 39A: NS: 10° plantarflex 0024 FIG. 7 illustrates average ankle moment plotted ion, TS:5° dorsiflexion; FIG.39B: NS:5° plantarflexion, TS: against dorsiflexion angle of twenty-four able-bodied sub 5° dorsiflexion; FIG. 39C: NS: 0°, TS: 5° dorsiflexion; FIG. jects. 39D: NS: 5° dorsiflexion, TS: 5 dorsiflexion; FIG. 39E: NS: 0025 FIG. 8 illustrates an equilibrium-point ankle-foot 10° dorsiflexion, TS: 5° dorsiflexion. orthosis (AFO). 0042 FIGS. 40A-E illustrate an exemplary gait cycle with 0026 FIG. 9 an exemplary device of the invention. 10° TS dorsiflexion and between 10° NS plantarflexion US 2012/0016493 A1 Jan. 19, 2012 through 10° NS dorsiflexion. FIG. 40A: NS: 10° plantarflex spring may be located where the corresponding muscle group ion, TS: 10° dorsiflexion; FIG. 40B: NS: 5° plantarflexion, (gastrocnemius and soleus muscles) would be (that is, in or TS: 10° dorsiflexion; FIG. 40C: NS: 0°, TS: 10° dorsiflexion; proximal to the calf region). This larger and considerably FIG. 40D: NS: 5° dorsiflexion, TS: 10° dorsiflexion; FIG. stiffer spring is in series with an engagement means (for 40E: NS: 10° dorsiflexion, TS: 10° dorsiflexion. example, a braking or locking component) as Stated earlier. Preferably, the TS spring and the engagement/disengagement DETAILED DESCRIPTION OF THE INVENTION (braking or locking) mechanism, are in series. In the alterna 0043. The system described herein provides at least three tive, the TS spring/engagement combination and the NS improvements to the inventors’ prior art invention. spring(s) are in parallel. In one embodiment, the engagement 0044) The inventors were under obligation at the time all mechanism may be considered to be a variable damper that the inventors were made to assign the rights to the same Switches between near-Zero damping to extremely high entities. damping values. 0045 (1) A simpler weight activation element: In the 0051. At all times, the neutralizing springs (ns) are acting improvement, the prior art four-bolt telescoping system (see, according to the following equation (k, impedance factor; for example, FIGS. 10 through 13, that illustrate inventors could be a function of 0, the ankle dorsiflexion angle in prior art invention) is substituted by a simple hinge (see FIGS. degrees). This is also an example of the prior art (FIG. 4): 9, and 34 through 40. The resulting system comprising the Tk(0-), simple hinge therefore takes up much less space, is lighter in weight, and is more robust that the prior art. 0052 where 0046 (2) Improved cam assembly: In the improvement, 0.053 T torque due to neutralizing springs the cam assembly is greatly reduced in size by moving the 0054 0=ankle dorsiflexion drive cam inside the main cam. In addition, the knurls have 0055 ankle dorsiflexion bias been omitted that results in quieter operation and a more 0056 Between the “trigger (engagement) time' to toe-off durable system. (the beginning of Swing phase), the triceps Surae spring (ts) is 0047 (3) In-line clutch and neutralizing elements: The also engaged according to the following equation (k, imped neutralizing elements and the cam clutch system (comprising ance factor, could be a function of 0, the ankle dorsiflexion the drive cam and the main cam) are positioned in a fore-aft angle in degrees). This is also an example used to illustrate the arrangement that allows a much thinner outer housing and instant invention (see, for example, FIG. 5): having a reduced overall ankle size and ankle thickness. All of these improvements are of benefit to a user. T-k(0-3), 0048. The equilibrium point prosthetic and orthotic ankle 0057 where foot devices work by utilizing a natural movement of the 0.058 T-torque due to triceps surae spring ankle during early stance phase to adjust the resting length, 0059) 0=ankle dorsiflexion also known as the equilibrium point, of a spring mechanism 0060 f—ankle angle at the trigger time (see, for example, Williams, et al. (2009) J. Biomechan. Engin. 131: DOI: 10.1115/13005335; and PCT/US2007/ 0061 The ankle angle at the trigger time (B) changes for 022208). The devices are named after Feldman's equilibrium different terrain: B increases for uphill terrain causing the point hypothesis (1986) “Once more on the equilibrium curve to shift to the right; B decreases for downhill terrain, point hypothesis (lambda model) for motor control J. Motor causing the curve to shift to the left. Behav. 18: 17-54) regarding the control of human move 0062 For the preferred embodiment, the triggertime is the ments. As used herein, the term “equilibrium point' is the time of foot flat (in early stance phase). It is conceivable that angular position of the ankle system when the net external other trigger times could be used, though, including a time at torques (not including those applied by components within which the pylori reaches a particular orientation in stance the system or in the absence of external forces and moments) phase (for example, near vertical). So the overall torque at the are equal to Zero. ankle (T) can be described as follows: 0049. The premise of the design is the use of two sets of elastic elements, such as a spring or the like, wherein one set Tns; toe-off St Sttrigger dominates the response of the system when an engaging/ T = disengaging mechanism, Such as brake or the like, is engaged Tns + Tis; trigger < t < toe-off and another set that dominates the response when the engag ing/disengaging mechanism is released. Allowing the foot to “find the walking Surface during early stance and then apply 0063) Note that the act of walking is cyclic so the toe-off ing the engaging/disengaging mechanism will allow the and trigger times occur in continuous and alternating order. In device to inherently and automatically adapt to a variety of addition to this, the invention provides not only automatic terrain and/or shoe heel heights. Refer to FIGS. 1-9, 14-30, adaptation in the Sagittal plane, but also envisions devices that 32,34,35,36,37,38, 39, and 40, for drawings illustrating the can adapt to three-dimensional changes in terrain, for embodiment of the invention. example, side slopes, and combinations of side and upward 0050. The device comprises two sets of springs: A set of sloping Surfaces. “neutralizing springs” (NS) and a larger and stiffer “triceps 0064. At the transition point, the system engages and sets Surae spring (TS spring) that is in series with a braking or the equilibrium point of at least one torsional element. This locking component. The “neutralizing springs are config transition Switches the system between a low impedance State ured such that their equilibrium point (point of Zero ankle to a high impedance state. Because the transition point can be moment) is at a point where the ankle is neutral or slightly tied to a gait event. Such as foot flat, the equilibrium point of dorsiflexed (see FIG. 4, at , below). The “triceps Surae' at least one torsional means can be adjusted in the device, US 2012/0016493 A1 Jan. 19, 2012

leading to a change in the system's equilibrium point. This 0069 FIG. 2 shows how the linear braking mechanism adaptability allows for automatic adjustment to different (that is, linear lock/unlock) is represented in FIG. 3. FIG. 3 walking Surface inclinations. shows the action of the ankle-foot device throughout the gait 0065. As shown in FIGS. 6A through 6F, at initial contact cycle. of the heel with the walking surface, the brake is unlocked 0070 FIG. 4, as disclosed above, illustrates a torque curve allowing free movement. The neutralizing springs are com plot of the prior art using two neutralizing springs (NS). Note pressed (and/or stretched) as the ankle moves into a plantar that the single equilibrium point at . There is no transition flexed position (that is, as the forefoot comes down to make point since there is only one plane of movement. contact with the floor). During this time, the triceps surae 0071 FIG. 5, as disclosed above, illustrates a torque curve spring remains at its resting length while the braking mecha plot using a single “triceps Surae spring (TS). Note the single nism changes its length or angle (depending on linear or equilibrium point at B. rotational realization of the device). At the time when the 0072 FIG. 6 illustrates exemplary torque curve plots of ankle stops moving in the direction of plantarflexion and the invention showing that there are two equilibrium points. begins to move into dorsiflexion (that is, at the point of maxi In FIG. 6, the dotted line represents the predicted torque curve mum plantarflexion), the braking mechanism locks. This of an NS spring. The dashed line represents the predicted locking action sets the equilibrium point of the triceps Surae torque curve of a TS spring. The thin solid line represents spring at the point of maximum plantarflexion. As the person predicted torque curve of the combination of the NS and the rolls forward (during Perry's second rocker (1992) Gait TS. The thick solid line represents an actual torque curve plot Analysis: Normal and Pathological Function, Thorofare, showing the transition point (P). FIGS. 6A and 6B show the SLACK Inc.), the triceps Surae spring is stretched creating an invention in use on an incline, FIGS. 6G and 6D show the appropriate ankle moment for walking or the like. After oppo invention on a level surface. FIGS. 6E and 6F show the site heel contact, the load is removed from the device and the invention in use on a decline. FIGS. 6B, 6D, and 6F addition triceps Surae spring returns stored energy to the leg by plan ally show the path (heavy line) of a single gait cycle; note the tarflexing the ankle. When the load is almost fully removed, transition point (intersection) of the two torque curves. FIGS. the ankle will be close to the resting length of the triceps surae 6B, 6D, and 6F show that the invention can have multiple spring and the ankle will be at an angle of plantarflexion that transition points and that relative position of the transition is close to that at which the braking mechanism was locked. point on the curve plot is related to the gradient (incline, level. When the ankle plantarflexion angle comes within a threshold or decline) of the surface. Note also that the torque curve value of the amount that it acquired in early stance, the brak shifts to the left (negative ankle dorsiflexion angle) from ing mechanism is released. As the foot leaves the floor in early going uphill (incline), through level Surface, and going down Swing, the neutralizing springs bring the ankle into a neutral hill (decline). or slightly dorsiflexed position (back to position at) to allow 0073. The springs are chosen to replicate impedance val for better clearance between the toe and the floor in Swing ues found for able-bodied human walking (Hansen et al., phase. In the alternative, the braking mechanism can be (2004b) “The Human Ankle During Walking: Implications released when a load, such as the weight of the user, is for Design of Biomimetic Ankle Prostheses and Orthoses' J. released from being applied to the device. Biomech. 37: 1467–1474). These values change somewhat with walking speed but will be designed based on slow to Improvements of the Invention Over Existing Technologies normal walking speeds. The characteristics for extremely fast 0066. The improvements over existing technologies walking speeds cannot be mimicked using a passive system include the ability to adapt to various shoe heel heights and (Hansen et al., 2004b. Supra). A diagram of the ankle imped walking inclinations and the provision for plantarflexion at ance characteristics found for twenty four able-bodied ambu late stance. The device may prove to be Superior in energy lators (individuals) is shown in FIG. 7. Notice how this char storing and release characteristics over existing devices acteristic matches closely the characteristic drawn in the although this remains to be seen. Koniuk (2002) has stated the diagrams of FIGS. 3-6 showing that the prosthetic system and claim of adaptation to shoe heel height and walking inclina the ankle-foot device of the invention automatically adapt to tion in a recently patented design that utilizes damping-con different surface conditions. trol. Our design differs from Koniuk's (2002) in that it utilizes 0074 This concept can also be used in a rotational sense stiffness control and biomimetic foot roll-over shape, allow and in the field of orthoses. An equilibrium-point ankle-foot ing the device to achieve an ankle-foot roll-over shape similar orthosis (AFO) design that uses rotational components is to that of an able-bodied person's ankle-foot system during shown in FIG. 8. walking, while also allowing for energy return and plantar (0075 FIGS. 35 and 36 illustrate exemplary ankle systems flexion in late stance. of the invention showing a pylori (106); a hinge bar (107), a hinge spring (108), a cam engagement link (109), a drive cam Design and Manufacture of the Invention (110), a main cam (111), a Triceps Surae Spring (TS) (112), a footplate (113), a foot shell (114), an ankle frame (115), and 0067. This design is realized in a number of ways. Rota a Neutralizing Spring (NS) (116), an alternative actuator tional springs, linear springs, or combinations of the two are (117), and means for attachment to a leg (118). used to Supply the appropriate impedances about the ankle at 0076 FIG. 35 illustrates an alternative embodiment different stages of the walking cycle. In the following dia wherein an actuator moves the descending link. In another grams, however, the concept of the device will be illustrated alternative, to move the descending link weight activation using linear springs to describe an “equilibrium-point pros from beneath the footplate of an orthosis that would interact thetic ankle joint. with the drive cam through an ascending link may be used, 0068 FIG. 1 is an exemplary diagram of the device point wherein the linkage may be restructured to push the drive cam ing out the various components of the device. upward during loading. This may be achieved by connecting US 2012/0016493 A1 Jan. 19, 2012

the posterior pin of the drive cam to the ankle frame and the ratchet mechanism, a ball joint (such as disclosed in U.S. Pat. anterior pin of the drive cam to the ascending link coming up No. 6,217.249 to Merlo, issued Apr. 17, 2001), selectively from the footplate load activation system. engageable and disengagable mechanisms, and joint locking 0077 FIG. 37 shows exemplary incremental gait cycles mechanisms as disclosed in, for example, U.S. Pat. No. 6,159, where the TS can be from between 0° through 5° through 10°, 248 to Gramnas, issued Dec. 12, 2000, U.S. Pat. No. 6,436, and where the NS can be from 10° plantarflexion through 0° 149 to Rincoe, issued Aug. 20, 2002). The prosthetic system through 10° dorsiflexion. can also be combined with at least one microprocessor com 0078 FIGS. 38, 39, and 40 show exemplary incremental prising a software program or other instructional means that gait cycles where the TS can be from between 0° and 10°, and in combination can provide a control means. The control where the NS can be from 10° plantarflexion through 0° means can measure the torsion within the system and/or the through 10° dorsiflexion. angular movement of the ankle and thereby control the engagement means and the torsional means during each step Exemplary Embodiments of the Invention cycle or gait cycle. Such microproccessors and Software pro 0079. In one preferred embodiment, the range of movable grams are well known to those of skill in the art. contact of the first cam (for example, the drive cam) in contact 0085. There now follows a non-exhaustive list of different with the second cam (for example, the main cam) is not devices and/or mechanisms known to those of skill in the art greater than 95°. For example, the range of moveable contact that can be used with the invention. can be >0,5°, 10°, 15, 20, 259,300,350, 40°, 45,500,550, Engagement Means 60°, 65°, 70°, 75°, 80°, 85°, 90°, and 95° and any angle therebetween. Types of Clutch 0080. In another preferred embodiment, the ankle system I0086 Automatic clutch, backstopping clutch, ball clutch, has a plantarflexion-dorsiflexion range of from between 80° bidirectional clutch, brake-clutch combination, cam clutch, plantarflexion to about 15° dorsiflexion. For example, the cam and roller clutch, centrifugal clutch, cone clutch, detent range of plantarflexion can be >0,5°, 10°, 15, 20°, 25°,30°, slip clutch, disc clutch, dog clutch, double clutch, double 35°, 40°, 45°, 50°, 559, 60°, 65°, 70°, 75°, and 80° and any spring clutch, dual-spring slip clutch, duplex clutch, driving angle therebetween. In another example, the range of dorsi clutch, eddy current clutch, electrostatic clutch, expanding flexion can be >0°, 1, 2, 3, 4, 5, 6°, 7, 8°, 9°, 10°, 11, shoe clutch, externally controlled positive clutch, external 12°, 130, 14°, 15, 16°, 17, 180,199, 20, 259, 30°, 35,409, control clutch, internal control clutch, fixed-field clutch, fluid and 45° and any angle therebetween. Where there is neither clutch, free-wheeling clutch, friction clutch, multiple disc plantarflexion nor dorsiflexion the ankle system is at 0°, neu clutch, detente clutch, plate clutch, hysteresis clutch, index tral. ing clutch, internally controlled clutch, jaw clutch, lawn 0081. The expected commercial applications include mower clutch, bidirectional locking clutch, locking clutch, ankle-foot prostheses and orthoses for persons with disabili magnetic friction clutch, magnetic particle clutch, magnetic ties. These components would hopefully improve the mobil fluid clutch, magnetostrictive clutch, mechanical clutch, mer ity of these persons by allowing them to automatically adapt cury-gland clutch, multidisk clutch, multistation clutch, one to various walking Surfaces while at the same time giving way clutch, overload relief clutch, overriding clutch, overrun them biomimetic ankle-foot roll-over shape as well as storage ning clutch, planetary transmission clutch, plate clutch, roller and release of energy from the prosthesis at the appropriate clutch, roller clutch, rotating-field clutch, sliding-key clutch, times. The device can also allow for automatic adaptation for slip clutch, spiral-band clutch, Sprag clutch, spring clutch, different heel heights, allowing a user to use a variety of spring and ball radial detent clutch, station clutch, tooth different shoes. The devices can also be used in walking clutch, torque limiting clutch, trip clutch, wedging ball or machines, legged robots, and toys. roller clutch, and wrap spring clutch. 0082. The prosthetic or orthotic foot can be manufactured from a variety of compositions and a variety of combination Types of Brake of compositions. The prosthetic foot can comprise a compo sition selected from the group consisting of stainless steel, 0087 Air brakes, anti-lock brakes, coaster brakes, disc copper, aluminum, titanium, metal matrix composite, metal brakes, drum brakes, eddy current brakes, electric brakes, alloy, such as NITINOL, DELRIN (acetal), acrylonitrile friction brakes, hub brakes, hydraulic brakes, multi-disc butadiene styrene (ABS), nylon, polypropylene, polybro brakes, power brakes, rim brakes, spoon brakes, band brakes, mate, polycarbonate, glycolised polyethylene terephthalate and caliper brakes. (PETg) copolyester, polytetrafluorethylene (PTFE), ePTFE, polypropylene, or another polymer, glass fiber-resin compos Types of Lock ites, other composite materials, and the like, and, optionally, I0088 Cruciform lock, cylinder lock, deadbolt lock, disc that can be easily machined, compression molded, or injec tumbler lock, electronic lock, magnetic lock, electric strike tion molded to the required shape. lock, level tumbler lock, Chubb detector lock, protector lock, 0083. The prosthetic foot can be shaped and sized for padlock, pin tumbler lock, wafer tumbler lock, warded lock, purposes of mass manufacture in a standard size and shape. In 5 lever lock, keycard lock, rim lock, combination lock, and the alternative, it can be manufactured to specifications for a pin lock. single individual. The prosthetic foot can be manufactured using modular components, the modular components having Torsional Means different shapes, sizes, and compositions. 0084. The ankle of the prosthetic foot can comprise a Types of Spring locking mechanism, for example the locking mechanism can I0089. Coil or helical spring, tension spring, compression be selected from the group consisting of a pair of cams, a Spring, leaf spring, V-spring, spiral spring, clock spring, can US 2012/0016493 A1 Jan. 19, 2012 tilever spring, Belleville washer spring, spring washer, tor merely for purposes of illustration of certain aspects and sion spring, gas spring, rubber band, elastic elements, embodiments of the present invention and not as limitations. bumpers, umbrella springs, conical springs, taper springs, disc spring, and extension spring. EXAMPLES Types of Damper Example I 0090 Backdraft damper, barometric damper, butterfly Use of Weight-Activation to Control the Ankle damper, curtain damper, dual tube damper, flap damper, free Mechanism piston monotube damper, guillotine damper, louvre damper, 0141 Engagement can be set to occur upon loading of the sliding damper, and vibration damper. device by the user's weight. In this case, a mechanism is in place that engages the triceps Surae torsional means after a REFERENCE NUMERALS sufficient amount of body weight has been applied to the 0091 1. Foot member system. Upon unloading of the device, the engagement 0092. 2. Bearing reverses (that is the triceps Surae spring is disengaged from 0093. 3. Arm the rest of the system). Examples of this type of engagement 0094. 4. First cam are shown in FIGS. 9, 34, 35, 36, 37,38, 39, and 40. 0.095 5. Spacer 0096 6. Spring or second bumper (Torsion means) Example II 0097 7. Block 0098 8. Set screw Use of Potentiometers or Encoders to Control Lock 0099 9. Second cam (Engagement means) ing-Unlocking Mechanisms 0100 10. Spring or first bumper (Torsion means) 0142. The projected ankle motion of this device is shown 01.01 11. First shaft in FIG. 33. The potentiometers or encoders measure these 01.02 12. Second shaft angles during use of the device. In early stance, the locking (0103 13. Third shaft mechanism may be unlocked. When the rotational sensor 0104 14. Fourth shaft indicated that a minimum dorsiflexion angle is reached (at 0105 15. First aperture time 1), the system will signal to engage the locking mecha 0106 16. Second aperture nism. This mechanism remains engaged until this angle is 01.07 17. Recess approached at the end of stance phase (at time 2), at which 0108. 18. Link time the system unlocks and allows the neutralizing springs to 0109 19. Housing bring the ankle back to neutral for Swing phase. 0110 20. Threaded aperture 0111. 21. Bolt Example III 0112 22. First linkaperture 0113. 23. Compression spring Use of Forefoot Pressure Sensors to Control Lock 0114 24. Adaptor ing-Unlocking Mechanisms 0115. 25. Bolt aperture 0.143 An alternative way to control the locking and 0116 26. First aperture (arm) unlocking mechanism is to use a forefoot pressure sensor. In 0117 27. Second aperture (arm) early stance, the ankle plantarflexes until the forefoot contacts 0118, 28. Aperture (first cam) the walking surface. At this first contact with the forefoot 0119. 29. Surface (adaptor) pressure sensor, the locking mechanism may be engaged. 0120 30. Surface (housing) Forefoot contact remains until the toe comes off of the ground 0121 31. Bolt aperture (arm) at the end of stance. At this time, the pressure goes to Zero and 0122 32. Internal gear the locking mechanism could be unlocked, allowing the neu (0123. 33. External gear tralizing springs to bring the ankle back to neutral for Swing 0.124 101. Ankle-foot system phase. 0.125 102. “Triceps surae' (TS) spring means 0126 103. Linear Lock/Unlock means Example IV 0127 104. “Neutralizing spring(s) means 0128 105. Ankle Joint Use of Pylori Moments to Control Unlocking of a 0129. 106. Pylori Cam Mechanism 0130 107. Hinge Bar 0144 Devices to measure moments on the pylori maybe 0131) 108. Hinge Spring used to indicate the time at which a cam locking mechanism 0132) 109. Cam Engagement Link should be unlocked. The cam mechanism disclosed herein 0133 110. Drive Cam automatically sets the equilibrium point of the ankle in early 0134. 111. Main Cam stance but needs a control signal at late stance to release the 0135) 112. “Triceps Surae” Spring (TS) cam. After the middle cam is engaged and the front bumperis 0.136) 113. Footplate compressed, a moment is produced on the pylori that can be 0137) 114. Foot shell measured. After the load is removed from the leg, this 0138 115. Ankle Frame moment should go to Zero. Thus a circuit or microprocessor 0139) 116. “Neutralizing” Spring (NS) could note the falling edge of a pylori moment and use this 0140. The invention will be more readily understood by falling edge as a trigger to unlock the cam mechanism after reference to the following examples, which are included toe off. US 2012/0016493 A1 Jan. 19, 2012

(0145 FIG.1. Illustration of the “Equilibrium-Point Pros Applicants submit that many other shapes and positions may thetic Ankle Joint. also have optimal characteristics. For example, the sites of 0146 FIG. 2. The linear braking mechanism (that is, “lin contact between the two cams may be smaller, or they may be ear lock/unlock”) is shown in the following figures as clear greater than illustrated. The shape and size of the drive cam when it is unlocked and is shown in gray shading when it is may be engineered using methods well know to those of skill locked. in the art resulting in a even more optimal design. The shape 0147 FIGS. 3A, 3B, and 3C. The initial loading phase for and size of the main cam may be engineered using methods the device. The braking mechanism is unlocked allowing the well know to those of skill in the art resulting in an even more foot to be lowered to the floor against the resistance of the optimal design. The shape and size of the cams may be opti neutralizing springs. This action mimics what Perry (1992, mized for the manufacturing process and may differ from the supra) refers to as the first rocker or the heel rocker and drawings. corresponds to the first double-support part of the gait cycle. 0154 FIGS. 14 through 20 illustrate different exemplary 0148 FIGS. 3D, 3E, and 3F. Continuing from FIG. 3C, stages of the invention when being used to walk upon inclined when the ankle dorsiflexion angle stops decreasing and or declined Surfaces. begins to increase the braking mechanism locks (left). The (O155 FIGS. 21 through 31 illustrate different exemplary person then rolls over on the ankle joint as the triceps Surae stages of walking having controlled plantarflexion using neu spring is stretched (middle and right). Perry (1992, supra) tralizing springs as embodied in the invention. refers to this as the second rocker or ankle rocker. This period 0156 FIG. 32 illustrates experimental data from one sub of time corresponds most closely with the single-limb stance ject having unilateral transtibial amputation. FIG. 32 shows period of gait. that the torque curve of the invention used in a single gait on 0149 FIGS. 3G and 3H. Continuing from FIG. 3F, after a variety of inclined, level, and declined surfaces shifts to the the opposite heel contacts (which would be FIG. 3J) the load left (negative) as predicted above in FIG. 6. is rapidly removed from the system and some of the stored (O157 FIGS. 34 through 40 illustrate preferred embodi energy can be released back to the leg. The series of FIGS. 3G ments of the invention. and 3H show this unloading period. At the end of the unload 0158 Those skilled in the art will appreciate that various ing period, when the dorsiflexion gets near the point where adaptations and modifications of the just-described embodi the braking mechanism locked, the brake is released. Perry ments can be configured without departing from the scope (1992, supra) refers to this period as the third rocker or the and spirit of the invention. Other suitable techniques and forefoot rocker. This period of time corresponds most closely methods known in the art can be applied in numerous specific with the second part of double-limb support of walking. modalities by one skilled in the art and in light of the descrip 0150 FIGS. 3I, 3J, and 3K. Continuing from FIG.3H, as tion of the present invention described herein. Therefore, it is the braking mechanism is unlocked the foot is coming off the to be understood that the invention can be practiced other than ground and preparing to Swing. In order to avoid stubbing the as specifically described herein. The above description is toes, the ankle needs to go back into a neutral or slightly intended to be illustrative, and not restrictive. Many other dorsiflexed position. Since the braking mechanism is embodiments will be apparent to those of skill in the art upon unlocked, the neutralizing springs again dominate and pull reviewing the above description. The scope of the invention the foot upwards to a proper position for Swing phase. should, therefore, be determined with reference to the 0151 FIG. 7. Average ankle moment versus dorsiflexion appended claims, along with the full scope of equivalents to angle plot for 24 able-bodied ambulatory (adapted from which such claims are entitled. Hansen et al., 2004b). Springs will be selected such that the We claim: overall impedance of the ankle-foot device mimics this char 1. A self-adapting prosthetic system, the self-adapting acteristic. The asterisk shows the time at which opposite heel prosthetic system comprising a foot shell, an improved pas contact occurs. Theoretical ankle moment versus ankle dor sive adaptive ankle-foot prosthesis, and means for attachment siflexion characteristics for the anklejoint are shown in FIGS. to a leg, the ankle foot prosthesis comprising a footplate, an 3-6. ankle system, the ankle system comprising a housing, a first 0152 FIG. 8. Equilibrium-point ankle-foot orthosis cam, a second cam, a bracket, wherein the housing and the (AFO). This design is similar to the equilibrium-point pros bracket are fixedly attached to the means for attachment to the thetic ankle-foot mechanism except it uses rotational compo leg, wherein the bracket is fixedly attached to the first cam, nents instead of translational. The neutralizing springs are not wherein the first cam is in movable contact with a part of the shown but are provided by technology that is already avail second cam and the first cam and second cam comprise a cam able (Klenzak ankle units). These joints can be altered to clutch system, and wherein the footplate comprises an ante allow different amounts of dorsiflexion or plantarflexion. riorportion and a posteriorportion and further comprising an They contain spring elements that could act as the neutraliz essentially horizontal plantar member, a torsion means, and ing springs. Other neutralizing joints could also be used. The an essentially vertical member, the vertical member being main elements shown here are the rotational “triceps-surae' perpendicular to the horizontal plantar member and opera spring in series with a rotational lock-unlock mechanism. tively attached to the posterior portion of the footplate, the 0153 FIG. 9. The improved equilibrium-point prosthetic Vertical member further comprising an aperture, the aperture or orthotic ankle joint device that incorporates a nested drive shaped and adapted to confine at least one neutralizing ele cam within the main cam, as well as the simple hinge is ment and a spacer, the neutralizing element being operatively illustrated. FIG. 34 illustrates the equilibrium-point pros connected to the spacer, wherein the spacer is axially con thetic or orthotic ankle joint device in use showing the posi nected to the housing, wherein the housing is axially con tions of the simple spring and the drive cam and main cam nected to the vertical member of the footplate, and wherein through a complete exemplary step cycle. Although the cams the second cam is axially connected to the vertical member of illustrated have been found to be shaped for optimal function, the footplate and wherein the torsion means is shaped and US 2012/0016493 A1 Jan. 19, 2012 adapted for confined placement between the second cam and connected to the spacer, wherein the spacer is axially con the horizontal plantar member, and wherein the improved nected to the housing, wherein the housing is axially con passive adaptive ankle-foot prosthesis is shaped and adapted nected to the vertical member of the footplate, and wherein for placement within the foot shell and wherein the foot shell the second cam is axially connected to the vertical member of comprises, in part, a flexible material. the footplate and wherein the torsion means is shaped and 2. The self-adapting prosthetic system of claim 1 further adapted for confined placement between the second cam and comprising a second neutralizing element. the horizontal plantar member, and wherein the improved 3. The self-adapting prosthetic system of claim 2, wherein passive adaptive ankle system is shaped and adapted for the neutralizing elements are selected from the group consist placement on at least one side of the biological ankle of the ing of a spring, a tunable spring, a clockwork spring, a piston, user or individual. a damper, a bumper, and an elastomeric material. 14. The self-adapting orthotic system of claim 13 further 4. The self-adapting prosthetic system of claim 1 wherein comprising a second neutralizing element. the torsion means is selected from the group consisting of a 15. The self-adapting orthotic system of claim 14, wherein Spring, a tunable spring, a clockwork spring, a piston, a the neutralizing elements are selected from the group consist damper, and an elastomeric material. ing of a spring, a tunable spring, a clockwork spring, a piston, 5. The self-adapting prosthetic system of claim 1 wherein a damper, a bumper, and an elastomeric material. the neutralizing element and the cam clutch are in-line. 16. The self-adapting orthotic system of claim 13 wherein 6. The self-adapting prosthetic system of claim 1 wherein the torsion means is selected from the group consisting of a the self-adapting prosthetic system comprises a composition Spring, a tunable spring, a clockwork spring, a piston, a selected from the group consisting of stainless steel, copper, damper, and an elastomeric material. aluminum, titanium, metal matrix composite, metal alloy, 17. The self-adapting orthotic system of claim 13 wherein NITINOL, DELRIN (acetal), acrylonitrile butadiene styrene the neutralizing element and the cam clutch are in-line. (ABS), nylon, polypropylene, polybromate, polycarbonate, 18. The self-adapting orthotic system of claim 13 wherein glycolised polyethylene terephthalate (PETg) copolyester, the self-adapting prosthetic system comprises a composition polytetrafluorethylene (PTFE), ePTFE, polypropylene, a selected from the group consisting of stainless steel, copper, polymer, glass fiber-resin composites, and carbon fiber resin aluminum, titanium, metal matrix composite, metal alloy, composites. NITINOL, DELRIN (acetal), acrylonitrile butadiene styrene 7. The self-adapting prosthetic system of claim 1, wherein (ABS), nylon, polypropylene, polybromate, polycarbonate, the second cam comprises an external Surface and an internal glycolised polyethylene terephthalate (PETg) copolyester, Surface. polytetrafluorethylene (PTFE), ePTFE, polypropylene, a 8. The self-adapting prosthetic system of claim 7, wherein polymer, glass fiber-resin composites, and carbon fiber resin the first cam is in movable contact with the internal surface of composites. the second cam. 19. The self-adapting orthotic system of claim 13, wherein 9. The self-adapting prosthetic system of claim 8 wherein the second cam comprises an external Surface and an internal the range of movable contact of the first cam in contact with Surface. the second cam is not greater than 95°. 20. The self-adapting orthotic system of claim 19, wherein 10. The self-adapting prosthetic system of claim 1, wherein the first cam is in movable contact with the internal surface of the ankle system has a plantarflexion-dorsiflexion range of the second cam. from between 80° plantarflexion to about 45° dorsiflexion. 21. The self-adapting orthotic system of claim 20 wherein 11. The self-adapting prosthetic system of claim 1, further the range of movable contact of the first cam in contact with comprising a foot shell. the second cam is not greater than 95°. 12. The self-adapting prosthetic system of claim 1, wherein 22. The self-adapting orthotic system of claim 13, wherein the means for attachment to a leg are selected from the group the ankle system has a plantarflexion-dorsiflexion range of consisting of a residual limb Socket, direct skeletal attach from between 80° plantarflexion to about 45° dorsiflexion. ment to the residual limb, and a leg cuff. 23. The self-adapting orthotic system of claim 14, wherein 13. A self-adapting orthotic system, the self-adapting the improved passive adaptive ankle-foot prosthesis is shaped orthotic system comprising a footplate, an improved passive and adapted for placement on at least one side of the ankle of adaptive ankle system, and means for attachment to an ankle, a user or individual. the ankle system comprising the footplate, means for attach 24. The self-adapting orthotic system of claim 13, wherein ing to the means for attachment to an ankle, a housing, a first the means for attachment to an ankle are selected from the cam, a second cam, a bracket, wherein the housing and the group consisting of a residual limb socket, direct skeletal bracket are fixedly attached to the means for attachment to the attachment to the residual limb, a clamshell socket, and a leg ankle, wherein the bracket is fixedly attached to the first cam, cuff. wherein the first cam is in movable contact with a part of the 25. The self-adapting orthotic system of claim 13, wherein second cam and the first cam and second cam comprise a cam the means for attaching to the means for attachment to an clutch system, and wherein the footplate comprises an ante ankle comprises a hinge bar and a hinge spring. riorportion and a posteriorportion and further comprising an 25. The self-adapting orthotic system of claim 13, wherein essentially horizontal plantar member, a torsion means, and the orthotic system further comprises an actuator. an essentially vertical member, the vertical member being 26. The self-adapting orthotic system of claim 25, wherein perpendicular to the horizontal plantar member and opera the actuator Substitutes for the hinge bar and the hinge spring. tively attached to the posterior portion of the footplate, the 27. A method for providing essentially normal gait in an Vertical member further comprising an aperture, the aperture amputee, the amputee having lost a lower limb extremity, the shaped and adapted to confine at least one neutralizing ele method comprising (i) providing the self-adapting ankle-foot ment and a spacer, the neutralizing element being operatively device of claim 1; (ii) attaching the self-adapting ankle-foot US 2012/0016493 A1 Jan. 19, 2012

device to the lower limb of the amputee; (iii) allowing the 29. The method of claim 28 wherein the engagement and amputee to ambulate for at least one gait cycle, the gait cycle dampening of the engagement means coincides with a first comprising at least two phases of dorsiflexion over time, transition point of the torsion curve plot. whereby a load applied during a first phase of dorsiflexion 30. The method of claim 28 wherein the disengagement and release of the engagement means coincides with a second results in the engagement means engaging and damping transition point of the torsion curve plot. movement of the engagement means, wherein during the first 31. The method of claim 28 further comprising a step of phase when the Velocity of ankle dorsiflexion angle change determining an equilibrium point, wherein the equilibrium equals Zero the engagement means engages and dampens point of the torsion curve plot is at a negative dorsiflexion fully, and wherein during a second phase of dorsiflexion when angle. the Velocity of ankle dorsiflexion angle change equals Zero 32. The method of claim 28 further comprising a step of the engagement means disengages and releases fully, the determining an equilibrium point, wherein the equilibrium method resulting in providing essentially normal gait to the point of the torsion curve plot is at a positive dorsiflexion amputee. angle. 28. The method of claim 27 wherein the gait cycle com prises at least three phases of ankle flexion.