ORTHOSIS FOR PLACEMENT ON A HUMAN HAND

Abstract

The invention relates to an orthosis (1) for wearing on a human hand (2) to restrict motion of at least the carpometacarpal joint (CMCj) of the thumb and preferably also of the metacarpophalangeal joint (MCPj) of the thumb (2-1), the orthosis (1) comprising a metacarpus section (3), which, when the orthosis (1) is worn on a hand, extends across the metacarpals of digits 2-5, and a thumb section (4), which section is curved or annular in shape and fits around the thumb (2-1), preferably around the proximal phalanx (6) of the thumb (2-1). The thumb section (4) is connected to the metacarpus section (3) via a thumb metacarpal section (7) that, when the orthosis (1) is worn on a hand (2), extends along and/or around the thumb metacarpal (8).

Claims

1. An orthosis for wearing on a human hand to restrict motion of at least a carpometacarpal joint of a thumb, the orthosis comprising a metacarpus section, which, when the orthosis is worn on a hand, extends across metacarpals of digits 2-5, and a thumb section, which section is curved or annular in shape and fits around the thumb, wherein the thumb section is connected to the metacarpus section via a thumb metacarpal section that, when the orthosis is worn on the hand, extends along and/or around a thumb metacarpal.

2. The orthosis according to claim 1, wherein the thumb metacarpal section is cantilevered to the metacarpus section.

3. The orthosis according to claim 1, wherein the thumb metacarpal section extends helically between the metacarpus section and the thumb section.

4. The orthosis according to claim 1, wherein, when the orthosis is worn on the hand, a reaction force on the thumb section is proportional to movement of the thumb.

5. The orthosis according to claim 1, wherein, when the orthosis is worn on the hand, motion of the thumb is restricted to a percentage in a range of from 5% to 95%, of the wearers total range of motion.

6. The orthosis according to claim 1, wherein, when the orthosis is worn on the hand, the thumb metacarpal section extends over the palmar side of the metacarpophalangeal joint.

7. The orthosis according to claim 1, wherein when the orthosis is worn on the hand, the connection between the thumb metacarpal section and the metacarpus section is located on a dorsal side of the hand.

8. The orthosis according to claim 1, wherein the thumb section comprises an open loop.

9. The orthosis according to claim 1, wherein the metacarpus section, when the orthosis is worn on the hand, extends on a palmar side of the hand.

10. The orthosis according to claim 9, wherein the metacarpus section extends proximal to the MCP joints of digits 2 to 5.

11. The orthosis according to claim 1, wherein the orthosis is made from a single piece.

12. Orthosis (1) according to any one of the preceding claims, which is made from a single and/or homogenous material or from a composite material and/or comprises sections of a softer material and/or of a material in a different color.

13. The orthosis according to claim 1, wherein the width and/or the thickness of the orthosis varies along its length.

14. The orthosis according to claim 13, wherein the width is in a range of from 3 to 50 mm.

15. The orthosis according to claim 13, wherein the thickness is in a range of from 1 to 15 mm.

16. The orthosis according to claim 1, wherein, when worn on the hand, the orthosis also restrictions motion of the metacarpophalangeal joint of the thumb.

17. The orthosis according to claim 1, wherein the metacarpus section fits around the proximal phalanx of the thumb.

18. The orthosis according to claim 3, wherein the thumb metacarpal section extends helically between the metacarpus section and the thumb section over at least 180°.

19. The orthosis according to claim 3, wherein, when the orthosis is worn on the hand, motion of the thumb is restricted to a percentage in a range from 40% to 60%.

20. The orthosis according to claim 11, wherein the orthosis is made from a plastically deformed plate, strip or bar, or a continuous molded or 3D printed, element.

Description

[0030] FIGS. 1 to 3 are perspective views of a first embodiment of the orthosis according to the present invention, worn on a hand and with the metacarpus section extending on the palmar side of the hand.

[0031] FIGS. 4 to 7 are perspective views of the first embodiment of the orthosis, removed from the hand.

[0032] FIG. 8 is a graph illustrating different degrees of resilience.

[0033] FIG. 9 is a perspective view of a second embodiment of the orthosis according to the present invention, worn on a hand and with the metacarpus section extending on the dorsal side of the hand.

[0034] FIGS. 1 to 3 show a first orthosis 1 according to the present invention, worn on a hand 2 to restrict motion of the carpometacarpal joint, CMCj, and the metacarpophalangeal joint, MCPj, of the thumb 2-1. FIGS. 4 to 7 show the same orthosis removed from the hand 2. The orthosis 1 comprises a metacarpus section 3, which, when the orthosis is worn on a hand, extends across the metacarpals of digits 2-5, i.e., the index finger (digit 2; reference sign 2-2 in the Figures), middle finger (digit 3; 2-3), ring finger (digit 4; 2-4) and little finger (digit digit 5; 2-5), and a thumb section 4. The thumb section 4 is curved in shape and fits around the proximal phalanx 6 of the thumb 2-1, leaving the distal phalanx of the thumb free.

[0035] The orthosis is a single piece of a thermoplastic material, such as cellulose acetate or polyamide, and made by molding or additive manufacturing followed by polishing.

[0036] The thumb section 4 is connected to the metacarpus section 3 via a thumb metacarpal section 7 that, when the orthosis 1 is worn on a hand 2, extends along or around the thumb metacarpal (MCPJ) 8.

[0037] In this example, the metacarpus section 3 extends on the palmar side of the hand, follows the shape of the palm of the hand, and ‘hooks’ around the ulnar and radial sides of the hand. The metacarpus section is open on one side, in this example on the dorsal side of the hand, to facilitate placing it on the hand. Once in place, the metacarpus section provides the basis for supporting the resilient thumb metacarpal section and the thumb section.

[0038] The thumb section 4 consists of an open loop which, when the orthosis is worn on a hand, surrounds the thumb, between the MCP and IP thumb joints. The small opening allows the thumb loop circumference to flex, facilitating placing and removing of the orthosis.

[0039] As best shown in FIGS. 1 and 6, the thumb metacarpal section 7 is cantilevered to the metacarpus section 3 and extends helically between the metacarpus section 3 and the thumb section 4, over almost a full turn. In this example, the thumb metacarpal section 7 transitions to the metacarpus section 3 at its proximal end and there are no other connections between the two sections 7, 3. As the orthosis was made in a single piece, the connection is not discrete but instead a continuous transition between the two sections. The transition is roughly indicated by means of a line, T1, in FIG. 6. The same is true for the transition between the thumb section 4 and the thumb metacarpal section 7, which is indicated, in FIG. 6, by a second line, T2.

[0040] FIG. 8 is a graph that schematically illustrates the reaction force on the thumb section dependent on flexion on the thumb, wherein curve A represents a material and/or construction that has a relatively high stiffness in the direction of flexion, whereas curve B represents a material and/or construction that has a relatively low stiffness in the direction of flexion.

[0041] The orthosis according to the present invention provides supported motion of the thumb, while reducing the risk of pain or damage. The wearer can still move his/her thumb by applying force in a certain direction and elastically deforming the orthosis. When the wearer stops applying force, resilience causes the splint to return to its rest position and, in doing so, guides the thumb to its natural position. The orthosis can be compact, not bulky, unobtrusive, and when a material having a low thermal conductivity is used, feels warm. The construction in the example above requires no closure.

[0042] In an example, a patient has degenerative arthritis degree 2 (Kellgren-Lawrence classification) in the CMC1 and MCP1 joints of his right hand. The wrist and other finger joints have no arthritis. The patient is a male, 36 years old, and works as a farmer, which implies that most of his work is intensive manual labor. There is no limitation in the range of motion (ROM), he is able to exert a pinch force, with his right thumb of 12 kilograms, and during manual labour pain, measured in accordance with the Numerical Rating Scale (NRS), is up to 8/10. To properly support this man's thumb, the orthosis needs to limit both the CMC1 and MCP1 joints. The total ROM needs to be reduced by 80% at a force of 7.5 kg. This ROM limitation means that the total allowed flexion ROM with the orthosis in the CMC1 joint is 1 cm when applying a force of 7.5 kg.

[0043] The invention is not restricted to the above-described embodiments, which can be varied in a number of ways within the scope of the claims. E.g., instead of open on the dorsal side of the hand, the metacarpus section could be closed or open on the palmar side of the hand, as illustrated in FIG. 9.