JPS6026536B2 - prosthetic ankle device - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ankle joint device for a prosthetic leg, and in particular, a hydraulic pump mechanism provided between the lower leg and the foot allows the foot to move during the swing phase of prosthetic leg walking. This invention relates to an ankle joint device that eliminates walking by keeping the ankle in a dorsiflexed position.

[Conventional technology]

When a person with normal thighs walks, when the biological foot shifts from the stance phase where it supports the body weight and rests on the floor to the swing phase by kicking off in the direction of movement, the foot dorsiflexes, so the front of the foot The device does not hit the floor and lie sideways, but instead moves straight and lands in a desired position in front of it, allowing it to walk normally.

An ankle joint device for a prosthetic leg that has the same effect as the above-mentioned normal walking of a healthy lower limb has not been proposed.

In other words, the foot of a conventional prosthetic leg is fixed at right angles in front of the lower leg, and when the foot of the prosthetic leg, which is planted on the back side of the normal leg, is swung forward in the direction of movement and enters the thoracic phase, the foot The total length of the prosthetic lower limb up to the tip of the prosthesis appears to be longer than that of a healthy lower limb, and the tip of the foot may carelessly touch the floor.
There is a risk of colliding with a bump or obstacle on the floor and falling. Therefore, a person wearing a prosthetic leg has no choice but to adopt an abnormal gait in which the prosthetic leg is swung out to the side, and the prosthetic leg is turned in a diagonal manner to place the saddle at a desired position in front of the user. Furthermore, in recent years, an ankle joint axis has been provided between the lower leg and the foot, and a foot that can plantar-dorsiflex has been provided by interposing an elastic elastic member such as rubber on the front and rear sides of the ankle joint axis, and the load has been increased. A structure that is held in front at right angles to the lower leg when not in use has been proposed.

However, even in the ankle joint device having such a configuration, when the prosthetic leg moves to the swing position, the prosthetic leg returns to the front at right angles to the lower leg, and there is no dorsiflexion. [Agenda to be solved by the invention] Therefore, when walking with a prosthetic leg, the dorsiflexed foot lands on the ground from the base and plantarflexes, causing the entire sole of the foot to become warm, just like the normal gait of a healthy person (pedestrian). After resting on the floor, as the lower leg moves forward, the foot begins to dorsiflex under a greater load than during plantarflexion.
There is a need for a prosthetic walking device in which the foot operates so that when the prosthetic leg is swung forward and transitions to the swing phase, the foot is dorsiflexed and transitions to the next stance phase.

[Means for resolving issues]

In light of the current situation, the ankle joint device for the prosthetic leg of the present invention has a hydraulic pump mechanism with a foot ball fixed at a position corresponding to the biological ankle joint of the foot, and the lower end of the lower leg is attached to the foot shaft, In the hydraulic operation chamber of the hydraulic pump mechanism, pintons fixed to the foot ball reciprocate back and forth in an arc, and the sliding range is within the range in which the foot of a healthy human being undergoes plantar dorsiflexion.

Furthermore, an oil flow path is provided between the front chamber and the rear chamber, where the hydraulic working chamber is divided by the piston. The oil fluid flows through the channel between the two, thereby causing the foot to plantar dorsiflex. Furthermore, a pair of passages are provided, one passage is provided with a check valve that allows the oil to flow from the front chamber to the rear chamber, and a regulating valve that controls the flow rate, and the other passage is provided with a check valve that allows the oil to flow from the front chamber to the front chamber, and the other passage is provided with a check valve that allows the oil to flow from the front chamber to the rear chamber. A check valve through which the foot flows and an adjustment valve to control the flow rate are provided to provide bending resistance to accommodate the difference in body load applied when the foot is plantarflexed and dorsiflexed so that normal walking can be achieved. This is what is done.

Furthermore, since the bending resistance of the foot differs depending on the weight of each person and the pedestrian, the check valve and the adjustment valve are used to provide an ankle joint device in which the hydraulic pump mechanism can be adjusted from the outside. [
Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

〔composition〕

The foot part 1 shown in FIG. 1 is molded from a flexible rubber or synthetic resin material having elasticity, and has a keel 2 as a rigid body in the longitudinal direction of the central part and a prosthetic foot disposed from the tip of the keel 2 to the toe part. Generates a ground reaction force when swinging out.

The elastic body 3 is integrally cast. A hydraulic pump mechanism 5 constituting an ankle joint device is fixed to the rear upper surface of the keel 2 via a pedestal 6 integral therewith.

An inverted U-shaped mounting frame 8 is fixed to both ends of the rotatable leg shaft 7, which is the central shaft of the pump mechanism 5, and a threaded joint 9 is inserted from the center upper surface of the upper frame portion of the mounting frame 8. A lower leg portion 10 made of a pipe is erected. The main body 11 constituting the pump mechanism 5 is formed by attaching lid frames 19 and 19' to both ends of a central ring frame 12 and a far frame 12 with screws 20, which stand up on a pedestal.

Mounting members 13 protruding from the front and rear of the upper peripheral surface of the ring frame 12,
A holding punch 16 curved concentrically with the ring frame 12 is mounted between the rings 14 and 14, and the holding punch 16 is loosely inserted into a ring 17 that protrudes downward from the center of the lower surface of the upper frame of the mounting frame 8. ing. A transverse pressure coil 15 is inserted in the holding village 16 between the ring 17 and the attachment village 14, and the foot is biased in the dorsiflexion direction with a controlled weak force. This biasing force in the dorsiflexion direction is a force that maintains the dorsiflexion state when the foot transitions from the stance phase to the swing phase. At the center of both the lid frames 19, 19', the foot pad 7 is mounted with a circular ring 24 in an oil-tight and rotatable manner.

The inner small diameter portions 25 of both lid frames 19, 19' are adjacent to each other within the inner circumferential surface of the ring frame 12, and a hydraulic operating chamber 29 is formed by the interval between the inner surfaces of both small diameter portions 25 and the inner circumferential surface of the ring frame. do. Further, the lower portions of the two diameter portions 25 form inward protrusions 27, and the inner end surfaces of these protrusions are brought into close contact with each other. The front end surface 32 and rear end surface 33 of the working chamber 29 formed by both projections 27 are formed in a plane radially extending from the center line of the foot shaft 7, so that the working chamber has a fan-shaped cross section. There is. On the other hand, a piston 22 having a fan-shaped cross section and having a center angle smaller than the center angle of the fan-shaped working chamber is fixed to the inner part of the working chamber 29 of the foot shaft 7, and the working chamber 29 is connected to the front chamber 30 by this piston 22.
and a rear chamber 31 are formed separately. And piston 22
When the front end surface 45 of the piston 22 comes into contact with the front end surface of the working chamber, the foot 1 is dorsiflexed by about 150 degrees, which is the maximum dorsiflexion angle of a living foot, and the rear end surface 46 of the piston 22 contacts the rear end surface 33 of the working chamber. The center angle of the fan-shaped piston 22 is set so that the foot 1 is plantar flexed by about 30°, which is the plantar flexion limit of a living foot. The front chamber 30 and the rear chamber 31 are filled with oil, and the oil is moved both forward and backward by the front and back of the lower leg 10, which is loaded with body weight, and the plantar dorsiflexion of the foot. A pair of drains 36, 36' that extend into the chamber are bored in both lid frames.

The flow path 36 is bored inside the lid frame 19.

That is, the protrusions 27 forming the front and rear chambers 30 and 31 are bored downward from the front and rear end surfaces 32 and 33, then bent horizontally, and then bent further upwards, and a horizontal flow path section is formed between the upper ends. Good luck. The rear chamber 31
The flow rate flowing only in the direction of the front chamber 30 from the front chamber 30 can be adjusted from the outside. The pressing force of the check valve 35 is adjusted from the outside with a presser screw 39 via a spring 38. Further, the flow rate regulating valve 40 is adjusted by rotating a threaded valve stem with a head 41. The channel 36' is bored in the lid frame 19', and the shape of the channel 36' is symmetrical to the channel 36.

By installing a check valve 35' at the front end of the horizontal flow path section and installing a flow rate adjustment valve 40' at the rear end, the flow rate of the oil is regulated from the front chamber 30 to the rear chamber 31 direction. do.
The structure of the check valve 35' and the regulating valve 40' is the same as that of the valve 35 and the regulating valve 40' described above.
It has the same structure as 40. [Operation] The operation of this embodiment configured as described above will be explained based on FIG. 5.

FIG. 5c shows the mid-stance stage of walking with a prosthetic leg with the entire sole of the foot resting on the saddle floor and the lower leg 10 standing upright.

At this time, the upper end surface 45 has an elevation angle of 15o with respect to the lower horizontal end surface 32 of the front chamber 30, and the lower leg portion 10 is 1y
Lean forward to 1y or dorsiflex foot 1 to 1y. In comparison, the lower end surface 33 of the rear chamber 31 is 1y with respect to the horizontal plane.
The upper end surface 46 has an elevation angle of 15o with respect to the horizontal plane.Therefore, the lower leg 1 is tilted backward within a range of 30o, or the foot 1 is tilted backward within a range of 30o. is plantarflexed over a range of 30°. Figures a to e in Figure 5 show the transition phase of the stance part during prosthetic walking, and Figure a shows the transition phase of the stance part during the swing phase, after which the foot part 1 swings out in the dorsiflexion phase. The figure shows the relative positional relationship between the foot part 1 and the lower leg part 10.

At this time, the entire amount of the oil in the front chamber 30 has moved to the rear chamber 31 via the flow path 36'. Then, as the trunk moves forward, the entire sole of the foot reaches the shuntoko stage, as shown in Figure b.
At this time, the lower leg part 10 maintains the posterior flexion phase, but the foot part enters the plantar flexion phase, and a corresponding amount of oil moves to the anterior chamber 30 via the flow path 36. When the trunk moves further forward from the phase of the crus 10 in Figure b, the crus 10 stands erect and transitions to the mid-stance phase shown in Figure C. At this time, the entire body weight is applied to the prosthetic leg, and the other healthy limb has reached the mid-swing stage. The trunk in the middle of stance moves further forward due to inertia, and when the lower leg 10 moves forward 15 degrees, the upper and lower end surfaces 32 and 45 of the front chamber 30 come into contact and are locked. If an attempt is made to move the crus 10 forward any further, the body weight will be applied to the toes of the foot. As the trunk, which is located in front of the feet, moves forward, the seeds gradually leave the bed and the healthy limb transitions from the postseed bed stage to the plantar bed stage. At this time, the prosthetic leg moves from Figure d and exhibits the transition phase of the take-off stage shown in Figure e. The lower leg 10 then leans forward and the seed is completely lifted off the bed by the swinging motion. At this time, the toe with the elastic plate 3 inside is elastically dorsiflexed, and when the body load is released in this toe backwind phase, the ground reaction force becomes a kicking force and the prosthesis moves forward elastically. It is pushed out and shifts to the swing phase. In this respect, it is different from the case of a healthy limb, where the lower limb is swung forward by adding plantar flexion force of the foot and extension force of the thigh. Furthermore, the foot 1 exhibits a dorsiflexion phase similar to that in the treading phase shown in Figure d, and is urged in the dorsiflexion direction during the swing phase by the ground reaction force during the take-off phase. Furthermore, the foot maintains the dorsiflexion phase throughout the swing phase due to the viscosity of the oil in the rear chamber 31 and the frictional properties of the oil in the flow path. 0 [Effect] In the ankle joint device of the present invention having the above-described effects, the foot is dorsiflexed during the take-off phase in walking with a prosthetic leg, and this dorsiflexion state can be controlled by an oil liquid movement adjustment valve or an oil liquid provided in the hydraulic pump mechanism. Due to the nature of this, the dorsiflexed state is maintained even during the swing phase.

In addition, a coil is provided between the lower leg and the back of the foot, so even if the tip of the foot collides with a protrusion or other obstacle on the floor, it will not easily plantar flex. Therefore, abnormal gait such as the conventional split gait can be eliminated at once by the ankle joint device of the present invention. Furthermore, the body weight applied during plantar flexion and dorsiflexion of the foot are different, and the weight load during plantar dorsiflexion also differs depending on the gait (abnormal gait) of each individual prosthesis wearer. In response to this, separate flow paths for the oil liquid are provided for when the foot is in contact with the floor and when the foot is dorsiflexed, and a valve that adjusts the flow rate through which the oil flows apart is provided, thereby alleviating the impact caused by the foot touching the floor. Of course, the phase of the foot transitioning to the stance phase can now be made closer to the normal transition phase of the biological foot of a healthy person.

[Brief explanation of drawings]

Fig. 1 is an overall perspective view of the ankle joint device in which a hydraulic pump mechanism is interposed between the foot and the lower leg, Fig. 2 is a longitudinal sectional view along the foot direction of Fig. 1, and Fig. 3 is FIG. 4 is an exploded perspective view showing a foot shaft with a piston and a pair of lid frames with a narrow path that constitute the pump mechanism, taken from a in FIG. 5. e is an explanatory diagram showing changes in the transition phase between the lower leg and the foot during the stance phase of walking with a prosthetic leg equipped with the device of the present invention. 1... Foot section, 5... Hydraulic pump mechanism, 7...
...Ashimari, 10...Lower leg, 11...
・Land body, 12... Bonito body ring frame, 15... Coil spring, 19, 19'... Lid frame, 22... Piston, 27... Projection part, 29... Working chamber, 30... Front chamber, 31... Rear chamber, 36
, 36'...flow path. Figure 2 Figure 3 Mountain boat

Claims (1)

[Scope of Claims] 1. A housing 11 of a hydraulic pump mechanism 5 is fixed to the foot 1, and a foot shaft 7 is located at a position corresponding to the biological ankle joint, which is the axis of the housing 11.
is rotatably mounted, and both lower ends of an inverted U-shaped mounting frame 8 having a lower leg part 10 erected are fixed to both ends of the foot shaft 7 protruding outside the housing, and the lower ends of the inverted U-shaped mounting frame 8 are fixed to A working chamber 29 having a fan-shaped cross section is formed with the foot shaft 7 as the center, and the foot shaft portion in the working chamber 29 has a cross section having a central angle smaller by a predetermined angle than the central angle of the fan-shaped working chamber. A fan-shaped piston 22 is fixedly movable in a reciprocating manner, and between a front chamber 30 and a rear chamber 31 formed into an operating chamber by the piston 22 and filled with oil, there is a lower side of the two chambers. An ankle joint device for a prosthetic leg, characterized in that an oil fluid flow path 36 communicating with an end face is provided. 2 Front end surface 45 of the piston 22 constituting the front chamber 30
When the foot 1 comes into contact with the lower end surface 32 of the front chamber, the lower leg 1
The position of the front end surface 45 is set so that the front end surface 45 is dorsiflexed by 15 degrees with respect to The rear end surface 4 is bent so as to be plantar flexed by 30° with respect to 10.
6. The ankle joint device for a prosthetic leg according to claim 1, wherein the ankle joint device is set as follows. 3 The flow path is located at both lower end surfaces 32 of the front and rear chambers 30 and 31.
, 33 are provided, and the flow paths 36, 36' are equipped with check valves 40, 40', respectively, to allow the flow to flow in opposite directions, and to control the amount of oil passing through. An ankle joint device for a prosthetic leg according to claim 1, characterized in that regulating valves 35 and 35' are respectively installed to control the ankle joint device.