Boot carriage for repositioning a surgical boot along a support rod

1. A limb support comprising

a support structure configured to be mounted to a patient support apparatus, the support structure including a spar having a longitudinal axis, and a guide tube having a longitudinal axis that is parallel to the longitudinal axis of the spar,

a limb rest configured to support the limb of a patient supported on the patient support apparatus, and

a coupler supported from the spar and supporting the limb rest, the coupler having a single release that is manually actuable to permit a user to move the release between a locked position and a released position, wherein when the release is in the released position the limb support is simultaneously adjustable relative to the spar with at least two degrees of freedom,

wherein at least a portion of the coupler engages the guide tube such that rotation of the coupler about the longitudinal axis of the spar is precluded by the engagement of the portion of the coupler with the guide tube regardless of the position of the release.

2. The limb support of claim 1 , wherein when the release is in the released position, the limb rest is simultaneously adjustable relative to the spar with at least four degrees of freedom.

3. The limb support of claim 2 , wherein the release is only operable to lock three of the four degrees of freedom.

4. The limb support of claim 1 , wherein when the release is in the released position, the limb rest is simultaneously adjustable relative to the spar in at least three degrees of freedom.

5. The limb support of claim 1 , wherein the release is manually actuable between a released position permitting movement of the limb rest about a first axis, about a second axis, and along the spar, and a locked position preventing movement of the limb rest about the first axis, about the second axis, and along the spar.

6. A limb support, comprising

a support structure configured to be mounted to a patient support apparatus, the support structure including a spar having a longitudinal axis, and a guide tube having a longitudinal axis that is parallel to the longitudinal axis of the spar,

a limb rest configured to support the limb of a patient supported on the patient support apparatus, and

a coupler supported from the spar and supporting the limb rest, the coupler having a single release that is manually actuable to permit a user to move the release between a locked position and a released position, wherein when the release is in the released position the limb support is simultaneously adjustable relative to the spar with at least four degrees of freedom,

wherein the release is only operable to lock three of the four degrees of freedom, and

wherein the coupler comprises a floating lock member, a biased locking assembly, a fixed lock member, a plurality of wedge members, a plurality of fixed plates, and a shaft engaged with at least one fixed plate, wherein the floating lock member engages the wedge members and the wedge members engage the fixed lock member such that the wedge members induce a load between the wedge members and the fixed plates such that the load of the bias member is transferred through the wedge members to the plates, the plates thereby inducing a load in the shaft.

7. The limb support of claim 6 , wherein the release is operable to disengage the floating lock member from the wedge members so as to reduce the load induced in the shaft.

8. The limb support of claim 7 , wherein the load induced in the shaft is operable to lock the coupler to the spar.

9. The limb support of claim 8 , wherein the reduction in the load in the shaft releases the coupler from the spar such that the coupler is moveable along the longitudinal axis of the spar.

10. The limb support of claim 6 , wherein the wedge members are coupled together by a bias structure that urges the wedge members to engage the floating lock member and fixed lock member.

11. The limb support of claim 10 , wherein the bias structure coupling the wedge members is insufficient to prevent movement of the limb rest relative to the spar.

12. The limb support of claim 11 , wherein the coupler includes a carriage that is supported on the spar, the carriage including a frame and a lock moveable relative to the frame, the lock being pivoted relative to the frame to secure the carriage to the spar when the load is induced in the shaft.

13. The limb support of claim 12 , wherein the carriage further includes a bias member that is configured to resist the load induced in the shaft.

14. The limb support of claim 13 , wherein the load induced in the shaft overcomes the bias of the bias member of the carriage when the load is induced in the shaft by the biased locking assembly.

15. The limb support of claim 14 , wherein the bias of the bias member is sufficient to release the lock of the carriage when the load in the shaft is removed.

16. The limb support of claim 6 , wherein the release includes a cam that is rotated to cause the floating lock member to disengage the wedge members.

17. The limb support of claim 16 , wherein the limb rest is rotatable about a third axis, regardless of the position of the release.

18. A limb support, comprising

a support structure configured to be mounted to a patient support apparatus, the support structure including a spar having a longitudinal axis, and a guide member having a longitudinal axis that is parallel to the longitudinal axis of the spar,

a limb rest configured to support the limb of a patient supported on the patient support apparatus, and

a coupler supported from the spar and supporting the limb rest, the coupler having a single release that is manually actuable to permit a user to move the release between a locked position and a released position, wherein when the release is in the released position the limb support is simultaneously adjustable relative to the spar with at least two degrees of freedom, wherein rotation of the coupler about the longitudinal axis of the spar is precluded by the guide member,

wherein the release is manually actuable between a released position permitting movement of the limb rest about a first axis, about a second axis, and along the spar, and a locked position preventing movement of the limb rest about the first axis, about the second axis, and along the spar, and

wherein the release is configured such that manual actuation achieves a mechanical advantage that overcomes bias of a biased locking assembly.

19. The limb support of claim 18 , wherein the coupler includes a carriage that engages the spar.

20. The limb support of claim 19 , wherein the carriage also engages the guide member.

21. The limb support of claim 20 , wherein the carriage includes a bias member that biases at least a portion of the carriage into engagement with the guide member.

22. The limb support of claim 21 , wherein the carriage further includes at least one needle bearing that engages the guide member.

23. The limb support of claim 21 , wherein the carriage includes at least one bearing member that is biased to engage the guide member.

24. The limb support of claim 23 , wherein at least one wedge member includes a feature that limits the range of motion of the limb rest about the first axis.