JP7403051B1 - footwear - Google Patents

Abstract

[Problem] To provide footwear that enables a player to stably operate the pedals as intended when playing the piano, thereby reducing the burden on the feet. [Solution] Footwear 1 according to the present invention has an upper 2 and a sole 3, and the direction connecting the tip of the toe side and the rear end of the heel side of the footwear 1 is the front-back direction, and the direction perpendicular to this is the left-right direction. A plurality of grooves 6 extending in the front-rear direction are formed in a line in the left-right direction on the back surface of the sole 3 on the toe side. [Selection diagram] Figure 1

Description

The present invention relates to footwear suitable for playing the piano.

As footwear for playing the piano, the shoes for playing the piano disclosed in Patent Document 1, which was invented by the present inventor, have been put into practical use and have been adopted by many pianists.

Patent No. 5470498

A right pedal, a middle pedal, and a left pedal are provided at the bottom of the piano body. For example, on a grand piano, the right pedal is a damper pedal that sustains the piano sound, and the middle pedal is a sostenuto pedal that releases only the damper of the pressed key from the strings, leaving only that sound with a lingering sound. , the left pedal is a shift pedal that allows you to subtly change the tone by shifting not only the volume but also the position of the strings. When the player steps on this pedal while playing, a corresponding pedal effect can be obtained.

The piano player should adjust the height of the chair and sit on the chair so that the angle of the fingers and the posture of the body are correct in relation to the piano keys, and the inner part of the foot should be slightly extended from the base of the big toe and index finger of the right foot. Pedaling is performed by placing footwear on the pedals so that it hits about one-third to one-fourth of the pedals. Piano players must maintain an inclined position with the heel of their footwear touching the floor and the toes raised to the pedal position. Then, when you press the pedal, you instantly press it all the way to the bottom, and when you raise the pedal, you instantly return it to its original position.

For example, if you play a Chopin waltz that lasts 5 minutes, you will need to press the pedal about 200 times on average. If you play continuously for 60 minutes, you will need to press the pedal a total of about 2,400 times. As described above, pedaling operations when playing the piano place a heavy burden on the feet. As a result, riders often end up having to take breaks due to calluses, cramps, or foot pain on the part of their feet that press the pedals. No attempt has been made so far to reduce the burden on the feet during pedaling. Incidentally, pedaling puts 5kg to 7kg of force on the legs, which is said to have an impact on children's bone development.

The present invention has been made in view of the above circumstances, and in particular, provides footwear that allows the performer to operate the pedals in a stable manner as intended, thereby reducing the burden on the feet when playing the piano. The purpose is to provide

In order to achieve the above object, the footwear according to the present invention has an upper and a sole, and the direction connecting the tip of the toe side and the rear end of the heel side of the footwear is the front-rear direction, and the front-rear direction is the footwear that has an upper and a sole. A plurality of grooves extending in the front-rear direction are formed in a line in the left-right direction on the back surface portion of the toe side of the sole, when the direction perpendicular to the left-right direction is defined as the left-right direction.

Further, the footwear according to the present invention is a footwear having an upper and a sole, wherein a low coefficient of static friction region is provided on a back surface portion on the toe side of the sole, and the coefficient of static friction of the low static friction coefficient region is equal to the coefficient of static friction of the low static friction coefficient region. It is characterized by a coefficient of static friction that is smaller than that of the back surface of the sole on the heel side.

Furthermore, the footwear according to the present invention is footwear having an upper and a sole,
A low coefficient of static friction region is provided on the back surface of the sole on the toe side, and the direction connecting the tip of the toe side of the footwear and the rear end of the heel side is the front-rear direction, and the direction perpendicular to the front-rear direction is the left-right direction. The present invention is characterized in that the coefficient of static friction with respect to the movement of the sole in the front-rear direction is smaller than the coefficient of static friction with respect to the movement of the sole in the left-right direction.

Further, the footwear according to the present invention is a footwear for playing a piano that has an upper and a sole, and when the footwear is worn and a pedal of the piano is operated with the foot, the back surface portion of the sole that comes into contact with the pedal is a part of the footwear. Piano playing footwear characterized by having a shape that is convexly curved downward when viewed from the toe side.

It is preferable that the above-described footwear according to the present invention includes an insole on the sole, and a recess shaped to cover the side surface of the heel is formed in a portion of the insole that contacts the heel.

According to the footwear of the present invention, it is possible to stably operate the piano pedals, especially when playing the piano. As a result, the burden on the feet when operating the pedals can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an embodiment of the present invention, in which (a) is a side view, (b) is a front view, (c) is a rear view, and (d) is a bottom view. It is a figure showing the positional relationship between the piano pedal and the player's foot during pedaling, (a) is the state in which the pedal is depressed, (b) is the state before the pedal is depressed, and (c) is the state in (a). This shows the state where the toe is raised and the pedal is released. FIG. 3 is an explanatory diagram showing a method of measuring a static friction coefficient. It is a table showing the measurement results of the coefficient of static friction. It is an explanatory view showing a measurement result of myoelectric potential at the time of pedal operation. It is an explanatory view showing the measurement result of the acceleration of the foot at the time of pedal operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of footwear according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 illustrates the relationship between the player's footwear and the pedals provided at the bottom of the piano when the player plays the piano. In addition, in FIG. 2, only the feet of the piano player are shown, and the depiction of the entire body is omitted. Figure 2 (a) shows the state in which the pedal is depressed, Figure 2 (b) shows the state before the pedal is depressed, and Figure 2 (c) shows the state in which the toe is raised and the pedal is returned from the state in (a). . Note that the vertical broken line in the figure is an auxiliary line provided to indicate the position where the heel is in contact with the floor.

The piano player adjusts the height of the chair and sits on the chair so that the angle of the fingers and body posture are correct relative to the piano keys, and the big toe of the right foot and the The player plays the piano by placing the footwear 21 on the pedal 22 so that the inner part of the foot slightly from the base of the index finger touches about one-third to one-fourth of the pedal 22.

When the toe is raised and the pedal is returned from the state shown in Fig. 2(a), the sole of the footwear 21 slips against the pedal 22, and as shown in Fig. 2(b), it is more stable if the heel position does not change. It is ideal because the pedals can be operated and there is less strain on the feet of the piano player. However, if the sole of the footwear 21 does not easily slip on the pedal 22, as shown in FIG. A phenomenon in which the footwear 21 is pushed backward by the pedal (hereinafter referred to as heel back) may occur. Additionally, if the heel position is not stabilized due to heel back, ``shake'', where the foot wobbles from side to side, is likely to occur.

When heelback occurs in this way, pedal operation is hindered and stable pedal operation is not possible. Therefore, the piano player has to adjust the position of his feet each time, which increases the burden on his feet. In addition, there is a risk that the player's attention will be focused on the operation of his feet while playing, and he will not be able to concentrate on the movement of his fingers.

When we conducted interviews with many piano players, we found that the piano players themselves were not particularly aware that heelback was occurring. In other words, although he was not concerned about heel back, he unconsciously moved his heel position when heel back occurred. The present inventor was the first to pay attention to the heel-back phenomenon, and by improving the sole of the footwear, he was able to invent footwear that allows stable pedaling without putting unnecessary strain on the foot.

[Footwear according to an embodiment of the present invention]
The footwear 1 suitable for playing the piano according to the present invention is designed to enable more stable pedal operation than conventional ones, thereby reducing the burden on the feet during such piano playing. be.

FIG. 1 shows the footwear of the present invention, and shows a slipper suitable for indoor use as an example. In the footwear 1 of the present invention, the footwear main body includes an upper 2 (also referred to as an upper or upper leather) that covers the instep of the foot, and a sole 3. In the case of slippers, the upper 2 generally covers only the instep part on the toe side, but may also cover the heel side. Further, an insole 4 is provided on the sole 3. In this insole 4, the part that the sole of the foot touches is shown by a broken line in Fig. 1(a), but it is, for example, a three-dimensional insole called a footbed that is made to match the shape and unevenness of the sole of the foot. This is desirable. In particular, the heel side preferably has a shape that covers the sides of the heel. By using the insole 4 as a footbed in this way, the heel is held in the recess, so there is no worry that the heel will slip down or come off during pedal operation. Further, in this embodiment, a heel 5 is provided on the heel side of the sole 3. Note that the insole 4 and the heel 5 may each be separate from the sole 3, or may be integrally molded together with the sole 3 by injection molding or the like so that there is no border.

As shown in FIGS. 1(b) and 1(d), a plurality of grooves 6 are formed on the toe side of the back surface of the sole 3 in an area that comes into contact with the pedal when operating the piano pedal. The groove 6 is formed so as to extend in the front-rear direction when viewed from the player (that is, the direction connecting the tip on the toe side and the rear end on the heel side). The broken line in FIG. 1(d) is the center line connecting the tip of the sole on the toe side to the rear end of the heel side, and each groove 6 can be formed in line so as to be substantially parallel to this center line. preferable. If the shoe size is 23.5 cm, the longest groove in the center should be approximately 10 to 11 cm long. Note that in FIG. 1D, a dividing groove 7 is formed to surround a plurality of grooves 6 in order to separate the area where the grooves 6 are formed from the other areas. The distance from the dividing groove 7 to the end (side surface) of the sole 3 on the toe side and side surface side is preferably about 5 mm to 10 mm. Note that this partitioning groove 7 is not necessarily necessary and may be omitted.

As described above, in the present invention, by forming the grooves 6 so as to extend in the front-rear direction when viewed from the player, effects not found in the prior art can be achieved. That is, in the present invention, the region where the grooves 6 are formed (that is, the region surrounded by the partitioning grooves 7 in this embodiment) becomes the low static friction coefficient region 8. In this low static friction coefficient region 8, the contact area with the pedal is reduced by providing a plurality of grooves 6 in the sole 3, and the static friction coefficient (that is, frictional resistance) in the front-rear direction is reduced. As a result, the low static friction coefficient region 8 easily slides on the pedal in the front and back direction. The static friction coefficient of the low static friction coefficient region 8 is smaller than the static friction coefficient of the heel side sole (or heel) without grooves. As a result, when the pedal is operated, the low friction coefficient region 8 slides smoothly on the pedal, thereby stabilizing the contact position between the sole (or heel) on the heel side and the floor. By stabilizing the ground contact position of the sole (or heel) on the heel side, the performer can perform ideal pedal operations, and as a result, the pedals can be operated with much less energy than before, which increases the impact on the foot muscles. can reduce the burden of Incidentally, regardless of whether the floor material is wooden flooring, a carpet, or a carpet, the footwear of the present invention can be expected to have the effect of stabilizing the grounding position of the sole (or heel) on the heel side.

Further, in the present embodiment, the static friction coefficient region 8 has a smaller static friction coefficient with respect to the movement of the sole 3 in the front-rear direction than the static friction coefficient with respect to the movement of the sole 3 in the left-right direction. If the coefficient of static friction in the left-right direction is the same as or smaller than the coefficient of static friction in the front-rear direction, the sole 3 will also slip in the left-right direction, causing the foot to wobble left and right (a phenomenon in which it wobbles left and right). ), if this vibration is large, you may miss the pedal. In this embodiment, since each groove 4 extends in the front-rear direction, an edge effect is exerted by the convex portion between each groove in the left-right direction, increasing frictional resistance (static friction coefficient), and the sole 3 moves from side to side. It is difficult to slip in any direction.

Furthermore, in this embodiment, the appearance shape of the sole 3 is also devised. That is, as shown in FIG. 1(b), when the footwear 1 is viewed from the front (toe side), the region where the static friction coefficient region 8 is formed (i.e., the region in contact with the pedal) is convex downward. It is preferable to have a curved shape. Due to this shape, when the user starts to press the pedal or when the user takes his/her foot off the pedal, the contact area between the sole 3 and the pedal is small, and the frictional resistance in the front and rear direction can be further reduced. In addition, when the pedal is strongly depressed or when walking, it is desirable that the deformation becomes flat due to the load. By deforming into a flat shape, as the ground contact area increases as the pedal is depressed, the edge effect of the grooves makes it difficult for the foot to wobble in the left-right direction. Note that the back surface of the sole 3 on the heel side (in this embodiment, the back surface of the heel 5), that is, the surface in contact with the floor, is a flat area in consideration of stability when walking, as shown in FIG. 1(c). It is preferable to have.

Next, the dimensions of the grooves 6 and the distance between the grooves 6 (the width of the plane portion between the grooves) will be explained. By increasing the width of the grooves 6 or increasing the number of grooves 6, the frictional resistance (static friction coefficient) against movement in the front-rear direction can be reduced. On the other hand, the distance between the grooves 6 should be set to a length that allows the edge effect to be expected ( or the thickness of the wall between the grooves). As a result of studies conducted by the inventor, the width of the grooves 6 is preferably 0.5 mm to 3.0 mm, and the distance between the grooves 6 (width of the plane portion between the grooves) is 1 mm to 3.0 mm. It was found that 0 mm is preferable. Note that the distance between the grooves 6, where A is the total width of the plurality of grooves 6 and B is the total distance between the grooves, the value of A/(A+B) must be in the range of 0.2 to 0.5. is preferred. Note that the shape of the groove 6 is preferably a V-shaped groove or a U-shaped groove, and the depth does not need to be very deep, and may be about 0.5 mm to 3 mm.

Next, the material of the sole 3 will be explained. Examples of materials that can be used as the sole 3 include natural rubber, synthetic rubber (such as isoprene rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, etc.), synthetic resins (polyurethane, EVA (ethylene vinyl acetate)). Note that the synthetic rubber or synthetic resin may be a foam.

[Footwear according to other embodiments of the present invention]
In the above embodiment shown in FIG. 1, the groove 6 is a linear groove, but if the frictional resistance against movement in the front and back direction does not become extremely large, it may have a wavy shape or a zigzag shape meandering at a gentle angle. It's okay to have one.
Further, in the embodiment shown in FIG. 1, the concave groove 6 is provided on the back surface of the sole, but it may be convexly raised. As a result, grooves are formed between the convex ridges arranged in a line, and a low coefficient of static friction region is formed similarly to the above embodiment shown in FIG.
In the above embodiment shown in FIG. 1, the low static friction coefficient region 8 is formed by the grooves 6, but instead of the grooves, the surface of the low static friction coefficient region 8 is roughened (a state in which small protrusions are widely distributed). ) to reduce the contact area with the pedal, and the static friction coefficient of the low static friction coefficient region 8 may be made smaller than the static friction coefficient of the back surface portion on the heel side of the sole.

[Measurement of static friction coefficient]
Next, the method and results of measuring the coefficient of static friction will be explained. First, Sample 1 and Sample 2 were prepared by cutting into a size of 2.5 cm x 2.5 cm from a foamed EVA plate having grooves 1 mm wide and 0.6 mm deep at 2 mm intervals on the surface. In addition, Sample 3 was prepared by cutting a foamed EVA plate with no grooves into a size of 2.5 cm x 2.5 cm. Similarly, Samples 4 and 5 were prepared, which were cut into a size of 2.5 cm x 2.5 cm from a synthetic rubber plate having grooves 1 mm wide and 0.6 mm deep at 2 mm intervals on the surface. In addition, Sample 6 was prepared by cutting a synthetic rubber plate with no grooves into a size of 2.5 cm x 2.5 cm. Synthetic rubber is the material used for the soles of men's shoes, and is made mainly from synthetic rubbers and synthetic resins such as styrene/butadiene rubber, nitrile/butadiene rubber, and additives such as softeners and colorants. It is common to mix and knead the chemicals and heat and pressurize the mixture.

Next, the static friction coefficient μ of Samples 1 to 6 was measured as shown in FIG. That is, as shown in FIG. 3(a), one side of the metal plate 31 is gradually raised from the state where the sample 32 is placed at the placement point P on the metal plate 31, and as shown in FIG. 3(b). As shown, the static friction coefficient (μ=A/B) can be calculated by measuring the height A and distance B when the sample 32 slides. In this measurement, an aluminum plate was used as the metal plate 31, and a load of 48 g was applied to the sample 32. Further, Samples 1 and 4 were set so that the grooves of Samples 1 and 4 were parallel to the sliding direction. Further, Samples 2 and 5 were set so that the grooves of Samples 2 and 5 were perpendicular to the sliding direction. Then, for each sample, the height A and distance B at which the sample slid down were measured five times (n=5), and the coefficient of static friction was calculated.

FIG. 4 shows the average value of the static friction coefficient of each sample calculated by measuring five times. As shown in this result, the static friction coefficient of Sample 1 or 4, which corresponds to the low static friction coefficient region 8, is smaller than that of Sample 3 or Sample 6, which corresponds to the back surface portion on the heel side of the sole 3. I understand that. In addition, the static friction coefficient for movement in the front-rear direction (specimen 1 or 4 applies) is smaller than the static friction coefficient for movement in the left-right direction (sample 2 or sample 5 applies) in the low static friction coefficient region 8. I understand.

(subject)
A test subject (female, 22 years old) was asked to wear footwear of Examples and Comparative Examples, which will be described later, and a comparative study was conducted to see what difference would occur in pedal operation.

(footwear)
As an example, slippers with a sole made of foamed EVA and a size of 23.5 cm (see FIG. 1 for the shape) were prepared. In addition, 22 grooves each having a width of 1 mm and a depth of 0.6 mm were formed on the toe side of the back surface of the sole, with a distance between the grooves (the width of the flat part) of 2 mm. Note that a dividing groove with a width of 1 mm and a depth of 0.6 mm was also provided, and the distance from the edge (side surface) of the sole to the dividing groove was approximately 5 mm. The length of the groove was 10 cm at the longest groove in the center. In addition, as a comparative example, ordinary slippers with a size of 23.5 cm without grooves formed on the back surface of the sole were prepared.

(attempt)
One trial consisted of fully depressing the pedal with the right foot three times and then half depressing it three times, and this was repeated four times. The speed of pedal depression was 80 times per minute, and a metronome was used to maintain a constant speed.

(Myoelectric potential measurement)
For myoelectric potential measurement, a Nihon Kohden telemetry system (WEB-5000) was used. The muscles tested were the four muscles of the right leg: tibialis anterior, gastrocnemius (lateral head), soleus, and peroneus longus. The outputs of these muscle activities were digitized using an A/D converter manufactured by AD Instruments at a sampling rate of 1 kHz and imported into a personal computer (Acer Travelmate P453).

(Forefoot acceleration measurement)
An accelerometer was attached to the forefoot of the right foot to measure the side-to-side vibration of the foot during pedaling. To measure the acceleration of the forefoot, we prepared three Kyowa Dengyo acceleration sensors (AS-20GA) attached to both ends and the center of an aluminum stay with a width of 2.5 cm and a length of about 12 cm. It was attached to the front of the footwear (above each finger) using double-sided adhesive tape at the time of measurement. The acceleration sensor was calibrated through a Kyowa Dengyo signal conditioner (CDV-700A) so that 1 G of gravitational acceleration would be an output of 0.1 V, connected to the A/D converter, and imported into a personal computer. The acceleration sensor attached to the end of the stay was placed to detect acceleration in the vertical direction, and the sensor in the center was placed to detect acceleration in the left-right direction. The outputs from the acceleration sensors at both ends of the stay are equal when the forefoot moves up and down without any roll motion, but there is a difference when the forefoot moves up and down with a roll motion. This allowed us to examine the magnitude of the roll motion of the forefoot.

(result)
The results of the trial are shown in Figures 5 and 6.
FIG. 5 shows the measurement results of the myoelectric potential, and shows the waveform and average myoelectric potential value of all three stepping movements during the four trials. As a result, it can be seen that the average myoelectric potential of all four muscles, the tibialis anterior muscle, the gastrocnemius muscle (lateral head), the soleus muscle, and the peroneus longus muscle, is smaller in the example than in the comparative example, and the muscle load is smaller. Further, the variation (standard deviation) of the myoelectric potential of the peroneus longus muscle is also smaller in the example than in the comparative example. From this, it can be seen that the example has better stability in pedal operation during piano performance.
Figure 6 shows the measurement results of acceleration, and the waveform of the difference between the acceleration values on the left and right sides of the foot is smaller in the example than in the comparative example, and the left and right shaking of the foot during pedal operation is suppressed in the example. I can see that

Although the above embodiment describes an example in which the present invention is applied to slippers, the present invention is not limited to this, but can also be applied to shoes (including men's shoes, high heels, and children's shoes) and sandals that have an upper that covers the entire foot. It is possible. Note that by applying the present invention to the ergonomic shoes for piano performance of Patent Document 1, the burden on the player's feet is further reduced, and the player can concentrate on hand movements.

1 Footwear 2 Upper 3 Sole 4 Insole 5 Heel 6 Groove 7 Division groove 8 Low coefficient of static friction region 21 Footwear 22 Pedal

Claims (4)

Footwear having an upper and a sole,
A low coefficient of static friction area is provided on the back side of the sole on the toe side,
The coefficient of static friction in the low coefficient of static friction region is smaller than the coefficient of static friction of the back surface portion on the heel side of the sole, and
When the direction connecting the tip of the toe side and the rear end of the heel side of the footwear is the front-rear direction, and the direction perpendicular to the front-rear direction is the left-right direction, the coefficient of static friction with respect to the movement of the sole in the left-right direction Also, footwear characterized in that the coefficient of static friction with respect to the movement of the sole in the front-back direction is smaller . 2. The footwear according to claim 1 , wherein a plurality of grooves extending in the front-rear direction are formed in the low static friction coefficient region in a line in the left-right direction. 2. The footwear according to claim 1, wherein the back surface portion of the sole has a shape that is convexly curved downward when the footwear is viewed from the toe side. Footwear according to any one of claims 1 to 3 , characterized in that an insole is provided on the sole, and a recess shaped to cover a side surface of the heel is formed in a portion of the insole that contacts the heel.