Thumb post / thumb spica type TPU thumb immobilization brace

Abstract

To provide a thumb fixing device made of TPU material that fixes the joint around the thumb, leaving mobility while reducing pain, and can be used for wet work. Solution: A hard TPU material is used, which is non-absorbent and provides a certain degree of fixation even at a thickness of 1.2-1.5mm. The TPU is designed using a draping method to fit the hand. To reduce pain when worn during daily activities, the device is not completely fixed, but rather designed with three parts to allow some mobility. It uses a mixed male-female hook-and-loop fastener that can be easily replaced by passing it through a slit and folding it to fix it when it gets wet, such as when doing water work. Two types of designs are available: a thumb post type that allows freedom of movement at the wrist, and a thumb spica type that also fixes the wrist.

Description

[Technical Field]

[0001] This invention involves the creation of a thumb post (an orthosis that fixes the area from the IP joint of the thumb to the distal part of the wrist) and thumb spica (an orthosis that fixes the area from the IP joint of the thumb to the proximal part of the wrist) type orthosis that fixes the joints around the thumb (MP joint of the thumb and CM joint of the thumb) made of three parts using a harder TPU material, which are not completely fixed but leave some mobility to allow for a slight amount of play, causing less pain when worn and allowing it to be used even when doing wet work. [Background technology]

[0002] For conditions around the hand such as De Quervain's disease (wrist tenosynovitis), thumb CM joint arthritis, and carpal tunnel syndrome, conservative treatment often involves the use of plaster braces, plastic braces, or fiber braces such as neoprene. However, plaster braces and plastic braces often have too much fixation force to be used in daily life, or can only be worn for short periods of time due to pain when worn. Furthermore, fiber braces such as neoprene often cannot be used for wet work and deteriorate in a short period of time.

[0003] Fiber-made orthoses for thumb CMC joint arthritis have been reported in JP 2016-533828, JP 2020-69362, and JP 2021-7527, and fiber-made orthoses for wrist joints have been reported in JP 2013-22344, JP 2013-104139, and JP 2025-14616, but they often had inconveniences such as being unable to be used for wet work and having weak fixation strength. Silicone and plastic orthoses for thumb CMC joint arthritis have been reported in JP 2001-218781 and JP 2018-7773, and wrist orthoses have been reported in JP 1998-14960, but they often had weak fixation strength and were ineffective, or could not be worn for long periods of time due to pain when worn. Recently, a patent publication No. 2021-508266 has been reported that combines a textile brace with a hard material such as plastic, but it still could not be used for wet work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-533828 [Patent Document 2] Japanese Patent Publication No. 2020-69362 [Patent Document 3] Patent Publication No. 2021-7527 [Patent Document 4] Japanese Patent Application Laid-Open No. 2013-22344 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-104139 [Patent Document 6] Japanese Patent Application Laid-Open No. 2025-14616 [Patent Document 7] Japanese Patent Application Laid-Open No. 2001-218781 [Patent Document 8] Japanese Patent Application Laid-Open No. 2018-7773 [Patent Document 9] Japanese Patent Application Laid-Open No. 1998-14960 [Patent Document 10] Patent Publication No. 2021-508266 Summary of the Invention [Problem to be solved by the invention]

[0005] Rigid braces, such as plaster braces and plastic thumb post braces (braces that fix the thumb from the IP joint to the distal part of the wrist), are rigid and provide strong fixation, but when used in daily activities, they excessively restrict necessary movements, forcing people to remove the brace every time they need to perform a task, or forcing people to wear them while working can cause many inconveniences, such as the brace digging into the skin, causing scratches from rubbing inside, or putting strain on the surrounding joints and causing pain in other areas. Rigid braces also tend to become sweaty and need to be cleaned when soiled with sweat, but bands are often attached to the brace, which often gets wet and causes discomfort when reattaching. On the other hand, soft braces made of fiber materials are soft, so they have weaker fixation and often have a larger fixation range. Most products are thumb spica type (orthoses that fixate from the IP joint of the thumb to the proximal wrist), and many combine metal or plastic splints to increase fixation strength. While the fit is good, the large fixation range makes it inconvenient when using the toilet or performing daily activities, and patients often end up removing the orthosis. It also cannot be used for wet work. There are also issues with the fibers being damaged and deteriorating quickly. The ideal orthosis would be one that is neither too strong nor too weak, that causes little pain when worn, causes little inconvenience when performing daily activities, can be used for wet work, and does not deteriorate easily. [Means for solving the problem]

[0006] (1) It is made of a hard TPU material that is non-absorbent and provides a certain degree of fixation even at a thickness of 1.2 to 1.5 mm. (2) TPU is a material that can bend but does not stretch, so it is designed using the draping method to fit the hand. (3) In order to reduce pain when wearing the device during daily activities, it is not completely fixed, but is designed as a three-part device that allows some mobility. (4) The hook-and-loop fastener is designed to be foldable and fastened through a slit, so that it can be easily replaced when it gets wet from doing water work. (5) Two types of designs were designed: a thumb post type (a device that fixes the area from the IP joint of the thumb to the distal part of the wrist) that allows the wrist to be free, and a thumb spica type (a device that fixes the area from the IP joint of the thumb to the proximal part of the wrist) that also fixes the wrist. This invention solves the problem by using the material (1) and designing it with the features (2) to (5). [Effects of the Invention]

[0007] The use of this invented thumb post / thumb spica type TPU thumb immobilization brace is expected to improve symptoms such as pain and numbness caused by hand disorders such as De Quervain's disease (stenosing tenosynovitis), thumb CM joint arthritis, and carpal tunnel syndrome. Furthermore, due to the characteristics of the material and design, the following effects (1) to (5) can be expected. (1) The use of TPU, a non-absorbent material, makes it possible to use it for wet work, and by using TPU with a relatively hard hardness of 72D, it is possible to maintain a good balance between flexibility and fixation even when made thin, at 1.2 to 1.5 mm. (2) By introducing the draping method during the design stage, it is possible to fit the device to the complex shape of the hand, and by using flat parts, manufacturing costs can be significantly reduced. (3) When the thumb is completely immobilized using plaster cast material or hard plastic, the corners of the brace dig into the skin during daily activities, causing pain. This often leads to excessive force being exerted inside the brace, rubbing the skin and causing skin problems. Therefore, the brace was designed to allow a certain degree of movement. Specifically, the thumb part is designed to be loose, rather than tightly fitted to the thumb. The thumb part is intentionally fixed to the thenar and metacarpal parts at a single point, slightly proximal to the thumb MP joint. When the thumb IP joint is flexed, the unfixed parts move and sink, reducing pain during movement. In thumb post-type thumb immobilization braces, the thenar and hypothenar parts are fixed at only two separate points to minimize interference with movements of the thumb. In thumb spica-type thumb immobilization braces, the dorsal side of the thumb is completely immobilized at two points, while the palmar side of the thumb is fixed at only one point. By allowing rotational movement at the fixed part on the palm side of the thumb, we have made it possible to minimize the obstruction of movement of joints other than the thumb MP joint, thumb CM joint, and wrist joint, which we want to fix. (4) In general braces, one side of the hook-and-loop fastener is often fixed, so it cannot be replaced even if it gets wet while doing water work, and it is necessary to simply wipe it off and put it back on while it is still wet, or to take the trouble of drying it with a hair dryer.By simply passing the hook-and-loop fastener (male-female mixed type) through the slit and folding it back, it becomes possible to easily replace the hook-and-loop fastener even if it gets wet. (5) Thumb post-type thumb immobilization braces (braces that immobilize the thumb from the IP joint to the distal part of the wrist) that allow the wrist joint to be free are useful for conservative treatment of CMC joint arthritis of the thumb, and thumb spica-type thumb immobilization braces (braces that immobilize the thumb from the IP joint to the proximal part of the wrist) that also restrict the movement of the wrist are effective for De Quervain's disease (wrist tenosynovitis) and carpal tunnel syndrome. By producing two types, you can choose the brace that best suits your symptoms. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an overall view of a thumb post type thumb immobilization brace and a thumb spica type thumb immobilization brace of the present invention. [Figure 2]FIG. 1 is an exploded view of a thumb post type thumb immobilization brace. [Figure 3] This is the assembled state of a thumb post type thumb immobilization brace. [Figure 4] This is the state of wearing a thumb post type thumb immobilization brace. [Figure 5] Actual movement limitations and ADL (mouse operation, writing, and chopstick use) when wearing a thumb post-type thumb brace. [Figure 6] FIG. 1 is an exploded view of a thumb spica-type thumb immobilization brace. [Figure 7] This is the assembled state of a thumb spica type thumb fixation brace. [Figure 8] This is the state of wearing a thumb spica type thumb fixation brace. [Figure 9] These are actual movement limitations and ADL (mouse operation, writing, and chopstick use) when wearing a thumb spica-type thumb brace. [Figure 10] FIG. 10 is an explanatory diagram of the movable parts of a thumb post type thumb fixing brace and a thumb spica type thumb fixing brace. DETAILED DESCRIPTION OF THE INVENTION

[0009] Explain how to use the brace. Move the edge of the hook-and-loop fastener as far as it will go into the slit to expand the brace, then insert the thumb part onto the thumb to fit the brace. For thumb-post-type thumb immobilization braces, adjust the hook-and-loop fastener tension on the back of the hand. For thumb-spica-type thumb immobilization braces, adjust the hook-and-loop fastener tension on the ulnar side of the proximal wrist. The large size is made for men, with the medium size for women reduced by 90% and the small size for children reduced by 80%. If the brace does not fit, cut it with scissors or modify the design to customize it. Pain can be alleviated by cutting and attaching car door molding to the edge of the brace near the IP joint of the thumb, the distal edge of the hypothenar part for thumb-post-type thumb immobilization braces, and the proximal edge of the wrist for thumb-spica-type thumb immobilization braces. [Example]

[0010] An example will be described below with reference to the attached drawings. Each part was designed using 3D-CAD and printed using a 3D printer as a prototype. A thumb post-type brace for immobilizing the thumb (bracing from the thumb interphalangeal joint to the distal wrist) that allows the wrist to be free: (1) A cylindrical part (thumb part) extending from slightly proximal to the thumb interphalangeal joint. (2) A flat part (thenar part) designed as an extension of a bow tie shape into a band, covering the entire thenar joint from the thumb interphalangeal joint to the end of the lifeline (wrist joint) using a draping method. (3) A flat part (hypothenar part) designed to cover the thenar joint and follow the head and lifelines. Parts (1) to (3) were designed with a thickness of 1.2 mm. The three parts were printed using a 3D printer using TPU with a hardness of 72D. They were then molded into a three-dimensional shape and secured with rivets. The thenar and hypothenar parts were secured at two points: the end of the lifeline (wrist joint) and the intersection of the lifeline and head line. Two hook-and-loop fasteners were passed through the slits and fixed to the back of the hand. 3D printer output results showed a printing time of 120 minutes, running costs of 60 yen, and a weight of 14 g. The total weight with the hook-and-loop fastener and door molding attached was 19 g. Range of motion and ADL: (a) There was no restriction in the range of radial abduction of the thumb, but the range of ulnar adduction and opposition was limited. (b) There was no restriction in the range of palmar abduction of the thumb, and pinching was also possible, but the range of palmar adduction was slightly limited. (c) There was no restriction in the range of palmar flexion and dorsiflexion of the wrist. (d) The patient was able to use a mouse, pen, and chopsticks. Thumb spica type braces (breast braces that immobilize the area from the thumb interphalangeal joint to the proximal wrist joint) include: (1) a cylindrical part (thumb part) extending from slightly proximal to the thumb interphalangeal joint. (2) a flat part (metacarpal part) extending from the thumb interphalangeal joint to slightly distal to the CM joint (first metacarpal part), covering approximately half of the ball of the thumb, and designed like the letter J, molded using the draping method. *Partially fenestrated to prevent stuffiness. (3) a flat part (wrist part) extending from the distal forearm proximal to the wrist, covering half of the radius, with a semicircular hole in the center to relieve pressure from the CM joint to the radial styloid process, and extending from both ends in a 15 mm band shape at a 45-degree angle toward the metacarpal part. The three parts (1) to (3) were designed with a thickness of 1.2 mm. The three parts were printed using a 3D printer using TPU with a hardness of 72D. They were then 3D molded and secured with rivets. The metacarpal and wrist parts were secured at one location on the palmar side and two locations on the dorsal side. Two hook-and-loop fasteners were passed through the slits and secured to the distal forearm, proximal to the wrist. The 3D printer output resulted in a print time of 110 minutes, a running cost of 50 yen, and a weight of 12 g. The total weight with the hook-and-loop fasteners and door molding attached was 19 g. Range of motion and ADL: (a) There was no restriction in the range of motion for radial abduction of the thumb, but the range of motion for ulnar adduction and opposition was limited. (b) There was no restriction in the range of motion for volar abduction of the thumb, and pinching was possible, but the range of motion for volar adduction was slightly limited. (c) The range of motion for palmar flexion and dorsiflexion of the wrist was limited. (d) The subject was able to use a mouse, pen, and chopsticks. [Explanation of symbols]

[0011] 1 Little finger ball part (thumb post type) 2 Ball of the foot part (thumb post type) 3 Thumb parts (thumb post type) 4 Hook-and-loop fasteners (thumb post type) 5 Door molding (thumb post type) 6 Wrist joint parts (thumb spica type) 7 Metacarpal parts (thumb spica type) 8 Thumb parts (thumb spica type) 9. Hook and loop fastener (thumb spica type) 10 Door molding (thumb spica type)

Claims

1. This thumb immobilization brace is made by joining two flat parts and one cylindrical part made of TPU, which are molded using the draping method, with rivets to form a three-dimensional shape, and then fixing it to the back of the hand or wrist with hook-and-loop fasteners.

2. The thumb immobilization device described in claim 1 is designed so that the three parts are not completely fixed even when three-dimensionally molded, allowing for a slight amount of play when moving the thumb or wrist, thereby reducing pain when wearing the device.

3. The thumb immobilization brace described in claim 1 uses a type of hook-and-loop fastener (male-female mixed type) that does not directly fasten the hook-and-loop fastener to the flat part, but can be passed through a slit and folded back to secure it, and is designed so that the hook-and-loop fastener can be easily replaced if it gets wet due to water work, etc.

4. (1) A cylindrical part (thumb part) extending from slightly proximal to the thumb MP joint to slightly proximal to the thumb IP joint. (2) A flat part (ball of the thumb part) that covers the entire ball of the thumb from the MP joint to the end of the lifeline (wrist joint) and is molded using the draping method, with a design that extends part of the bow tie shape into a belt shape. (3) A flat part (pinky ball part) that covers the little finger ball and is designed along the head line and life line. The thumb immobilization orthosis according to claim 1 is a thumb post type (an orthosis that immobilizes the area from the IP joint of the thumb to the distal part of the wrist) that is composed of the three parts (1) to (3) above, is fixed at the back of the hand with two hook-and-loop fasteners, and leaves the wrist free.

5. (1) A cylindrical part (thumb part) extending from slightly proximal to the thumb MP joint to slightly proximal to the thumb IP joint. (2) A flat part (metacarpal part) measuring from the MP joint of the thumb to the CM joint slightly distal to it (first metacarpal part), covering about half of the ball of the thumb, and designed like the letter J, molded using the draping method. (3) A flat part (wrist joint part) in the distal part of the forearm proximal to the wrist joint, with a rectangular central part long enough to cover the radial half, with a semicircular hole drilled in order to decompress from the CM joint to the radial styloid process, and extending from both ends in a 15 mm band shape at a 45 degree angle toward the metacarpal part. The thumb immobilization orthosis according to claim 1 is a thumb spica type (an orthosis that immobilizes the area from the IP joint of the thumb to the proximal part of the wrist) that is composed of the three parts (1) to (3) above, is fixed with two hook-and-loop fasteners at the distal part of the forearm proximal to the wrist, and immobilizes the area from the thumb to the wrist.

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