Foot joint bottom dorsal flexion training device

Abstract

To provide a foot joint bottom dorsal flexion training device which allows a user to do exercise in a broad movable area by putting the heels down to a sufficient dorsal flexion angle, and to perform plantar flexion exercise at a high speed by reducing exercise load.SOLUTION: A foot joint bottom dorsal flexion training device 100 includes a body section 10 and a pedal section 20. The body section 10 includes a pedestal part 11, a bottom 12, an energization part 14, and a rotation support part 15. The pedal section 20 includes a base end part 21, a central part 22, and a tip part 23. The pedal section 20 is configured to be positioned in a state of being rotated around a rotation shaft 15b, the tip part 23 to the pedestal part 11 at the bottom 12 side in an opposite direction where the pedestal part 11 and the bottom 12 are opposed to each other. An energization part 14 is configured to energize the pedal section 20 to the bottom 12 at the pedestal part 11 side in the opposite direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an ankle joint plantar flexion and dorsiflexion training device. [Background technology]

[0002] Ankle plantar flexion function is an important lower limb function related to various athletic performances such as walking, running, and jumping. Pushing off by plantar flexion of the ankle during walking contributes to the generation of forward propulsion. In addition to plantar flexion muscle strength, plantar flexion velocity is also an important factor in ankle plantar flexion function. Plantar flexion velocity is the joint angular velocity when plantar flexion is performed as quickly as possible without load. Plantar flexion velocity may be a more important function for athletic performance than plantar flexion muscle strength.

[0003] To improve plantar flexion speed, plantar flexion exercises with a wide range of motion and at high speed are necessary. Calf raises (heel raising exercise) are a typical plantar flexion strength training exercise. A wide range of motion and high speed calf raises can improve ankle plantar flexion function (muscle strength and movement speed). Improvement in ankle plantar flexion function is expected to lead to improved athletic performance. A typical calf raise is an exercise in which, while standing on a flat floor, the heel is raised high and then lowered repeatedly. Calf raises using a step are an exercise in which the heel is raised on a step, and the heel is lowered as far as possible and then raised high and then repeatedly lowered.

[0004] For example, Utility Model Registration No. 3230391 (Patent Document 1) describes a tiptoe standing facilitating exercise device that is designed to promote tiptoe standing by pushing up the heel with a compression coil spring from under the heel when standing on tiptoe. Specifically, a sole mounting plate is provided on a base via a compression coil spring. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility Model Registration No. 3230391 Summary of the Invention [Problem to be solved by the invention]

[0006] In a typical calf raise, the heel is lowered while standing on a flat floor, so it is difficult to lower the heel to a sufficient dorsiflexion angle. Therefore, it is difficult to exercise with a wide range of motion. In a calf raise using a step, the exercise load is large, so plantar flexion exercise at high speed is difficult. In the facilitation exerciser described in the above publication, a plantar mounting plate is provided on the base via a compression coil spring, so it is difficult to lower the heel to a sufficient dorsiflexion angle. Therefore, it is difficult to exercise with a wide range of motion.

[0007] The present invention has been made in consideration of the above problems, and its purpose is to provide an ankle joint plantar flexion and dorsiflexion training device that allows exercise over a wide range of motion by lowering the heel to a sufficient dorsiflexion angle, and allows plantar flexion exercise to be performed at high speed by reducing the exercise load. [Means for solving the problem]

[0008] The ankle joint plantar flexion training device of the present invention includes a main body and a pedal connected to the main body. The main body includes a base, a bottom facing the base, a biasing unit configured to bias the pedal, and a rotation support configured to rotatably support the pedal. The rotation support includes a bearing and a rotation shaft rotatably supported by the bearing. The pedal includes a base end supported by the rotation shaft, a central portion connected to the base end, and a tip end disposed on the opposite side of the central portion to the base end. The pedal is configured to position the tip end on the bottom side of the base in a facing direction in which the base and the bottom face each other when rotated about the rotation shaft. The biasing unit is configured to bias the pedal toward the base with respect to the bottom in a facing direction in which the base and the bottom face each other. Effect of the Invention

[0009] According to the ankle joint plantar flexion and dorsiflexion training device of the present invention, by lowering the heel to a sufficient dorsiflexion angle, plantar flexion exercise can be performed over a wide range of motion, and by reducing the exercise load, plantar flexion exercise can be performed at high speed. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a schematic configuration of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment; [Diagram 2] 1 is a front view showing a schematic configuration of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment; [Diagram 3] FIG. 1 is a rear view showing a schematic configuration of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment. [Figure 4] 1 is a side view showing a schematic configuration of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment; [Diagram 5] 1 is a cross-sectional view showing a schematic configuration of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment. FIG. [Figure 6] FIG. 1 is a cross-sectional view showing a schematic configuration of a first modified example of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment. [Figure 7] FIG. 13 is a rear view showing a schematic configuration of a modified example 2 of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment. [Figure 8] FIG. 13 is a side view showing a schematic configuration of a modified example 2 of an ankle joint plantar flexion and dorsiflexion training device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference characters unless otherwise specified, and the description thereof will not be repeated.

[0012] The configuration of an ankle joint plantar and dorsiflexion training device 100 according to an embodiment will be described with reference to Figs. 1 to 5. As shown in Fig. 1, the ankle joint plantar and dorsiflexion training device 100 according to an embodiment is for improving the ankle joint plantar and dorsiflexion function. The ankle joint plantar and dorsiflexion training device 100 includes a main body section 10 and a pedal section 20. The pedal section 20 is connected to the main body section 10. Fig. 5 shows the state in which the pedal section 20 is rotating.

[0013] As shown in FIG. 1 and FIG. 2, the main body 10 includes a base 11, a bottom 12, a side 13, a biasing portion 14, and a rotation support portion 15. The base 11 is configured so that the toes of the user's foot can be placed on it. The base 11 is configured in a plate shape. The base 11 includes a top surface 11a. The top surface 11a may have a non-slip function. The bottom 12 is configured to face the base 11. The bottom 12 is configured in a plate shape. The bottom 12 includes a bottom surface 12a. The bottom 12 includes a first portion 121 and a second portion 122. The first portion 121 and the second portion 122 are disposed with a gap therebetween. The side 13 is configured to connect the base 11 and the bottom 12. The side 13 is configured in a plate shape.

[0014] The biasing unit 14 is configured to bias the pedal unit 20. The biasing unit 14 is configured to bias the pedal unit 20 toward the base unit 11 with respect to the bottom unit 12 in the opposing direction in which the base unit 11 and the bottom unit 12 face each other. The biasing unit 14 is configured to assist plantar flexion. The biasing unit 14 is configured to bias the pedal unit 20 in the dorsiflexion direction.

[0015] 2 and 3, the biasing portion 14 includes a torsion spring 14a and a shaft 14b. The torsion spring 14a is configured to twist in accordance with the rotation of the pedal portion 20. The shaft 14b is configured to support the torsion spring 14a.

[0016] The torsion spring 14a includes a wound portion 14a1 and an extending portion 14a2. The extending portion 14a2 is configured to extend radially outward from the wound portion 14a1. The shaft 14b is inserted through the torsion spring 14a. The torsion spring 14a is configured such that the extending portion 14a2 biases the pedal portion 20 when the shaft 14b is inserted through the wound portion 14a1 of the torsion spring 14a. The torsion spring 14a is configured to twist in the circumferential direction of the shaft 14b. In this embodiment, the shaft 14b is fixed to the side portion 13. Specifically, both ends of the shaft 14b are fixed to each of the pair of side portions 13.

[0017] 3 and 4, shaft 14b is disposed between rotating shaft 15b and bottom part 12 in the opposing direction in which base part 11 and bottom part 12 face each other. Shaft 14b is disposed below rotating shaft 15b when ankle joint plantar flexion training device 100 is placed on the floor surface.

[0018] In this embodiment, the torsion spring 14a is a double torsion spring. The winding portion 14a1 includes a first winding portion 14a11 and a second winding portion 14a12. The second winding portion 14a12 is arranged next to the first winding portion 14a11 in the axial direction of the shaft 14b.

[0019] The extending portion 14a2 includes a first extending portion 14a21 and a second extending portion 14a22. The first extending portion 14a21 is connected to the first winding portion 14a11. The second extending portion 14a22 is connected to the second winding portion 14a12.

[0020] Torsion spring 14a includes connecting portion 14a3. Connecting portion 14a3 is configured to connect first wound portion 14a11 and second wound portion 14a12. First extending portion 14a21 is disposed on the opposite side of connecting portion 14a3 with respect to first wound portion 14a11 in the axial direction. Second extending portion 14a22 is disposed on the opposite side of connecting portion 14a3 with respect to second wound portion 14a12 in the axial direction.

[0021] As shown in FIG. 3 and FIG. 5, the biasing portion 14 includes a support portion 14c. The support portion 14c is configured to support the connecting portion 14a3. The support portion 14c has a male thread portion 14c1, a female thread portion 14c2, and a base 14c3. The female thread portion 14c2 is configured to screw into the male thread portion 14c1. The biasing portion 14 is configured to be able to change the biasing force of the torsion spring 14a by the female thread portion 14c2 moving relative to the male thread portion 14c1 supported by the base 14c3 in a state in which the female thread portion 14c2 is in contact with the connecting portion 14a3. In this embodiment, the base 14c3 is fixed to the bottom portion 12.

[0022] As shown in Fig. 4, the rotation support portion 15 is configured to rotatably support the pedal portion 20. The rotation support portion 15 includes a bearing portion 15a and a rotation shaft 15b. The rotation shaft 15b is rotatably supported by the bearing portion 15a. In this embodiment, the side portion 13 includes the bearing portion 15a.

[0023] 4 and 5, the pedal portion 20 is configured to allow a user's heel to rest on it. The pedal portion 20 includes a front surface 20a and a rear surface 20b. The front surface 20a may have an anti-slip function.

[0024] The pedal section 20 includes a base end section 21, a central section 22, and a tip section 23. The base end section 21 is disposed at the base end of the pedal section 20. The base end section 21 is supported by the rotating shaft 15b. The rotating shaft 15b is inserted into the base end section 21. The central section 22 is connected to the base end section 21. The central section 22 is disposed between the base end section 21 and the tip section 23. The tip section 23 is disposed on the opposite side of the central section 22 to the base end section 21. The tip section 23 is disposed at the tip of the pedal section 20.

[0025] The pedal section 20 is configured to position the tip section 23 on the bottom section 12 side with respect to the base section 11 in the opposing direction in which the base section 11 and the bottom section 12 oppose each other when rotated around the rotation shaft 15b. The pedal section 20 is configured to increase the distance from the bottom section 12 from the base end section 21 toward the tip section 23 when the pedal section 20 is biased by the biasing section 14 when the heel of the user is not placed on the pedal section 20. The pedal section 20 is configured to be rotatable around the rotation shaft 15b so that the distance from the bottom section 12 decreases from the base end section 21 toward the tip section 23 when the heel of the user is placed on the pedal section 20 and the heel is lowered. The rotation angle of the pedal section 20 is, for example, 55° or more upward and 30° or less downward.

[0026] The pedal portion 20 includes a contact portion 24. The contact portion 24 is configured to come into contact with the extension portion 14a2 of the torsion spring 14a. The contact portion 24 is attached to the rear surface 20b. The contact portion 24 is disposed in the central portion 22 of the pedal portion 20. The contact portion 24 is configured such that the distance from the rear surface 20b increases from the base end portion 21 toward the tip end portion 23. In other words, the contact portion 24 is inclined.

[0027] The pedal section 20 is not separated so as to move separately for the left and right feet, but is configured so that both feet are plantar flexed simultaneously to raise the heels.

[0028] The operation of the ankle joint plantar flexion and dorsiflexion training device 100 according to the embodiment will be described with reference to Figs.

[0029] In the ankle joint plantar flexion training device 100 according to the embodiment, the user places the toes on the base 11, the heels on the pedal 20, and then the heels are lowered, causing the pedal 20 to rotate. The pedal 20 rotates around the rotation axis 15b so that the tip 23 is positioned on the bottom 12 side of the base 11 in the opposing direction in which the base 11 and the bottom 12 face each other. In other words, the pedal 20 rotates around the rotation axis 15b so that the tip 23 is positioned lower than the base 11. This allows the heel to be lowered to a sufficient dorsiflexion angle. This allows for a wide range of motion (plantar flexion).

[0030] In addition, the biasing unit 14 biases the pedal unit 20 toward the base unit 11 with respect to the bottom unit 12 in the opposing direction in which the base unit 11 and the bottom unit 12 face each other. In other words, the biasing unit 14 biases the pedal unit 20 upward. This assists heel lifting by the biasing unit 14. This makes it possible to lift the heel easily and quickly. This makes it possible to perform plantar flexion at a high speed by reducing the exercise load.

[0031] Next, the effects of the ankle joint plantar flexion and dorsiflexion training device 100 according to this embodiment will be described.

[0032] According to the ankle joint plantar and dorsiflexion training device 100 of this embodiment, the pedal part 20 is configured to position the tip part 23 on the bottom part 12 side with respect to the base part 11 in the opposing direction in which the base part 11 and the bottom part 12 are opposed to each other when rotated around the rotation axis 15b. Therefore, it is possible to lower the heel to a sufficient dorsiflexion angle. Therefore, it is possible to exercise in a larger dorsiflexion range of motion. Therefore, it is possible to exercise in a wide range of motion. In addition, the biasing part 14 is configured to bias the pedal part 20 toward the base part 11 side with respect to the bottom part 12 in the opposing direction in which the base part 11 and the bottom part 12 are opposed to each other. Therefore, it is possible to easily and quickly lift the heel by assisting heel lift from below. Therefore, it is possible to perform plantar flexion exercise at a high speed by reducing the exercise load.

[0033] According to the ankle joint plantar and dorsiflexion training device 100 of this embodiment, the torsion spring 14a is configured such that the extension 14a2 biases the pedal section 20 with the shaft 14b inserted through the winding section 14a1 of the torsion spring 14a. When a cylindrical compression spring is placed below the pedal section 20 as in Patent Document 1, the winding sections of the cylindrical compression spring overlap each other, so that a large stroke cannot be obtained. In addition, a cone-shaped compression spring can prevent the winding sections from overlapping each other, but the assist force is insufficient. In contrast, in the ankle joint plantar and dorsiflexion training device 100 of this embodiment, the torsion spring 14a provides a sufficient stroke and a sufficient assist force.

[0034] According to the ankle joint plantar flexion training device 100 of this embodiment, the shaft 14b is disposed between the rotating shaft 15b and the bottom part 12 in the opposing direction in which the base part 11 and the bottom part 12 face each other. This allows the torsion spring 14a to constantly generate torque toward the base part 11. Note that in order to efficiently transmit the torque of the torsion spring 14a and smoothly rotate the pedal part 20, it is desirable that the distance between the shaft 14b and the rotating shaft 15b be slightly larger than the outer coil diameter of the torsion spring 14a.

[0035] According to the ankle joint plantar flexion training device 100 of this embodiment, the first extension portion 14a21 is disposed on the opposite side of the first winding portion 14a11 from the connecting portion 14a3 in the axial direction. The second extension portion 14a22 is disposed on the opposite side of the second winding portion 14a12 from the connecting portion 14a3 in the axial direction. Therefore, the pedal portion 20 can be biased in a well-balanced manner in the axial direction by the first extension portion 14a21 and the second extension portion 14a22. Since the shaft 14b of the torsion spring 14a and the rotation shaft 15b of the pedal portion 20 are misaligned, if the extension portion 14a2 of the torsion spring 14a and the contact portion 24 of the pedal portion 20 are fixed, the pedal portion 20 cannot rotate smoothly. Therefore, the extension portion 14a2 of the torsion spring 14a and the contact portion 24 of the pedal portion 20 are not fixed to each other.

[0036] According to the ankle joint plantar flexion training device 100 of this embodiment, the biasing part 14 is configured so that the biasing force of the torsion spring 14a can be changed by moving the female threaded part 14c2 relative to the male threaded part 14c1 supported by the base 14c3 with the female threaded part 14c2 in contact with the connecting part 14a3. This makes it possible to adjust the biasing force of the torsion spring 14a.

[0037] According to the ankle joint plantar flexion training device 100 of this embodiment, the contact portion 24 of the pedal portion 20 is configured so that the distance from the back surface 20b increases from the base end portion 21 toward the tip end portion 23. This makes it possible to suppress interference between the pedal portion 20 and the extension portion 14a2 of the torsion spring 14a.

[0038] According to the ankle joint plantar flexion training device 100 of this embodiment, the pedal unit 20 is not divided so that the left and right feet move separately, but is configured to plantar flex both feet simultaneously to raise the heels. If the pedal unit 20 is configured to raise the heels of one foot at a time independently, most of the weight is placed on the foot that is not lifting the heel, and almost none is placed on the foot that is lifting the heel, resulting in a small training effect. Since the pedal unit 20 is configured as a single plate so that the heels of both feet are lifted simultaneously, the training effect is large.

[0039] Next, a first modified example of the ankle joint plantar flexion and dorsiflexion training device 100 according to the embodiment will be described with reference to Fig. 6. Fig. 6 shows a state in which the pedal portion 20 is rotating.

[0040] In the first modification of the ankle joint plantar flexion training device 100 according to the embodiment, the biasing unit 14 includes a cylinder portion 14d. The cylinder portion 14d is configured to support the connecting portion 14a3. The cylinder portion 14d is configured to bias the connecting portion 14a3. The biasing unit 14 is configured such that the biasing force of the torsion spring 14a can be changed by the cylinder portion 14d biasing the connecting portion 14a3.

[0041] The cylinder portion 14d includes a housing 14d1 and a compression spring 14d2. The compression spring 14d2 is disposed in the housing 14d1. The compression spring 14d2 is configured to bias an end of the torsion spring 14a. The cylinder portion 14d includes an adjustment mechanism 14d3. The adjustment mechanism 14d3 is configured to be able to adjust the repulsive force of the compression spring 14d2. The adjustment mechanism 14d3 may include, for example, a bolt and be configured to compress the compression spring 14d2 by tightening the bolt.

[0042] The cylinder portion 14d is attached to the fixed portion 14e via a fixed shaft 14f. The cylinder portion 14d is configured to be rotatable about the fixed shaft 14f. In this embodiment, the fixed portion 14e is fixed to the base portion 11.

[0043] In the first modification of the ankle joint plantar flexion training device 100 according to the embodiment, the user places the toes on the base 11, and the heel on the pedal 20. When the heel is lowered, the pedal 20 rotates. When the pedal 20 is lowered below horizontal, a force is generated that rotates the torsion spring 14a. The torsion spring 14a rotates, and the end of the torsion spring 14a moves in a direction that presses the compression spring 14d2 of the cylinder 14d. This relieves the upward torque of the torsion spring 14a, and the force required to lower the pedal 20 downward is reduced.

[0044] According to the first modification of the ankle joint plantar flexion training device 100 of the present embodiment, the biasing unit 14 is configured to change the biasing force of the torsion spring 14a by the cylinder unit 14d biasing the connecting unit 14a3. Therefore, the upward torque of the torsion spring 14a is alleviated, so that it is possible to reduce the force required to lower the pedal unit 20 downward. In addition, the repulsive force of the compression spring 14d2 makes it possible to suppress abrupt rotation of the torsion spring 14a. Furthermore, the repulsive force of the compression spring 14d2 makes it possible to exert an assisting force when the torsion spring 14a rotates upward. In addition, the repulsive force of the compression spring 14d2 can be adjusted by the adjustment mechanism 14d3.

[0045] Next, a second modified example of the ankle joint plantar flexion and dorsiflexion training device 100 according to the embodiment will be described with reference to Figs.

[0046] In the second modification of the ankle joint plantar flexion training device 100 according to the embodiment, the contact portion 24 is configured to be columnar or cylindrical. The contact portion 24 is disposed so that the extension portion 14a2 of the torsion spring 14a intersects with the axial direction of the contact portion 24. The contact portion 24 is attached to the back surface 20b by an attachment member.

[0047] According to the second modification of the ankle joint plantar flexion training device 100 of the embodiment, the contact part 24 is configured in a columnar or cylindrical shape and is arranged so that the extension part 14a2 of the torsion spring 14a and the axial direction of the contact part 24 intersect. This makes it possible to suppress interference between the pedal part 20 and the extension part 14a2 of the torsion spring 14a. In addition, the cost can be reduced compared to the contact part 24 shown in Figs. 3 and 4.

[0048] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0049] 10 main body portion, 11 base portion, 12 bottom portion, 13 side portion, 14 biasing portion, 14a torsion spring, 14a1 winding portion, 14a11 first winding portion, 14a12 second winding portion, 14a2 extension portion, 14a21 first extension portion, 14a22 second extension portion, 14a3 connecting portion, 14b shaft, 14c support portion, 14c1 male thread portion, 14c2 female thread portion, 14c3 base, 14d cylinder portion, 14d1 housing, 14d2 compression spring, 14d3 adjustment mechanism, 14e fixed portion, 14f fixed shaft, 15 rotation support portion, 15a bearing portion, 15b rotation shaft, 20 pedal portion, 21 base end portion, 22 center portion, 23 tip portion, 24 Contact area, 100 ankle plantar flexion and dorsiflexion training device.

Claims

1. A main body portion, a pedal portion connected to the main body portion, the main body portion includes a base portion, a bottom portion facing the base portion, a biasing portion configured to bias the pedal portion, and a rotation support portion configured to rotatably support the pedal portion, The rotation support portion includes a bearing portion and a rotation shaft rotatably supported by the bearing portion, the pedal portion includes a base end supported by the rotating shaft, a central portion connected to the base end, and a tip end disposed on the opposite side of the base end with respect to the central portion, and is configured such that, when rotated around the rotating shaft, the tip end is positioned on the bottom side with respect to the base portion in a direction in which the base portion and the bottom portion face each other, An ankle joint plantar flexion and dorsiflexion training device, wherein the biasing portion is configured to bias the pedal portion toward the base portion relative to the bottom portion in the opposing direction in which the base portion and the bottom portion oppose each other.

2. The biasing portion includes a torsion spring and a shaft configured to support the torsion spring, The torsion spring includes a winding portion and an extension portion configured to extend radially outward from the winding portion, 2. The ankle joint plantar flexion and dorsiflexion training device according to claim 1, wherein the torsion spring is configured such that the extension portion biases the pedal portion when the shaft is inserted through the wound portion of the torsion spring.

3. The ankle joint plantar flexion and dorsiflexion training device according to claim 2 , wherein the axis is disposed between the rotation axis and the bottom portion in the opposing direction in which the base portion and the bottom portion oppose each other.

4. The winding portion includes a first winding portion and a second winding portion disposed alongside the first winding portion in the axial direction of the shaft, the extension portion includes a first extension portion connected to the first winding portion and a second extension portion connected to the second winding portion, the torsion spring includes a connecting portion configured to connect the first wound portion and the second wound portion; the first extending portion is disposed on an opposite side of the first winding portion from the connecting portion in the axial direction, The ankle joint plantar flexion and dorsiflexion training device according to claim 2 , wherein the second extending portion is disposed on an opposite side of the second winding portion from the connecting portion in the axial direction.

5. The biasing portion includes a support portion configured to support the connecting portion, The support portion has a male threaded portion, a female threaded portion configured to screw into the male threaded portion, and a base configured to support the male threaded portion, 5. The ankle joint plantar flexion training device according to claim 4, wherein the biasing portion is configured to be able to change the biasing force of the torsion spring by moving the female threaded portion relative to the male threaded portion supported by the base while the female threaded portion is in contact with the connecting portion.

6. the biasing portion includes a cylinder portion configured to support the connecting portion, The cylinder portion is configured to bias the connecting portion, 5. The ankle joint plantar flexion training device according to claim 4, wherein the biasing portion is configured so that the biasing force of the torsion spring can be changed by the cylinder portion biasing the connecting portion.

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