Patent Publication Number: US-2020276004-A1

Title: Pelvic floor muscle supporting aid

Description:
FIELD 
     The present invention relates to a pelvic floor muscle supporting aid that is worn on the crotch and has an aiding function to support the pelvic floor muscles from under. 
     BACKGROUND 
     The pelvic floor muscles (a generic name for levator ani muscle (pelvic diaphragm), anococcygeal ligament, deep transverse muscle of the perineum, urethral sphincter, levator ani muscle, and the like, which are also called the pelvic floor muscle group) lie on the bottom of the pelvis and function mainly to support the internal organs, but their function may be weakened by childbirth, aging, and so on. The weakened function of the pelvic floor muscles may cause urinary incontinence, bad posture, motor decline, and so on, and may also lead to a pelvic organ prolapse which is the falling down of the pelvic organs from the normal positions. Therefore, exercises whose aim is to enable a person to learn how to contract the pelvic floor muscles have been recommended. Japanese Patent No. 5661405 discloses a girdle for causing such exercises to be done properly to enhance the effect. This girdle includes extendable belt-shaped structures whose action regions are inner side portions of leg parts of the girdle and which each include a front lifting structure extending from the action region toward a front body and a back lifting structure extending from the action region toward a back body, and they transmit their pulling forces to each other owing to their elasticity. In this girdle, hardly extendable structures that hardly undergo elastic deformation are also formed on the action regions in the leg parts and their vicinity. The elastic force acts on the action regions in the leg parts to contribute to the contraction of the pelvic floor muscles. 
     Further, Japanese Patent Application Laid-open No. 2016-94690 relates to a supporter whose crotch wear article in a substantially flat plate shape is put on the crotch and is pulled upward with traction strings. This supporter supports the pelvic floor muscles while lifting them up, thereby preventing the function of the pelvic floor muscles from weakening. Japanese Patent No. 5492339 discloses women&#39;s underwear intended particularly to curb or prevent a pelvic organ prolapse by combining a stretchable sheet and a low-stretchable sheet. 
     SUMMARY 
     A pelvic organ prolapse is a phenomenon that the pelvic organs fall down from the normal position as described above, and owing to the gravity, force that tries to open the vaginal opening and causes the pelvic organs to come out acts. Therefore, only by simply applying, to the female genitals, force in such a direction as to press the pelvic floor muscles upward, it is difficult to prevent the vaginal opening from being opened, and it is not possible, either, to expect a high effect of recovering the function of the pelvic floor muscles. In this respect, in Patent Documents 1 and 2, a portion in contact with the crotch part with which the vagina or the pudendum is in direct contact is pressed upward, whereby the pelvic floor muscles are only pressed upward, and the effects of recovering the function of the pelvic floor muscles and preventing the pelvic organ prolapse cannot be expected much. Patent Document 3 states that the effect of preventing the pelvic organ prolapse is obtained, but the function obtained therein is substantially the same as those obtained in Patent Documents 1 and 2, and only the force pressing the crotch part upward acts. Accordingly, it doesn&#39;t seem that high effects of recovering the function of the pelvic floor muscles and preventing the pelvic organ prolapse can be expected. 
     The present invention was made in consideration of the above-described circumstances, and has an object to provide a pelvic floor muscle supporting aid that can contribute to the functional recovery of the pelvic floor muscles by supporting the pelvic floor muscles, thereby capable of preventing urinary incontinence and the like, and in addition that has a high effect of preventing a pelvic organ prolapse. 
     To solve the above problem, the present invention includes: 
     an annular part which is provided so as to be situated at a position corresponding to an outer peripheral portion of a vaginal opening when the pelvic floor muscle supporting aid is worn; and 
     a pulling part which is coupled with the annular part and pulls the annular part in at least a front direction or a back direction of the vaginal opening to narrow an interval between left and right side portions of the annular part, the left and right side portions being situated on left and right of the vaginal opening. 
     Preferably, the pelvic floor muscle supporting aid further includes a middle pressing part which is between the left and right side portions of the annular part and is pulled by the pulling part. 
     Further, preferably, the pelvic floor muscle supporting aid is of an underpants type having a front body, a back body, and a crotch part, 
     the annular part is provided in a range including the crotch part, and 
     the pulling part has a front pulling part provided on a range in the front body and a back pulling part provided on a range in the back body. 
     Preferably, the front pulling part includes a plurality of front pulling parts which are formed to fan out from a front portion of the annular part toward an upper portion of the front body, and the back pulling part has one end connected to a vicinity of a middle portion of a back portion of the annular part and has the other end extending toward an upper portion of the back body. 
     In this case, preferably, the plurality of the front pulling parts are two front pulling parts which form a substantially V shape, and the single back pulling part is provided along a vicinity of a widthwise middle portion of the back body. 
     Preferably, at least part of the annular part bulges in a thickness direction. Further preferably, at least part of the middle pressing part bulges in a thickness direction. 
     Further, the front body and the back body each can be formed of a cloth that does not easily get frayed from a cut edge. 
     According to the present invention, the annular part provided so as to be situated at the position corresponding to the outer peripheral portion of the vaginal opening is pulled by the pulling part, so that the interval between the left and right side portions situated on the left and right of the vaginal opening is narrowed. Consequently, not only force pressing up the pelvic floor muscles from under is applied but also the vaginal opening is narrowed. Since the pelvic floor muscles are supported by the upward force, it is possible to curb the loosening and damage of the pelvic floor muscles, which is effective for preventing urinary incontinence and the like. Further, since the vagina is supported from under against a pressure applied thereto from above, it is possible to reduce the expansion of the vagina and also prevent the pelvic organs from easily slipping out. That is, according to the pelvic floor muscle supporting aid of the present invention, it is possible not only to prevent urinary incontinence and the like by supporting the pelvic floor muscles but also to prevent the pelvic organ prolapse. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1( a )  is a perspective view of a pelvic floor muscle supporting aid according to one embodiment of the present invention seen from the front. 
         FIG. 1( b )  is a perspective view thereof seen from the back. 
         FIG. 2  is a developed view of the pelvic floor muscle supporting aid in  FIG. 1 . 
         FIG. 3  is an explanatory view of the operation of the pelvic floor muscle supporting aid and is a plan view of its annular part. 
         FIG. 4  is an explanatory view of the structure of an annular part of a pelvic floor muscle supporting aid according to another embodiment of the present invention and is a plan view of the annular part. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will be hereinafter described in more detail based on embodiments illustrated in the drawings.  FIG. 1  to  FIG. 3  are views illustrating a pelvic floor muscle supporting aid  10  of this embodiment. As illustrated in these drawings, the pelvic floor muscle supporting aid  10  of this embodiment is of an underpants type and has a front body  11  situated at the front, a back body  12  situated at the back, and a crotch part  13  which is between the front body  11  and the back body  12  and is situated at a position corresponding to the crotch. Inside the crotch part  13 , a crotch cloth for making the range of the crotch part  13  double-layered is provided. Note that the meaning of the underpants type mentioned here includes all the types ordinarily used as underwear and correction wear, including not only shorts type with short leg parts but also a type with long leg parts, a sanitary underwear type, and a girdle type. Further, the front body  11 , the back body  12 , and the crotch part  13  imply positions at which they are situated in the worn state, and the meaning of the underpants type also includes a type in which these parts are formed of separate cloths and are integrated by sewing, a type in which the plurality of portions are formed of an integrated cloth, and a seamless type in which there is no seam between these portions. 
     The pelvic floor muscle supporting aid  10  has an annular part  20  and a pulling part  30 . The annular part  20  is provided mainly on an inner surface of the crotch part  13  and depending on its size, also includes ranges adjacent to the crotch part  13  in the front body  11  and the back body  12 . The annular part  20  is provided in the range mainly in the crotch part  13  so as to be situated at a position corresponding to the outer peripheral portion of the vaginal opening when the pelvic floor muscle supporting aid  10  is worn. The meaning of “the outer peripheral portion of the vaginal opening” includes not only a portion directly adjacent to the periphery of the vaginal opening but also the outer peripheral portion of the labia minora and the outer peripheral portion of the labia majora. In short, the annular part  20  only needs to be situated at a position where it surrounds the outer side of the vaginal opening and is capable of applying force in such a direction as to close the vaginal opening. 
     As illustrated in  FIG. 2  and  FIG. 3 , the annular part  20  is, for example, elliptical in a plan view, and is provided such that its major axis direction is perpendicular to the width direction of the crotch part  13 . The annular part  20  has left and side portions  21 ,  22  which are situated at positions that sandwich the vaginal opening and are between the vaginal opening and two leg openings  15 ,  15  in the worn state, and of substantially linear sides forming the left and right side portions  21 ,  22 , end portions  21   a ,  22   a  close to the front body  11  are connected by a front portion  23 , and end portions  21   b ,  22   b  close to the back body  12  is connected by a back portion  24 . 
     It should be noted that, though the side portions  21 ,  22 , the front portion  23 , and the back portion  24  of the annular part  20  are all integrated in this embodiment, there may be a gap at each boundary between the side portions  21 ,  22  and the front and back portions  23 ,  24 , or any of the side portions  21 ,  22 , the front portion  23 , and the back portion  24  may be discontinuous. Further, the side portions  21 ,  22  may be slightly curved. Further, the front portion  23  and the back portion  24  each may have a slightly curved shape as illustrated in the drawings, a substantially linear shape, a chevron shape with the vicinity of its middle protruding outward, or the like. 
     The pulling part  30  has a function of pulling the annular part  20  in at least a front direction or a back direction to narrow an interval between the left and right side portions  21 ,  22  of the annular part  20 . In this embodiment, the pulling part  30  has front pulling parts  31  provided on ranges in the front body  11  and a back pulling part  32  provided on a range in the back body  12 . 
     The number of the front pulling parts  31  is two in this embodiment, and they form a substantially V shape with their one-side ends  31   a  connected to the front portion  23  of the annular part  20  and with their other ends  31   b  extending toward the upper portion of the front body  11  to be apart from each other. This is intended for preventing the front pulling parts  31  from pressing the urethral meatus and so on. 
     The back pulling part  32  has one end  32   a  coupled with the vicinity of a middle portion  24   a  of the back portion  24  and the other end  32   b  extending toward an upper portion of the back body  12 . That is, the single back pulling part  32  is provided along the vicinity of a middle portion of the back body  12  in terms of a width direction of the back body  12  (width direction of the pelvis). Note that, though the annular part  20  and the pulling part  30  (the front pulling parts  31  and the back pulling part  32 ) may be formed integrally of the same material as in this embodiment, they may be separately formed to be connected at the aforesaid portions. 
     As illustrated in  FIG. 3 , the front portion  23  of the annular part  20  is pulled in directions slightly fanning out to the left and right (the arrow A direction and the arrow B direction) by the two front pulling parts  31  forming the substantially V shape. Consequently, not only the vicinity of a middle portion of the front portion  23  but also the whole range of the front portion  23  is pulled in the aforesaid direction (the arrow C direction). On the other hand, as for the back portion  24 , since the single back pulling part  32  is connected to the vicinity of its middle portion  24   a , mainly the vicinity of the middle portion  24   a  is pulled toward the upper portion of the back body  12  (in the arrow D direction). When the vicinity of the middle portion  24   a  is pulled, the end portions  21   b ,  22   b  of the side portions  21 ,  22  situated at both ends of the back portion  24  are displaced in such directions as to narrow the interval therebetween (the arrow E direction and the arrow F direction). Consequently, the entire left and right side portions  21 ,  22  are displaced in such directions as to narrow the interval therebetween as indicated by the imaginary lines in  FIG. 3 . That is, the annular part  20  deforms such that its inner opening  20   a  becomes longer and narrower. When the side portions  21 ,  22  are thus displaced so as to narrow the interval therebetween, force to narrow the vaginal opening of the female genitals situated on an inner side of the side portions  21 ,  22  acts. 
     In this embodiment, the pelvic floor muscle supporting aid  10  is of the underpants type, and in a waist part  14  in the upper portions of the front body  11  and the back body  12 , rubber is disposed to make the waist part  14  fit around the waist of a wearer. Instead of disposing the rubber, densely disposing elastic yarns on the waist part  14 , coating the waist part  14  with synthetic resin, or the like can make only the waist part  14  higher in stretchability than the other portions of the front body  11  and the back body  12 . It is also possible to fit the waist part  14  around the waist by separating the waist part  14  into segments and joining the segments with buttons, hooks, or the like. Further, if the front body  11  and the back body  12  themselves are at least partly formed of elastic yarns or coated with synthetic resin to have certain stretchability and fit the wearer owing to the stretchability, the rubber or the like need not be provided in the waist part  14 . The front pulling parts  31  have the other ends  31   b  extending toward the upper portion of the front body  11  as described above. Preferably, the other ends  31   b  are connected to the waist part  14 . Similarly, the other end  32   b  of the back pulling part  32  extends to the upper portion of the back body  12 , and is preferably connected to the waist part  14 . Since the waist part  14  is held around the waist when the pelvic floor muscle supporting aid  10  is worn, tensile force acts on the front pulling parts  31  and the back pulling part  32  in the upward direction (direction from the crotch part  13  toward the waist part  14 ). As a result, the front portion  23  and the back portion  24  of the annular part  20  which are connected to the ends  31   a  of the front pulling parts  31  and the end  32   a  of the back pulling part  32  respectively are pulled, so that the inner opening  20   a  of the annular part  20  deforms to become longer and narrower as described above. 
     Here, since the pelvic floor muscle supporting aid  10  of this embodiment is of the underpants type, the front body  11 , the back body  12 , and the crotch part  13  are formed of a material used for ordinary underwear, correction wear, and the like, typically a material having predetermined stretchability. However, in the front body  11 , the back body  12 , and the crotch part  13 , on their portions corresponding to the aforesaid annular part  20  and pulling part  30 , the force which starts from the waist part  14  to pull them upward is applied at the time of the wearing. Therefore, for example, the portions corresponding to the annular part  20  and the pulling part  30  can be formed to be lower in stretchability along the planar direction (pulling direction) than the other portions, or the portions corresponding to the annular part  20  and the pulling part  30  can be formed to be high in elastic restoring force along the planar direction (pulling direction). Specific examples of adoptable means for the above include: coating the portions corresponding to the annular part  20  and the pulling part  30  with resin to make these portions low in stretchability; forming only these portions of a different material relatively low in stretchability or a different material high in elastic restoring force and joining these portions with the other portions by sewing or by overlapping these portions on parts of adjacent portions and pasting them together by fusion or the like; and stacking a different material low in stretchability or a different material high in elastic restoring force on these portions and joining them by sewing, fusion, or the like. In the case where the material different from that of the front body  11 , the back body  12 , and the crotch part  13  is joined by sewing or the like, this material may be any of woven fabric, paper, synthetic resin, and the like, but is preferably a soft material that gives less discomfort even when in contact with the female genitals and skin. 
     Further, the annular part  20  preferably has a three-dimensional shape with at least part thereof, preferably the side portions  21 ,  22 , bulging in the thickness direction. With this shape, the annular part  20  easily abuts on the outer peripheral portion of the vaginal opening, so that the force of biasing the vaginal opening in the closing direction by the annular part  20  easily acts. The annular part  20  may bulge in an outward direction, but preferably bulges inward, that is, in such a direction as to come into contact with the female genitals. A means for thus bulging the annular part  20  can be, for example, to stack a different material relatively lower in stretchability than the other portions, or the like on the portion corresponding to the annular part  20  as described above. The different material may be any of woven fabric, paper, synthetic resin, and so on and its kind is not limited as long as it is a soft material similarly to the above. Further, the material itself of the portion forming the annular part  20  disposed mainly on the crotch part  13  can be worked into a three-dimensional bulging shape. Note that, in the case where the annular part  20  at least partly bulges, its bulging height is not limited, but is preferably within a range of about 0.5 mm to about 20 mm and more preferably within a range of 1 mm to 5 mm in order to give less feeling of something foreign to the wearer, though different depending on the flexibility of the material and also depending on the bulging method, that is, depending on whether to bulge the material itself of the crotch part  13  or to stack the other material. 
     The operation of the pelvic floor muscle supporting aid  10  of this embodiment will be described. Since the pelvic floor muscle supporting aid  10  of this embodiment is of the underpants type, the wearer wears it by putting the legs into the leg openings  15 ,  15  in the same manner as he/she wears ordinary underpants. At this time, the pelvic floor muscle supporting aid  10  of this embodiment may be worn as innermost wear which directly comes into contact with the skin, or after ordinary underwear is worn, may be worn thereon. In either case, when the pelvic floor muscle supporting aid  10  of this embodiment is worn, the side portions  21 ,  22  of the annular part  20  are situated on the outer sides of the vaginal opening of the wearer, and at the same time, the front pulling parts  31  and the back pulling part  32  are pulled toward the waist part  14 . Consequently, the front portion  23  and the back portion  24  of the annular part  20  are pulled in opposite directions (the arrow C direction and the arrow D direction in  FIG. 3 ). As a result, the force to cause the annular part  20  to press the outer peripheral portion of the vaginal opening upward first acts to support the pelvic floor muscles. Consequently, it is possible to resist the pressure applied to the vagina from above to prevent the expansion of the vagina caused by the pressure. 
     Further, the back pulling part  32  is connected only to the middle portion  24   a  of the back portion  24 . Accordingly, when the front portion  23  and the back portion  24  of the annular part  20  are pulled in the opposite directions (the arrow C direction and the arrow D direction in  FIG. 3 ), the two side portions  21 ,  22  sandwiching the inner opening  20   a  of the annular part  20  try to be displaced in the directions in which they approach each other (the arrow E direction and the arrow F direction in  FIG. 3 ). As a result, the forces act in such directions as to close the wearer&#39;s vaginal opening, which is corresponding to the side portions  21 ,  22 , from the outer sides of the vaginal opening. 
     In short, according to this embodiment, owing to the annular part  20 , the force to press the outer peripheral portion of the vaginal opening of the wearer upward to support the pelvic floor muscles and the forces in such directions as to close the vaginal opening act simultaneously. The forces to close the vaginal opening act to retain the pelvic organs which have not slipped out from the vaginal opening, in the vagina by pressing. Therefore, the pelvic floor muscle supporting aid  10  of this embodiment operates to support the pelvic floor muscles to return them into the normal positions and at the same time is expected to have a high effect of preventing the pelvic organ prolapse. Further, since pressing the vaginal opening upward while closing it, the pelvic floor muscle supporting aid  10  can provide an effect similar to that of pelvic floor muscle exercise, further can contribute to an improvement in the exercise effect of the pelvic floor muscle exercise, and has high effects of preventing and curing urine leakage, uncontrolled urination, and the like. Further, since the back portion  24  of the annular part  20  is situated at the position corresponding to the perineal region, it is also effective for preventing and curing lymphedema and varix occurring in the perineal region. Further, since the crotch wear article in the substantially flat plate shape as described in the aforesaid Patent Document 2 is not used, thigh sore which may be caused by such a crotch wear article as a foreign object does not occur. 
       FIG. 4  is a plan view of the structure of an annular part  20  adopted in a pelvic floor muscle supporting aid  10  according to another embodiment of the present invention. In this embodiment, a middle pressing part  25  is provided as indicated by the imaginary line. The middle pressing part  25  is stacked on at least one side out of a front surface and a rear surface of the annular part  20  so as to be situated between side portions  21 ,  22  of the annular part  20  and is formed of a cloth or the like having a substantially elliptical outer periphery. The middle pressing part  25  only needs to be provided between the side portions  21 ,  22  of the annular part  20 , and may have a narrower width than an interval between the side portions  21 ,  22 , may be joined only to the vicinity of a front portion  23  and the vicinity of a back portion  24 , and may have such a size as to have an interval from the side portions  21 ,  22 . However, the wider its width, the softer its abutting feeling on the female genitals, which is more preferable. The middle pressing part  25  is formed of, for example, a material relatively lower in stretchability than the other portions of a front body  11  and a back body  12  similarly to the other portions (side portions  21 ,  22  and so on) of the annular part  20 . 
     Therefore, in a worn state, when the front portion  23  and the back portion  24  of the annular part  20  are pulled in opposite directions (the arrow C direction and the arrow D direction in  FIG. 3 ), the middle pressing part  25  tries to be displaced upward to press the female genitals. That is, since the middle pressing part  25  is disposed in the vicinity of the middle of the annular part  20 , force acts in a direction such that it comes into contact with the vaginal opening or in a direction such that it presses the vaginal opening. This force together with the side portions  21 ,  22  acts as force to press the pelvic floor muscles upward, and further acts as force pressing up the pelvic organs which have fallen down to the vicinity of the vaginal opening or pressing the pelvic organs which have slipped out from the vaginal opening, in such a direction as to push the pelvic organs inside. Therefore, according to this embodiment, not only the pelvic floor muscles are supported and in addition, the side portions  21 ,  22  of the annular part  20  try to close the vaginal opening, but also the force to press the fallen pelvic organs can act more strongly owing to the middle pressing part  25 . 
     Preferably, the middle pressing part  25  has a size such that its front portion and back portion are in contact with front pulling parts  31 ,  31  and a back pulling part  32  and it partly overlaps with the front pulling parts  31 ,  31  and the back pulling part  32 . This makes the pulling forces of the front pulling parts  31 ,  31  and the back pulling part  32  directly act on the middle pressing part  25 , making it possible to surely pull the middle pressing part  25 . Further, at least part of the middle pressing part  25  preferably bulges. In this case, preferably at least one of its inner surface and outer surface, more preferably at least its inner surface, bulges to protrude toward the vaginal opening. This can more increase the force pressing the pelvic organs. A method to form this bulging portion may be any, and it is possible to form the bulging portion by stacking a flexible material in a plate shape, a semicircular shape, or the like formed of cloth, synthetic resin, paper, or the like on the middle pressing part  25  to increase its thickness, or by forming a slit in the middle pressing part  25  in advance and detachably attach a member formed in a semicircular shape or the like to the middle pressing part  25 , with an end portion of the member inserted into the slit. Further, in the case where the annular part  20  formed mainly on the crotch part  13  is integrally formed with the crotch part  13  (or a crotch cloth provided inside) by resin coating or the like, a range surrounded by the annular part  20  can be the middle pressing part  25  as it is. In this case, stretchability or elastic restoring force is adjusted to differ among the annular part  20 , the middle pressing part  25 , the pulling part  30 , the front body  11 , the back body  12 , and so on such that, when the annular part  20  is pulled, the pulling force also acts on the middle pressing part  25  to press the female genitals while the side portions  21 ,  22  are displaced to approach each other. 
     In the above-described embodiments, the two front pulling parts  31  composing the pulling part  30  are arranged in the substantially V shape, but as long as they can pull the front portion  23  of the annular part  20 , their number, arrangement, shape, and so on are not limited. The back pulling part  32  only needs to be capable of pulling the vicinity of the middle portion  24   a  of the back portion  24  of the annular part  20 . Typically, the single back pulling part  32  is provided as in the above-described embodiments, but the number of the back pulling parts  32  may be two or more as long as they can pull the vicinity of the middle portion  24   a . For example, they can be disposed with their one-side ends connected to the vicinity of the middle portion  24   a , to fan out in a substantially V shape as they go toward an upper portion of the back body  12 . Further, the front pulling parts  31  and the back pulling part  32  may each have a bent portion or may be in a curved shape or the like instead of being linear. Further, the shape of the annular part  20  is not limited to the aforesaid shape as long as it can push the vaginal opening from left and right outer sides in the closing direction. 
     Further, in both of the above-described embodiments, the underpants-type pelvic floor muscle supporting aid  10  is shown, but instead of being of the underpants type including the front body  11  and the back body  12 , the pelvic floor muscle supporting aid  10  may be structured to include, besides the annular part  20  and the pulling part  30 , only a waist support member (not illustrated) supporting the pulling part  30  around the waist of a wearer. However, the aforesaid underpants type is easy to wear. 
     Further, as the material forming the front body  11  and the back body  12  of the pelvic floor muscle supporting aid  10 , also usable is a cloth that does not get frayed from its cut edge, at whichever position it is cut. In this case, it is possible to provide the pelvic floor muscle supporting aid  10  in a state where the upper portions of the front body  11  and the back body  12  are at a high position, for example, around the navel so that the wearer can cut it at his/her desired position when he/she uses it. Similarly, it is possible to form, on leg openings  15  sides, leg insertion portions extending to the vicinity of the knees or the vicinity of the ankles so that the wearer can cut them at his/her desired position for length adjustment. Further, the pelvic floor muscle supporting aid  10  may be formed and provided as a bodysuit type so as to allow the wearer to cut it into his/her desired shape. By having an increased degree of freedom in shape and design, the pelvic floor muscle supporting aid  10  can suit the taste of the wearer to be more comfortable to wear. Further, cutoff lines (perforations) may be provided at, for example, several mm to several cm intervals in advance so that the wearer can cut it along the cutoff line at his/her desired position for length adjustment. Note that, as the cloth that does not easily get frayed, various conventionally known cloths are usable, and examples of the usable cloth include a knit structure of a non-elastic yarn and an elastic yarn running side by side, at least one of which is formed into closed stitches to prevent fraying from a cut edge as is disclosed in Japanese Patent Application Laid-open No. 2003-147618, an elastic cloth having a knit structure whose cut edge does not get frayed as is disclosed in Japanese Patent Application Laid-open No. 2009-215676, and one in which silicone resin is applied on a cloth formed of elastic yarns to prevent the fraying at its cut edge as is disclosed in Japanese Utility Model Registration No. 3123137.