JP2024005394A - Measurement device that measures reaction force in dorsiflexion motion of shoe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement device capable of correctly and simply measuring stumbling resistivity of a shoe.

SOLUTION: A measurement device X includes: a holding tool 7 that holds a shoe 1 so as to be rotatable with respect to a rotation shaft when a wearer performs plantar flexion and the dorsiflexion; and a measuring tool Y that measures a torque value applied to a rotation shaft 6. The measurement device X is configured to measure an absolute value of a difference between an initial torque value applied to the rotation shaft 6 due to a weight of the holding tool 7 in a state where the holding tool 7 does not hold the shoe 1 and a first torque value applied to the rotation shaft 6 due to weights of the shoe 1 and the holding tool 7 in a state where the holding tool 7 holds the shoe 1.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

BACKGROUND OF THE INVENTION 1. Field of the Disclosure The present disclosure relates generally to measurement devices, and specifically to devices for measuring drag during dorsiflexion of a shoe.

A wearer of shoes may fall while walking, and one of the factors is stumbling.

When walking, movements such as flexion at the hip joint, extension at the knee joint, and dorsiflexion at the ankle joint are performed. During these movements, stumbling is thought to occur if a part of the shoe other than the toe that should touch the ground comes into contact with the ground. In order to avoid stumbling, the human body performs an evasive action by moving the shoe away from the ground until the sole of the shoe touches the ground. Specifically, by lifting the knee or dorsiflexing the ankle joint, the sole of the shoe is separated from the ground.

Regarding the difficulty of tripping, the Ministry of Health, Labor and Welfare's workplace safety site (hereinafter referred to as Patent Document 1) lists the weight balance of shoes. Specifically, this is judged by how low the toes fall when the shoe is hung with a string passed through the eyelet hole closest to the heel, and shoes with low toes are said to be more likely to cause tripping.

“Workplace Safety Site”, [online], Ministry of Health, Labor and Welfare, [searched on June 20, 2020], Internet <https://anzeninfo.mhlw.go.jp/information/tentou1501_25.html>

However, the determination method described in Patent Document 1 has a problem in that even if the weight is light, it is determined that stumbling is likely to occur just because the toe side is heavy.

An object of the present disclosure is to provide a measuring device that can easily and accurately measure the resistance to tripping of shoes.

The measuring device according to the first aspect of the present disclosure measures the drag force during dorsiflexion motion of the shoe. The measuring device includes a holder that holds the shoe rotatably about a rotational axis when the wearer of the shoe performs plantar dorsiflexion, and a measuring device that measures a torque value applied to the rotational axis. Be prepared. The measuring device is configured to measure the absolute value of the difference between the initial torque value and the first torque value. The initial torque value refers to a torque value applied to the rotating shaft by the weight of the holder when the holder does not hold the shoe. The first torque value refers to a torque value applied to the rotating shaft due to the weight of the shoe and the holder when the holder holds the shoe.

According to the measuring device of the present disclosure, the trip resistance of shoes can be measured accurately and easily.

FIG. 1A is a schematic perspective view showing a measuring device according to an embodiment of the present disclosure. FIG. 1B is a schematic side view showing a measuring device according to an embodiment of the present disclosure. FIG. 2A is a schematic perspective view showing the same measuring device as above. FIG. 2B is a schematic side view showing the same measuring device as above. FIG. 3 is a schematic side view showing a shoe measured by the same measuring device. FIG. 4 is a schematic top view showing the bones of the foot arranged within the shoe. FIG. 5A is a schematic back view showing a shoe held in a retainer. FIG. 5B is a schematic top view showing the shoe held in the retainer.

Hereinafter, the configuration of a measuring device X according to an embodiment of the present disclosure will be described with reference to the drawings. The measuring device X according to this embodiment is just an example, and the configuration of the measuring device X is not limited to the following content.

1. overview

The measuring device X according to this embodiment includes a holder 7 and a measuring instrument Y, as shown in FIG. 1A.

The holder 7 is configured to hold the shoe 1 rotatably about the rotation axis 6 when the wearer of the shoe 1 plantarly flexes the ankle joint.

The measuring device Y is configured to measure the torque value applied to the rotating shaft 6.

The measuring device X is configured to measure the absolute value of the difference between the initial torque value N ₀ and the first torque value N _1c measured by the measuring device Y.

The initial torque value N ₀ (N-m) indicates the torque value applied to the rotating shaft 6 by the weight of the holder 7 when the holder 7 does not hold the shoe 1 (see FIG. 2A).

Further, the first torque value N ₁ (N-m) indicates the torque value applied to the rotating shaft 6 due to the weight of the shoe 1 and the holder 7 when the holder 7 holds the shoe 1 (see FIG. 1B).

The above-mentioned "absolute value of the difference between the initial torque value N ₀ (N-m) and the first torque value N ₁ (N-m)" is the resistance exerted by the shoe when the wearer plantar-dorsiflexes the ankle joint. It shows. Therefore, by measuring this drag force with the measuring device X, the resistance to tripping can be measured more accurately and easily than when measuring the weight balance of shoes. For example, the smaller the drag force is, the harder the shoe is to trip over, and by measuring and comparing the drag forces of a plurality of shoes, the resistance to tripping can be compared.

2. detail

The configuration of the measuring device X of this embodiment will be described in more detail below.

In explaining the measuring device X, first, the configuration of the shoe 1 to be measured will be explained.

2-1. shoes

The shoe 1 includes an upper portion 2 and a sole 3 (see FIG. 3).

The upper portion 2 is configured to wrap around the wearer's foot. The upper portion 2 includes a shoe opening 20 into which the wearer's foot is inserted. The upper portion 2 may be configured to wrap around the entire foot of the wearer, or may not wrap around a part of the foot of the wearer. For example, the toe portion of the wearer's foot may be exposed. Although the upper portion 2 does not include a plurality of eyelet holes for passing shoelaces, the present invention is not limited thereto, and may include, for example, a plurality of eyelet holes. The upper part 2 may be composed of a single member or a plurality of members. For example, the upper portion 2 may include a tongue.

The sole 3 is configured to support the wearer's foot from below, and is connected to the upper part 2. Further, the lower surface of the sole 3 is configured to be in contact with the ground.

Further, in this embodiment, when the shoe 1 is placed on a horizontal plane, a straight line connecting the tip of the toe of the shoe 1 and the rear end of the heel is projected onto the horizontal plane, and the line is defined as the horizontal center line 4 of the sole. (See Figure 3).

2-2. Measuring device

As described above, the measuring device X includes the holder 7 and the measuring instrument Y (see FIGS. 2A and 2B).

2-2-1. Holder 7

The holder 7 of this embodiment includes a holder main body 70, a rotating shaft 6, a pair of pillar parts 71 (71A, 71B), a pedestal part 72, and an arm part 73.

The holder 7 is configured to be in close contact with the upper part 2 and not move when inserted from the shoe opening 20 of the shoe 1.

The holder main body 70 of this embodiment has a shape that resembles a foot with the toe side cut off in a cross section that crosses all the first to fifth metatarsals between the Lisfranc joint and the MP joint of the foot (see FIG. 2B). . This makes it easy to hold the shoe 1 with the holder main body 70 even if the shoe is a work shoe whose toe portion is difficult to deform. The shape of the holder main body 70 is not particularly limited as long as it is configured to be in close contact with the shoe opening 20 so that the shoe 1 does not move. Preferably, the surface of the holder body 70 has low frictional resistance so that the shoe 1 can be easily attached and detached. The material of the holder main body 70 is not particularly limited, but may be made of resin, wood, or metal, for example.

The holder main body 70 is provided with a rod-shaped rotating shaft 6, as shown in FIG. 2A. The rotation shaft 6 is provided so as to protrude left and right from a portion of the holder main body 70 that corresponds to an axis (rotation shaft) when the wearer plantarly flexes the foot. The left and right protruding portions of the rotating shaft 6 may or may not be connected inside the holder main body 70. The cross-sectional shape of the rotating shaft 6 may be round, or may be a polygon having a triangular shape or more.

Generally, the axis of rotation when plantar dorsiflexing the foot is within the range of 10% to 30% of the length of the foot, based on the posterior end of the heel (as shown in Figure 4). part corresponding to the talotrochlear surface Z). Therefore, the horizontal position of the rotating shaft 6 is 10% or more and 30% of the length of the foot (the length from the rear end to the front end of the shoe 1) when the holder body 70 holds the shoe 1. It is preferably included in the following ranges. Generally, the axis of rotation when plantar dorsiflexing the foot is within a range of 20% or more and 30% or less of the length of the foot, based on the ground contact surface. Therefore, the vertical position of the rotating shaft 6 is 20 feet from the inner bottom of the shoe 1 (or the upper surface of the insole if there is an insole) when the shoe 1 is held in the holder main body 70. % or more and 30% or less.

In addition, the axis of rotation when the wearer plantar-dorsiflexes the foot is generally not parallel to the horizontal plane, but is inclined downward toward the lateral instep side of the shoe 1 (the broken line in Figure 5A and the axis of rotation (compare with axis 6). Specifically, the angle of the axis of rotation of the foot with respect to the horizontal plane is generally 20° or less. Therefore, as shown in FIG. 5A, the rotation axis 6 is preferably inclined downwardly toward the outer shell side of the shoe 1. Further, it is preferable that the angle of inclination of the rotating shaft 6 with respect to the horizontal plane is 20° or less.

Generally, the center line of the wearer's foot (corresponding to the horizontal center line 4 of the sole) does not completely coincide with the front-rear direction (the broken line indicating the front-rear direction in FIG. 5B and the horizontal center line 4 of the sole Comparison), the axis of rotation during plantar dorsiflexion is also tilted backwards on the lateral carapace side (generally less than 10 degrees, although there are individual differences). Therefore, it is preferable that the rotating shaft 6 also be inclined toward the rear on the lateral shell side, as shown in FIG. 5B. Specifically, it is preferable that the angle of inclination of the rotating shaft 6 with respect to a vertical plane (a plane perpendicular to the horizontal plane and along the front-rear direction) is 10 degrees or less.

The material of the rotating shaft 6 is not particularly limited, but may be made of resin, wood, or metal, for example. The rotating shaft 6 may be made of the same material as the holder main body 70, or may be made of a different material. The rotating shaft 6 may be an integral member with the holder main body 70, or may be a separate member.

The pedestal portion 72 is a rectangular plate-shaped member, as shown in FIG. 2A. The column portion 71 stands vertically from the pedestal portion 72. The holder main body 70 is arranged between the pair of pillar parts 71A and 71B. The base portion 72 and the column portion 71 may be an integral member or may be separate members. Moreover, the material of the pedestal part 72 and the pillar part 71 is not particularly limited, and may be made of resin, wood, or metal.

In the holding part 7 of this embodiment, the rotating shaft 6 is inserted into each through hole provided in the upper part of the column part 71A and the upper part of the column part 71B. Thereby, the holder main body 70 is arranged between the column part 71A and the column part 71B. Further, by inserting the rotating shaft 6 into the through hole, the holder main body 70 becomes rotatable about the shaft when the wearer plantarly flexes the foot. The cross-sectional shape of the through hole is not particularly limited as long as the rotating shaft 6 is rotatable. Although the columnar portion 71 of this embodiment is provided with a through hole, the present invention is not limited to this. For example, a groove may be provided at the upper end of the columnar portion 71, and the rotating shaft 6 may be disposed within this groove. . Further, the cross-sectional shape of the groove is not particularly limited as long as the rotating shaft 6 is rotatable.

The arm portion 73 is a U-shaped member when viewed from the side. The arm portion 73 includes an upper projecting portion 730 extending upward from the upper surface of the holder main body 70, an arm main body 731 extending forward from the upper end of the upper projecting portion 730, and a lower projecting portion extending downward from the front end of the arm main body 731. portion 732. As will be described later, the arm portion 73 of this embodiment is configured such that the mounting table of the measuring instrument Y is pushed by the lower end portion of the lower projecting portion 731. The material of the arm portion 73 is not particularly limited, but may be made of resin, wood, or metal, for example.

2-2-2. Measuring instrument Y

The measuring instrument Y of this embodiment includes a measuring instrument main body Y0 and a spacer Y1 (see FIG. 2B).

The measuring instrument main body Y0 is a scale capable of measuring the mass of an object. The measuring instrument main body Y0 is, for example, a digital scale, but is not particularly limited, and may be an analog scale. The measuring instrument main body Y0 includes a mounting table on which a measurement target is placed, and a spacer Y1, which will be described later, is placed on this table.

The spacer Y1 is a member for matching the height of the rotating shaft 6 and the height of the mounting table of the measuring instrument main body Y0. Therefore, by adjusting the size of the spacer Y1, the heights of the column parts 71A and 71B of the holding part 7, and the pedestal part 72, the height of the rotating shaft 6 and the height of the mounting table may be matched.

The spacer Y1 is arranged on the mounting table of the measuring instrument main body Y0. The spacer Y1 may simply be placed on the mounting table, or may be fixed. Although the spacer Y1 of this embodiment is a rectangular frame-shaped member as shown in FIG. 2A, it is not limited to this, and may be plate-shaped or box-shaped, for example. Since the spacer Y1 has a frame shape, when the shoe 1 is held by the holder 7, the toe portion of the shoe 1 can be inserted into the frame of the spacer Y1. The spacer Y1 includes a contact member Y2 configured to come into contact with the lower projecting portion 732 of the arm portion 73. The contact member Y2 of this embodiment is a cylindrical member provided at the top of the spacer Y1. The shape of the contact member Y2 is not particularly limited, and may be, for example, a prismatic shape. For example, the contact member Y2 may be a part of the intermediate member Y1. For example, the intermediate member Y1 and the lower protruding portion 732 of the extension portion 73 may be in direct contact. The material of the intermediate member Y1 is not particularly limited, and may be resin, wood, or metal.

2-3. Measuring method

A measurement method using the measurement device X of this embodiment will be explained.

(1) Measurement of initial torque value

First, as shown in FIG. 2A, in a state where the holder 7 does not hold the shoe 1, the torque value (initial torque value N ₀ , value is N−m) related to the rotating shaft 6 is measured.

In the state shown in FIG. 2A, the rotating shaft 6 is supported by the column parts 71A and 71B and is rotatably held. Furthermore, the load related to the rotation shaft 6 of the holder 7 is applied to the measuring instrument main body Y0 via the arm portion 73 and the spacer Y. Therefore, based on the display (scale) of the measuring instrument body Y0 in the state shown in FIG. 2A, it is possible to measure the drag force applied when rotating the holder 7 in a state where the holder 7 does not hold the shoe 1. This initial torque value N ₀ represents the resistance force applied to the axis of rotation of the foot when the wearer plantarly flexes the foot without wearing the shoe 1 . Specifically, the initial torque value _N0 can be calculated by multiplying the display (mass) of the measuring instrument main body Y0 by the weight acceleration and the distance from the rotating shaft 6 to the tip of the lower protruding portion 732.

(2) Measurement of first torque value

Next, as shown in FIG. 1A, with the shoe 1 held by the holder 7, the torque value (first torque value N ₁ , the value is Nm) related to the rotating shaft 6 is measured. In this state, the shoe 1 is kept horizontal by the holder 7. Note that "horizontal" here means a state in which the horizontal center line 4 of the sole is parallel to the horizontal plane. Further, it is preferable that the holder 7 is similarly kept horizontal when measuring the initial torque value _N0 .

In the state shown in FIG. 1A, the load applied to the rotating shaft 6 by the holder 7 and the shoe 1 is applied to the measuring instrument main body Y0 via the arm part 73 and the spacer Y. Therefore, in the state shown in FIG. Based on the display (scale) on the main body Y0, the drag force applied when rotating the holder 7 while the holder 7 is holding the shoe 1 can be measured. This first torque value _N1 represents the drag force applied to the rotational axis of the foot when the wearer plantarly flexes the foot while wearing the shoe 1. Specifically, the first torque value _N1 can be calculated by multiplying the display (mass) of the measuring instrument main body Y0 by the weight acceleration and the distance from the rotating shaft 6 to the tip of the lower projecting portion 732.

(3) Calculation of the absolute value of the difference between the initial torque value and the first torque value

Next, the absolute value of the difference between the initial torque value N ₀ and the first torque value N ₁ determined in (1) and (2) above is determined.

The absolute value of the difference between the initial torque value N ₀ and the first torque value N ₁ represents the drag force exerted on the foot by “shoe 1 only” when the wearer plantarly flexes the foot.

For example, by preparing a plurality of different shoes 1 and measuring and comparing the above-mentioned drag forces using these shoes 1, it is possible to understand which shoe 1 has the smallest drag force when plantar dorsiflexing the foot. . In addition, a small resistance force when plantar dorsiflexing the foot means that the person is less likely to stumble while walking. Therefore, by measuring and comparing the drag forces of a plurality of different shoes 1, it is possible to understand which shoe 1 is less likely to trip.

3. Variations

The configuration of the measuring device X is not limited to the above-mentioned configuration.

The measuring device X is configured such that the holder 7 and the measuring instrument Y are in contact with each other. Specifically, the tip of the lower projecting portion 732 of the arm portion 73 is in contact with the upper surface of the contact member Y2 of the spacer Y1 of the measuring instrument Y. Therefore, it is preferable to adjust the sizes of the column part 71, the pedestal part 72, and the spacer Y1 according to the height of the mounting table of the measuring instrument main body Y0.

Although the above-mentioned holder 7 includes the rod-shaped rotating shaft 6, the present invention is not limited to this. For example, in case the shoe 1 has a high opening such as a boot, the holder 7 may include a crank-shaped rotating shaft 6 with a offset.

The holder body 70 described above has, for example, a certain volume, but is not limited thereto. The holder main body 70 may have a deformation mechanism that increases the volume when inserted into the shoe 1.

The above-mentioned measuring device Y includes the spacer Y1, but is not limited thereto. For example, if the height of the mounting portion of the measuring instrument main body Y0 is the same as the height of the rotating shaft 6, the spacer Y1 may not be provided. Furthermore, for example, the holder main body 70, rotating shaft 6, column part 71, pedestal part 72, and arm part 73 have different sizes so that the shape of the holder 7 can be changed according to the size of the shoe 1. Replacement parts may be available.

1 Shoes 6 Rotating shaft 7 Holder X Measuring device Y Measuring instrument

Claims (6)

A measuring device for measuring drag force during dorsiflexion motion of a shoe,
a holder that holds the shoe rotatably about a rotation axis when the wearer of the shoe performs plantar dorsiflexion;
A measuring device that measures a torque value related to the rotating shaft,
The initial torque value applied to the rotating shaft by the weight of the holder when the holder is not holding the shoe, and the weight of the shoe and the holder when the holder is holding the shoe. It is characterized in that it is configured to measure the absolute value of the difference between the first torque value and the first torque value applied to the rotating shaft. The measuring device according to claim 1,
It is characterized in that the rotation axis is inclined downwardly toward the outer instep side of the shoe. The measuring device according to claim 2,
It is characterized in that the angle of inclination of the rotation axis with respect to a horizontal plane is 20 degrees or less. The measuring device according to claim 1,
It is characterized in that the rotation axis is inclined toward the rear of the outer instep side of the shoe. The measuring device according to claim 4,
It is characterized in that the angle of inclination of the rotation axis with respect to a vertical plane is 10 degrees or less. The measuring device according to claim 1,
The first torque value is measured with the shoe in a horizontal state.

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