Relating to footwear

1. An article of footwear comprising a heel portion for supporting a heel of a foot of a wearer, the heel portion defining a channel extending uninterrupted from a first opening situated at a first laterally-facing surface of the heel portion to a second opening situated at a second laterally-facing surface of the heel portion, the first and second laterally-facing surfaces being opposed to one another, the article of footwear further comprising a fastening means for fastening the article of footwear to the foot of the wearer, the fastening means being arranged to extend through said channel and, in use of the footwear, is fastenable around the dorsal region of the foot of the wearer of the article of footwear wherein the heel portion comprises:

a sleeve portion positioned and arranged to surround and define the channel; and

a body comprising a conduit within which at least a stem of the sleeve portion is inserted;

wherein an internal cross-sectional profile of the conduit and an external cross-sectional profile of the stem of the sleeve portion inserted into the conduit, closely conform to one another so that the stem of the sleeve portion is securely embedded within the conduit.

2. The article of footwear according to claim 1 , wherein the channel is positioned and arranged to be accessed by a wearer when the article of footwear is being worn by the wearer, thereby allowing the wearer to convert the footwear between a slip-on and non-slip-on type without removing the article of footwear.

3. The article of footwear according to claim 2 , wherein the first and second laterally-facing surfaces are external surfaces of the heel portion that face outward, and away from one another.

4. The article of footwear according to claim 1 , having only a single channel through which the fastening means extends, the fastening means, when fastened, forming a complete loop that passes through the channel and, in use of the footwear, also around the foot of the wearer to retain the footwear to the foot of the wearer.

5. The article of footwear according to claim 1 , wherein the fastening means comprises a fastener situated at one end of the fastening means and a complementary fastening structure at another end, the fastener and the complementary fastening structure being releasably connectable with one another, the connection of the fastener and the complementary fastening structure forming a loop, and disconnection breaking that loop.

6. The article of footwear according to claim 1 , wherein a bore profile of the channel is substantially regular between the first and second openings, the channel comprising smooth internal walls allowing a fastening means manually urged through one of the first and second openings to be guided by the internal walls so as to exit from the other of the first and second openings.

7. The article of footwear according to claim 1 , wherein the stem of the sleeve portion is securely embedded within the conduit via an interference fit, at least one of the ends of the sleeve portion is situated at an external region of the body of the heel portion to define at least one of the first and second openings of the heel portion, the sleeve portion is constructed of a material that is stronger than the material from which the body is constructed, the sleeve portion defines a mantle around at least one of the first and second openings of the channel, the sleeve portion is constructed from a plurality of components, a first component comprising a first portion of the stem and a second component comprising a second portion of the stem, the first and second components being fitted by driving them into the conduit of body via respective first and second conduit apertures, and at least one of the first and second components are cast from an integral piece of material and the sleeve portion comprises one or more flanges, each flange being located at a respective end of the sleeve portion.

8. The article of footwear according to claim 7 , wherein at least one of the flanges has an external cross-sectional profile that prevents insertion into the conduit of the body so as to limit the depth of insertion of the sleeve portion into the conduit of the body, at least one of the flanges defines a mantle around a respective opening of the channel, at least one of the flanges comprises an inwardly-facing shoulder, shaped and oriented in complement with a respective outwardly-facing surface of the body to facilitate even engagement between the flange and the body, and at least one of the flanges comprises an outwardly-facing region that is rounded to avoid sharp edges being presented on an exterior of the article of footwear.

9. The article of footwear according to claim 1 , wherein the heel portion comprises a core extending between a heel seat of the article of footwear, and the ground on which the article of footwear stands in normal use, with the channel extending across a path that avoids the core.

10. The article of footwear according to claim 1 , wherein a cross-sectional profile of the channel tapers inwardly towards the ground, tapering in conformity with a corresponding tapering of the heel portion.

11. The article of footwear according to claim 1 , wherein a cross-sectional profile of the channel is of a broadly tear-drop shape.

12. The article of footwear according to claim 1 , wherein the channel is situated at the front of the heel portion, close to a transition between the heel portion and an arch of the article of footwear, with the channel extending laterally across the width of the heel portion of the footwear, the channel being oriented such that ends of a fastening means that emerge from the channel extend laterally away from one another and also from a foot of the wearer of the article of footwear.

13. The article of footwear according to claim 1 , wherein the cross-sectional area of a central portion of the fastening means that extends through the channel is less than 60% of the cross-sectional size of the bore of the channel.

14. The article of footwear according to claim 1 , wherein the article of footwear comprises an upper for covering at least a portion of an upper part of a wearer's foot, the upper being arranged to form an interference fit with a foot of the wearer of the article of footwear, the upper presenting a substantially continuous external surface.

15. The article of footwear according to claim 1 , wherein the first and second openings are situated at laterally opposed positions on the heel portion at substantially the same height from the ground on which the article of footwear stands in normal use, with the channel being level relative to the ground on which the footwear stands in normal use.

16. The article of footwear according to claim 1 , wherein the channel is situated closer to a heel seat of the article of footwear than the ground.

17. An article of footwear of a slip-on type arranged for conversion to a non-slip-on type, the article of footwear comprising a heel portion for supporting a heel of a foot of a wearer, the heel portion defining a channel extending from a first opening situated at a first laterally-facing surface of the heel portion to a second opening situated at a second laterally-facing surface of the heel portion, the first and second laterally-facing surfaces being opposed to one another, conversion to a non-slip-on type of footwear resulting from manual threading of a fastening means through said channel, the fastening means being arranged to loop around the foot of the wearer of the article of footwear, in use, so as to fasten the article of footwear thereto wherein the heel portion comprises:

a sleeve portion positioned and arranged to surround and define the channel; and

a body comprising a conduit within which at least a stem of the sleeve portion is inserted;

wherein an internal cross-sectional profile of the conduit and an external cross-sectional profile of the stem of the sleeve portion inserted into the conduit, closely conform to one another so that the stem of the sleeve portion is securely embedded within the conduit.

18. The article of footwear according to claim 11 , wherein the point of the tear-drop faces down towards the ground on which the article of footwear stands in normal use.