CN117815040A - Orthopedic spine postoperative back rehabilitation exercise device - Google Patents

Abstract

The patent application belongs to the technical field of rehabilitation training, and in particular relates to an orthopedic spine postoperative back rehabilitation exerciser, which comprises a traction mechanism and an auxiliary supporting mechanism, wherein the auxiliary supporting mechanism comprises two rotatable shank supporting plates, and a rotating fulcrum of each shank supporting plate is positioned below a knee; the traction mechanism comprises a first traction rope, a transmission assembly and two second traction ropes, one end of the first traction rope is fixedly connected with a wearing part, one end of the second traction rope is fixedly provided with a connecting part, and the connecting part is arranged on the lower leg supporting plate; the purpose is that: through the cooperation of first haulage rope, second haulage rope and drive assembly, the user only need concentrate on upper limbs or shoulder and exert a force, lifts up the shank through shank backup pad assistance, to the poor person of physical function, keeps the gesture that little swallow flies more easily, has guaranteed the recovered exercise effect of back.

Description

Orthopedic spine postoperative back rehabilitation exercise device

Technical Field

The invention relates to the technical field of rehabilitation training, in particular to a back rehabilitation exerciser after orthopedics backbone operation.

Background

The patient can exercise through the methods of flat support, small swallow, hip bridge, pull-up, swimming, and the like after the spine operation.

When the small swallow flies, the head needs to be slightly lifted upwards, the shoulders are lifted backwards, the upper limbs are lifted upwards, simultaneously, the two feet are lifted slightly, the muscle of the lumbosacral part is contracted, the rib and the abdomen support the body as much as possible, and the waist, the neck and the shoulder parts are kept for 3-5 seconds, so that the effect of relieving the strain of the waist, the neck, the shoulder parts and the like is achieved.

And for the patient after the backbone operation, the physical function is relatively poor, when carrying out little swallow and fly to temper, after lifting simultaneously with both feet, keep stable comparatively difficult, the health can take place to rock, can not reach better recovered effect of taking exercise.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the orthopedic spine postoperative back rehabilitation exerciser, the first traction rope, the second traction rope and the transmission assembly are matched, a user only needs to concentrate on the upper limbs or shoulders to exert force, the lower leg is lifted by the auxiliary of the lower leg supporting plate, and the posture of the small swallow is easier to keep for people with poor body functions, so that the postoperative rehabilitation is facilitated.

The technical scheme adopted by the invention is as follows:

the back rehabilitation exercise device comprises a traction mechanism and an auxiliary supporting mechanism, wherein the auxiliary supporting mechanism comprises two rotatable shank supporting plates, and a rotating fulcrum of each shank supporting plate is positioned below a knee;

the traction mechanism comprises a first traction rope, a transmission assembly and two second traction ropes, one end of the first traction rope is fixedly connected with a wearing part, one end of the second traction rope is fixedly provided with a connecting part, and the connecting part is arranged on a shank supporting plate;

after the wearing part is worn, when the shoulders and the upper limbs are lifted, the first traction rope is driven to pull the transmission assembly, the transmission assembly is controlled to pull the second traction rope, and the second traction rope pulls the shank support plate to lift upwards around the rotating pivot.

Working principle: the user fixes the wearing part on the upper limb or the shoulder, the shoulder and the upper limb exert force, lift upwards, thereby pulling the first traction rope, thereby triggering the transmission component, the transmission component pulls the second traction rope to turn upwards, lifts the shank part upwards, after keeping for 3-5 seconds, the user puts down the shoulder and the lower limb, the transmission component pulls back the first traction rope, loosens the second traction rope, and the shank supporting plate is restored to the initial position due to gravity.

Compared with the prior art, the invention has the beneficial effects that:

through the cooperation of first haulage rope, second haulage rope and drive assembly, the user only need concentrate on upper limbs or shoulder and exert a force, lifts up the shank through shank backup pad assistance, to the poor person of physical function, keeps the gesture that little swallow flies more easily, has guaranteed back recovered effect.

As a preferred embodiment of the present invention, the transmission assembly includes a first rotation shaft and a second rotation shaft which are arranged in parallel, the first rotation shaft is located at one side of the lower leg support plate close to the first traction rope, the second rotation shaft is located between the first rotation shaft and the lower leg support plate, the first rotation shaft is fixedly connected with a pulley, and the second rotation shaft is fixedly provided with three winding drums along the axis direction;

the other end of the first traction rope passes through the bottom of the pulley and is fixedly connected to a take-up reel at the middle part, the other end of the second traction rope passes through the upper end surface of the lower leg supporting plate and is fixedly connected to a corresponding take-up reel, and when the lower leg supporting plate is not lifted, the included angle between the lower leg supporting plate and the horizontal plane is larger than 0 degree;

the winding directions of the winding drums in the middle part are opposite to those of the winding drums at the two sides.

Working principle:

when the shoulder or the upper limb is lifted upwards, the first traction rope is pulled, the take-up reel at the middle part is used for paying off, the second rotating shaft is rotated, and the take-up reels at the two ends are driven to take up wires due to the opposite winding directions, so that the second traction rope pulls the lower leg supporting plate, the lower leg supporting plate is lifted upwards, when the shoulder or the lower limb is put down, the lower leg supporting plate falls down due to gravity, the second traction rope is pulled, the take-up reels at the two ends are used for paying off, and the take-up reels at the middle part are used for taking up wires, so that the first traction rope and the second traction rope are reset.

The beneficial effects are that:

when the wearing part is positioned on the upper limb, the upper limb drives the lower leg supporting plate to be lifted, so that the force applied by the lower limb can be reduced, and the balance is easier to keep;

when the wearing part is positioned on the shoulder, the shank supporting plate is driven to be lifted by the shoulder, so that the force required by lifting the back is increased, the exercise effect is enhanced, and the device is suitable for people with better physical functions.

As a preferred embodiment of the present invention, the transmission assembly further comprises a servo motor and a pressure sensor, wherein the pressure sensor is installed on the first rotating shaft, and an output shaft of the servo motor is fixedly connected with the second rotating shaft;

when the first traction rope is lifted upwards, the servo motor drives the second rotating shaft to rotate when the detection value of the pressure sensor is higher than a preset value, the take-up reel in the middle part pays off, and the take-up reels at the two ends take-up wires; when the detection value of the pressure sensor is lower than a preset range, the servo motor reversely rotates to reset the take-up reel.

Working principle: when the first traction rope is stretched, because the first traction rope passes through the sliding bottom, upward force is generated on the first rotating shaft, after the pressure sensor detects that the value exceeds a preset value, the servo motor is started to drive the second rotating shaft to rotate, and the rotating disc is wound or unwound according to the force condition of a user.

The beneficial effects are that:

1. the force applied to the legs is reduced by driving the servo motor, and no extra load is added to the upper limbs and the shoulders, so that the electric foot-rest is suitable for people with poor body functions;

2. through setting up servo motor, after servo motor outage, servo motor's output shaft can free rotation, and at this moment, upper limbs or shoulder can directly drive shank backup pad rotation.

As a preferred embodiment of the present invention, the lower leg supporting plate includes a third rotating shaft and a plate body, the plate body is fixedly connected to the third rotating shaft, a sliding groove is formed in an upper end surface of the plate body, and the connecting portion is slidably mounted in the sliding groove;

the plate body is provided with a plurality of limiting holes along the direction of the sliding groove, the limiting holes are communicated with the sliding groove, the connecting part is provided with a spring telescopic rod, the spring telescopic rod penetrates through the corresponding limiting holes, and a round angle is arranged at one end of the spring telescopic rod extending out of the limiting holes;

the spring telescopic rod is pressed into the sliding groove, and the connecting part can slide along the sliding groove.

The beneficial effects are that: through pressing the spring telescopic link, remove the connecting portion position, can change the distance between connecting portion and the take-up reel, the distance is longer, and the arm of force is longer, and the user is laborsaving more, and when wearing the portion and being located the shoulder, the lifting shoulder needs back muscle to exert a force, overcomes the weight of upper body and lifts up shank backup pad and shank, according to different crowd's exercise demand, the distance of adjustable arm of force to play more suitable exercise effect.

As a preferred embodiment of the invention, the take-up reel is fixedly connected with a connecting ring, the connecting ring is provided with a plurality of first through holes along the circumferential direction, the second rotating shaft is vertically provided with a second through hole, and a limiting pin is arranged in one through hole and the second through hole.

The beneficial effects are that: when the effective length of the first traction rope or the second traction rope is adjusted, the limiting pin can be taken down, the connecting ring and the rotating disc are rotated, the corresponding first through hole is aligned with the second through hole, and then the first through hole and the second through hole are inserted and fixed, so that the adjusting mode is simple and quick.

As a preferred embodiment of the present invention, the auxiliary supporting mechanism further includes a fourth rotating shaft and two thigh supporting plates, both thigh supporting plates are rotatably connected with the fourth rotating shaft, the two thigh supporting plates are provided with mounting grooves, the third rotating shaft is rotatably mounted in the mounting grooves, the third rotating shaft is fixedly connected with a first limiting block, and the thigh supporting plates are fixedly connected with a second limiting block in the mounting grooves;

the second traction rope drives the lower leg supporting plate to rotate until the first limiting block contacts with the second limiting block, so that the lower leg supporting plate drives the thigh supporting plate to lift upwards.

The beneficial effects are that: when lifting the lower limb, the lower leg is generally lifted firstly, the thigh is lifted slightly again, when the lower leg supporting plate is pulled by the second traction rope, the lower leg supporting plate rotates firstly, and when the lower leg supporting plate rotates to the contact of the first limiting block and the second limiting block, the thigh supporting plate is driven by the lower leg supporting plate to lift upwards, the lower leg supporting plate and the thigh supporting plate are more attached to the lower limb of a user, and the lower limb is effectively supported.

As a preferred embodiment of the invention, a third limiting block is fixedly connected in the mounting groove of the thigh support plate, and the first limiting block is positioned between the second limiting block and the third limiting block;

when the lower leg supporting plate is put down, the first supporting block props against the third limiting block, and the lower end face of the lower leg supporting plate is in contact with the upper end face of the first limiting block.

The beneficial effects are that: the rotation angle of the lower leg supporting plate is limited through the second limiting block and the third limiting block, so that the body injury caused by overlarge rotation angle of the lower leg supporting plate is prevented; when the lower leg supporting plate is put down, the upper end face of the second limiting block is used for supporting, and the third limiting block is used for blocking the first limiting block, so that the lower leg supporting plate is kept at an upward inclined position, and the second traction rope is convenient to pull.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the orthopedic spinal post-operative back rehabilitation exercise machine of the present invention;

FIG. 2 is a schematic diagram of the traction mechanism portion and auxiliary support mechanism portion of an embodiment of the orthopedic spinal post-operative back rehabilitation exercise machine of the present invention;

FIG. 3 is an enlarged view of a partial structure at A of FIG. 2 according to the present invention;

FIG. 4 is an enlarged view of a partial structure at B of FIG. 2 according to the present invention;

FIG. 5 is a cross-sectional view of the orthopedic spinal post-operative back rehabilitation exercise machine embodiment of the present invention with the lower leg support plate and thigh support plate lowered;

fig. 6 is an enlarged view of a partial structure at C of fig. 5 according to the present invention.

The reference numerals include: the leg support plate 1, the third rotation shaft 11, the plate body 12, the limit hole 13, the spring telescopic rod 14, the first traction rope 2, the wearing part 21, the transmission assembly 3, the first rotation shaft 31, the second rotation shaft 32, the pulley 33, the take-up reel 34, the connecting ring 35, the limit pin 36, the second traction rope 4, the connecting part 41, the fourth rotation shaft 5, the thigh support plate 6, the first limit block 61, the second limit block 62 and the third limit block 63.

Detailed Description

Exemplary embodiments that embody features and advantages of the present invention will be set forth in detail in the following description. It will be understood that the invention is capable of various modifications in various embodiments, all without departing from the scope of the invention, and that the description and illustrations herein are intended to be by way of illustration only and not to be construed as limiting the invention.

In the description of the present application, the terms "first," "second," and the like are used merely for convenience in describing the present application and for simplifying the description, and do not indicate or imply that the structures referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application.

Referring to fig. 1 and 2, the embodiment discloses a rehabilitation exercise device for back after orthopaedics spine operation, which comprises a traction mechanism and an auxiliary supporting mechanism, wherein the traction mechanism comprises a first traction rope 2, a transmission assembly 3 and two second traction ropes 4, one end of the first traction rope 2 is fixedly connected with a wearing part 21, one end of the second traction rope 4 is fixedly provided with a connecting part 41, and the connecting part 41 is arranged on a lower leg supporting plate 1.

In the present embodiment, the wearing part 21 of the shoulder is used and connected to the first traction rope 2 by a buckle, and in other embodiments, a glove or a sleeve may be used as the wearing part 21 of the upper limb.

Wherein the auxiliary supporting mechanism comprises two rotatable shank supporting plates 1, and the rotation supporting point of the shank supporting plates 1 is positioned below the knee; referring to fig. 5 and 6, the lower leg support plate 1 includes a third rotation shaft 11 and a plate body 12, the plate body 12 is fixedly connected to the third rotation shaft 11, a sliding groove is formed on an upper end surface of the plate body 12, and the connecting portion 41 is slidably mounted in the sliding groove;

the plate body 12 is provided with a plurality of limiting holes 13 along the direction of the sliding groove, the limiting holes 13 are communicated with the sliding groove, the connecting part 41 is provided with a spring telescopic rod 14, the spring telescopic rod 14 passes through the corresponding limiting holes 13, and a round angle is arranged at one end of the spring telescopic rod 14 extending out of the limiting holes 13;

the spring expansion link 14 is pressed into the sliding groove, and the connecting portion 41 can slide along the sliding groove.

In this embodiment, the spring telescopic rod 14 includes a fixed rod body, a sliding sleeve and a spring, the fixed rod body is fixedly connected with the connecting portion 41, the sliding sleeve is slidably connected with the rod body and is located in the limiting hole 13, the round angle is arranged at one end of the sliding sleeve, the spring is arranged in the sliding sleeve, and the fixed rod body abuts against the spring.

Referring to fig. 5 and 6, the auxiliary supporting mechanism further includes a fourth rotating shaft 5 and two thigh supporting plates 6, wherein two thigh supporting plates 6 are both rotatably connected with the fourth rotating shaft 5, mounting grooves are formed in the two thigh supporting plates 6, the third rotating shaft 11 is rotatably mounted in the mounting grooves, a first limiting block 61 is fixedly connected to the third rotating shaft 11, and a second limiting block 62 is fixedly connected to the thigh supporting plates 6 in the mounting grooves;

the second traction rope 4 drives the lower leg supporting plate 1 to rotate until the first limiting block 61 contacts with the second limiting block 62, so that the lower leg supporting plate 1 drives the thigh supporting plate 6 to lift upwards.

The thigh supporting plate 6 is fixedly connected with a third limiting block 63 in the mounting groove, and the first limiting block 61 is positioned between the second limiting block 62 and the third limiting block 63;

when the lower leg supporting plate 1 is put down, the first supporting block abuts against the third limiting block 63, and the lower end face of the lower leg supporting plate 1 is in contact with the upper end face of the first limiting block 61.

Referring to fig. 2 to 4, the transmission assembly 3 includes a first rotating shaft 31 and a second rotating shaft 32 that are arranged in parallel, the first rotating shaft 31 is located at one side of the lower leg support plate 1 near the first traction rope 2, the second rotating shaft 32 is located between the first rotating shaft 31 and the lower leg support plate 1, a pulley 33 is fixedly connected to the first rotating shaft 31, and three winding drums 34 are fixedly installed on the second rotating shaft 32 along the axial direction; the other end of the first traction rope 2 passes through the bottom of the pulley 33 and is fixedly connected to a take-up reel 34 in the middle, the other end of the second traction rope 4 passes through the upper end face of the lower leg supporting plate 1 and is fixedly connected to a corresponding take-up reel 34, and when the lower leg supporting plate 1 is not lifted, the included angle between the lower leg supporting plate 1 and the horizontal plane is larger than 0 degrees.

Referring to fig. 2 and 4, the take-up reel 34 is fixedly connected with a connection ring 35, the connection ring 35 is provided with a plurality of first through holes along the circumferential direction, the second rotating shaft 32 is vertically provided with a second through hole, and a limiting pin 36 is installed in one of the through holes and the second through hole.

The winding direction of the winding drum 34 in the middle part is opposite to that of the winding drums 34 on the two sides.

When the wearing part 21 is positioned on the upper limb, the upper limb drives the lower leg supporting plate 1 to lift, so that the force applied by the lower limb can be reduced, and the balance is easier to keep;

when the wearing part 21 is positioned on the shoulder, the lower leg supporting plate 1 is driven to be lifted by the shoulder, so that the force required by lifting the back is increased, the exercise effect is enhanced, and the device is suitable for people with better body functions.

Wherein, the transmission assembly 3 further comprises a servo motor and a pressure sensor, the pressure sensor is arranged on the first rotating shaft 31, and an output shaft of the servo motor is fixedly connected with the second rotating shaft 32;

when the first traction rope 2 is lifted upwards, and the detection value of the pressure sensor is higher than a preset value, the servo motor drives the second rotating shaft 32 to rotate, the take-up reel 34 in the middle part pays off, and the take-up reels 34 at the two ends take up wires; when the detection value of the pressure sensor is lower than the preset range, the servo motor reversely rotates to reset the take-up reel 34.

In this embodiment, the servo motor is provided with the maximum rotation angle, and when rotating to the maximum rotation angle (at this time, both the upper limb and the shoulder are lifted to the maximum height), the servo motor stops rotating, and the detected pressure value is lower than the preset value, and the servo motor reversely rotates.

The application method and principle of the embodiment are as follows:

according to different requirements of users, different wearing parts 21 are worn, when the servo motor is not electrified, the spring telescopic rod 14 is pressed, the position of the connecting part 41 is moved, the limiting pin 36 is taken down, the connecting ring 35 and the rotating disc are rotated, the corresponding first through holes are aligned with the second through holes, and then the connecting part is inserted and fixed, so that the distance between the connecting part 41 and the take-up reel 34 can be changed, and the load on the back is adjusted;

when the device is used, when the shoulder or the upper limb is lifted upwards, the first traction rope 2 is pulled, the take-up reel 34 in the middle part is paid off, the second rotating shaft 32 rotates, the take-up reels 34 at the two ends are driven to take up wires due to the reverse winding directions, the second traction rope 4 drives the lower leg support plate 1, when the first limiting block 61 is rotated to be in contact with the second limiting block 62, the lower leg support plate 1 drives the thigh support plate 6 to lift upwards, the lower limb is supported, when the shoulder or the lower limb is put down, the lower leg support plate 1 falls down due to gravity, the second traction rope 4 is pulled, the take-up reels 34 at the two ends are paid off, and the take-up reels 34 in the middle part are wound up, so that the first traction rope 2 and the second traction rope 4 are reset;

the weight of the back can be adjusted through the connecting part 41 and the connecting ring 35, so that the utility model is suitable for different crowds, the lower limb exertion of a user is reduced through the lower leg supporting plate 1 and the thigh supporting plate 6, the upper limb or the back exertion of the user is ensured, the stability of the whole posture is ensured, and the rehabilitation effect is ensured;

when the servo motor is electrified, when the shoulder or the upper limb is lifted upwards, the first traction rope 2 is pulled upwards, the pulley 33 generates pressure on the first rotating shaft 31, when the detection value of the pressure sensor is higher than a preset value, the servo motor drives the second rotating shaft 32 to rotate, the take-up reel 34 in the middle part is used for paying off, the take-up reels 34 at the two ends are used for taking up wires, the second traction rope 4 drives the lower leg supporting plate 1, and when the first limiting block 61 is contacted with the second limiting block 62, the lower leg supporting plate 1 drives the thigh supporting plate 6 to be lifted upwards, so that the lower limb is supported; when the detection value of the pressure sensor is lower than the preset range, the servo motor reversely rotates to reset the take-up reel 34;

the leg strength is reduced by driving the servo motor, and no extra load is added to the upper limbs and the shoulders, so that the electric foot-rest is suitable for people with poor body functions.

The above embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, but any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention are intended to be within the scope of the present invention as claimed.

Claims (7)

1. The utility model provides a recovered exerciser in back behind orthopedics backbone art which characterized in that:

the device comprises a traction mechanism and an auxiliary supporting mechanism, wherein the auxiliary supporting mechanism comprises two rotatable shank supporting plates, and a rotating fulcrum of each shank supporting plate is positioned below a knee;

the traction mechanism comprises a first traction rope, a transmission assembly and two second traction ropes, one end of the first traction rope is fixedly connected with a wearing part, the wearing part is worn on an upper limb or a shoulder, one end of the second traction rope is fixedly provided with a connecting part, and the connecting part is arranged on a lower leg supporting plate;

after wearing the wearing part, when the shoulders and the upper limbs are lifted, the first traction rope is driven to pull the transmission assembly, the transmission assembly is controlled to pull the second traction rope, the second traction rope pulls the shank supporting plate to lift up around the rotating supporting point, and after the shoulders and the lower limbs are put down, the transmission assembly pulls back the first traction rope and loosens the second traction rope.

2. The orthopedic spinal post-operative back rehabilitation exerciser according to claim 1, wherein:

the transmission assembly comprises a first rotating shaft and a second rotating shaft which are arranged in parallel, the first rotating shaft is positioned at one side of the shank supporting plate, which is close to the first traction rope, the second rotating shaft is positioned between the first rotating shaft and the shank supporting plate, the first rotating shaft is fixedly connected with a pulley, and the second rotating shaft is fixedly provided with three take-up reels along the axial direction;

the other end of the first traction rope passes through the bottom of the pulley and is fixedly connected to a take-up reel at the middle part, the other end of the second traction rope passes through the upper end surface of the lower leg supporting plate and is fixedly connected to a corresponding take-up reel, and when the lower leg supporting plate is not lifted, the included angle between the lower leg supporting plate and the horizontal plane is larger than 0 degree;

the winding directions of the winding drums in the middle part are opposite to those of the winding drums at the two sides.

3. The orthopedic spinal post-operative back rehabilitation exerciser according to claim 2, wherein:

the transmission assembly further comprises a servo motor and a pressure sensor, the pressure sensor is arranged on the first rotating shaft, and an output shaft of the servo motor is fixedly connected with the second rotating shaft;

when the first traction rope is lifted upwards, the servo motor drives the second rotating shaft to rotate when the detection value of the pressure sensor is higher than a preset value, the take-up reel in the middle part pays off, and the take-up reels at the two ends take-up wires; when the detection value of the pressure sensor is lower than a preset range, the servo motor reversely rotates to reset the take-up reel.

4. The orthopedic spinal post-operative back rehabilitation exerciser according to claim 2, wherein:

the lower leg supporting plate comprises a third rotating shaft and a plate body, the plate body is fixedly connected to the third rotating shaft, a sliding groove is formed in the upper end face of the plate body, and the connecting part is slidably arranged in the sliding groove;

the plate body is provided with a plurality of limiting holes along the direction of the sliding groove, the limiting holes are communicated with the sliding groove, the connecting part is provided with a spring telescopic rod, the spring telescopic rod penetrates through the corresponding limiting holes, and a round angle is arranged at one end of the spring telescopic rod extending out of the limiting holes;

the spring telescopic rod is pressed into the sliding groove, and the connecting part can slide along the sliding groove.

5. The orthopedic spinal post-operative back rehabilitation exerciser according to claim 4, wherein:

the winding disc is fixedly connected with a connecting ring, a plurality of first through holes are formed in the connecting ring along the circumferential direction, second through holes are vertically formed in the second rotating shaft, and limiting pins are arranged in one through hole and the second through hole.

6. The orthopedic spinal post-operative back rehabilitation exerciser according to claim 4, wherein:

the auxiliary supporting mechanism further comprises a fourth rotating shaft and two thigh supporting plates, wherein the two thigh supporting plates are both in rotating connection with the fourth rotating shaft, mounting grooves are formed in the two thigh supporting plates, the third rotating shaft is rotatably mounted in the mounting grooves, a first limiting block is fixedly connected to the third rotating shaft, and a second limiting block is fixedly connected to the thigh supporting plates in the mounting grooves;

the second traction rope drives the lower leg supporting plate to rotate until the first limiting block contacts with the second limiting block, so that the lower leg supporting plate drives the thigh supporting plate to lift upwards.

7. The orthopedic spinal post-operative back rehabilitation exerciser according to claim 6, wherein:

the thigh support plate is fixedly connected with a third limiting block in the mounting groove, and the first limiting block is positioned between the second limiting block and the third limiting block;

when the lower leg supporting plate is put down, the first supporting block props against the third limiting block, and the lower end face of the lower leg supporting plate is in contact with the upper end face of the first limiting block.