Orthosis with distraction through range of motion

• US 5,453,075 A
• Filed: 08/26/1994
• Issued: 09/26/1995
• Est. Priority Date: 07/30/1990
• Status: Expired due to Term

• Current Assignee: Bonutti Research Incorporated (Bonutti IP LLC)
• Original Assignee: Peter M. Bonutti
• Inventors: Zitzmann, Gary E., Bonutti, Peter M.
• Primary Examiner(s): DVORAK, LINDA C
• Application Number:
  US08/297,258
• Time in Patent Office: 396 Days
• Field of Search: 602/5, 602/16, 602/20, 602/23, 602/26, 602/32, 602/36-38, 482/124, 482/130, 482/139, 601/23, 601/33, 601/34, 601/40, 128/898
• US Class Current: 602/16
• CPC Class Codes: A61F 2005/0137 with two parallel pivots
• CPC Class Codes: A61F 2005/0139 geared
• CPC Class Codes: A61F 2005/0153 combining rotational and stretching movements
• CPC Class Codes: A61F 5/0102 specially adapted for correcting deformities of the limbs or for supporting them; Ortheses, e.g. with articulations
• CPC Class Codes: A61F 5/0123 for the knees A61F5/0106 takes precedence
• CPC Class Codes: A61F 5/013 for the arms, hands or fingers A61F5/0118 takes precedence
• CPC Class Codes: A61H 1/024 Knee A61H1/0255 takes precedence
• CPC Class Codes: A61H 1/0277 Elbow
• CPC Class Codes: G04F 5/025 Electronic metronomes rhytem generation for electrophonic musical instruments G10H1/36
• CPC Class Codes: G04G 9/085 provided with date indication

Abstract

An orthosis for stretching tissue that limits compressive forces on the soft tissue around a joint during movement of the joint. The orthosis includes two relatively pivotable cuff arms with a cuff on each arm. The cuffs clamp onto the body portions on either side of the joint. The pivot axis of the cuff arms is spaced from the pivot axis of the joint, so that movement of the cuff arms to extend the joint results in distractive forces being applied to the joint. The cuffs are selectively moved on the cuff arms, during extension and flexion, to provide the proper amount of distractive forces to the joint and to limit compressive forces on the joint. A mechanical advantage is gained through the use of a gear drive mechanism for transmitting to the joint the force applied by the patient. This allows the orthosis to be relatively small and light weight. The orthosis also provides a portable system for continuous passive motion therapy for a joint. The orthosis may be operated by a manual plus electric drive cycling it between extremes of motion. Provision is made for monitoring the range of motion or the force applied.

Claims

1. A method of effecting relative movement between first and second body portions interconnected by a joint, said method comprising the steps of connecting a first cuff and a first cuff arm with the first body portion, connecting a second cuff and a second cuff arm with the second body portion, bending the joint by transmitting force through the first and second cuffs to the first and second body portions, and moving the first cuff along the first cuff arm during bending of the joint.

2. A method as set forth in claim 1 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes engaging an outer side surface of the first body portion with an inner side surface of the first cuff, said method further including gripping the first body portion with the first cuff with sufficient force to prevent relative movement between the outer side surface of the first body portion and the inner side surface of the first cuff during performance of said step of moving the first cuff along the first cuff arm.

3. A method as set forth in claim 1 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with a first end portion of the first cuff arm adjacent to the joint, said step of connecting a second cuff and a second cuff arm with the second body portion includes connecting the second cuff arm with the second body portion with a first end portion of the second cuff arm adjacent to the joint and spaced from the first end portion of the first cuff arm and with a base link extending between the first end portions of the first and second cuff arms, said step of bending the joint includes pivoting the first cuff arm about a pivot connection between the base link and the first end portion of the first cuff arm and pivoting the second cuff arm about a pivot connection between the base link and the first end portion of the second cuff arm, the pivot connections between the first and second cuff arms and the base link being spaced apart on the base link.

4. A method as set forth in claim 1 wherein the joint and the first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said step of bending the joint includes transmitting force from a location in the outer sector to the first and second cuff arms, said step of moving the first cuff along the first cuff arm includes transmitting force from the location in the outer sector to the first cuff.

5. A method as set forth in claim 1 wherein the joint and the first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said step of bending the joint includes pivoting the first cuff arm about a first pivot connection which is disposed in the outer sector and pivoting the second cuff arm about a second pivot connection which is disposed in the outer sector and is spaced from the first pivot connection.

6. A method as set forth in claim 5 wherein said step of connecting the first cuff and the first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with the first cuff arm disposed in the outer sector, said step of connecting the second cuff and the second cuff arm with the second body portion includes connecting the second cuff arm with the second body portion with the second cuff arm disposed in the outer sector.

7. A method as set forth in claim 2 wherein said step of bending the Joint includes pivoting the first cuff arm about an axis which is offset from a central portion of the joint.

8. A method as set forth in claim 1 wherein said step of bending the joint includes bending the joint in extension, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction toward the joint.

9. A method as set forth in claim 8 wherein said step of bending the joint in extension includes subjecting the joint to a limited amount of distraction.

10. A method as set forth in claim 1 wherein said step of bending the joint includes bending the joint in flexion, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction away from the joint.

11. A method as set forth in claim 10 wherein said step of bending the joint in flexion includes subjecting the joint to a limited amount of distraction.

12. A method as set forth in claim 1 further including the step of providing an indication of the degree of flexion of the joint during performance of said step of bending the joint.

13. A method as set forth in claim 1 further including the step of adjusting an angle between one of the cuff arms and the one of the cuffs attached thereto by rotating the one cuff attached to the one cuff arm about a connection between the one cuff and the one cuff arm.

14. A method as set forth in claim 1 further including the steps of manually moving a member to effect the transmittal of force from the member through a mechanism to the first and second cuff arms, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting force transmitted through the mechanism to the first and second cuff arms and from the first and second cuff arms to the first and second cuffs.

15. A method as set forth in claim 1 wherein said step of manually moving a member is performed by a person having the first and second body portions with which the first and second cuffs are connected.

16. A method as set forth in claim 1 further including the step of operating an electric motor to effect the transmittal of force from the electric motor through a mechanism to the first and second cuff arms, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting the force transmitted through the mechanism to the first and second cuff arms to the first and second cuffs.

17. A method as set forth in claim 1 wherein said step of bending the joint includes providing relative movement between the first and second cuffs to bend the joint in one direction, allowing body tissue to stretch by retaining the cuffs against movement relative to each other after having performed said step of providing relative movement between the first and second cuffs, and, thereafter, providing additional relative movement between the first and second cuffs to further bend the joint in the one direction.

18. A method as set forth in claim 1 wherein said step of bending the joint includes bending the joint to one end of the joint'"'"'s range of motion, holding the joint against movement from the one end of the joint'"'"'s range of motion for a period of time, and then bending the joint to an end of the joint'"'"'s range of motion opposite to the one end.

19. A method as set forth in claim 1 further including the step of operating a fluid motor to effect the transmittal of force from the fluid motor through a mechanism to the first and second cuff arms, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting the force transmitted through the mechanism to the first and second cuff arms to the first and second cuffs.

20. A method as set forth in claim 1 wherein said steps of connecting a first cuff with the first body portion and connecting the second cuff with the second body portion includes connecting at least one of the cuffs with a pin which projects from a bone in one of the body portions, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting force from the one cuff to the pin and transmitting force from the pin to the bone in the one of the body portions.

21. A method as set forth in claim 1 wherein said step of bending the joint by transmitting force through the first and second cuffs includes transmitting force through a mechanism by operating the mechanism in a first direction to bend the joint, said method further including retaining the joint in a condition to which it is bent with resistance provided by the mechanism to operation in a direction opposite to the first direction by force transmitted from the first and second body portions to the mechanism.

22. A method as set forth in claim 1 wherein said step of bending the joint by transmitting force through the first and second cuffs includes actuating a ratchet drive mechanism in a first direction and retaining the first and second cuffs against relative movement with the ratchet drive mechanism upon interruption of said step of actuating the ratchet drive mechanism.

23. A method as set forth in claim 22 wherein said step of actuating a ratchet drive mechanism is performed by a person having the first and second body portions with which the first and second cuffs are connected.

24. A method as set forth in claim 1 wherein said step of bending the joint includes effecting relative movement between the first and second cuffs in a first direction from a first position relative to each other to a second position relative to each other, interrupting said step of bending the joint for a period of time, and, thereafter, resuming said step of bending the joint by effecting relative movement between the first and second cuffs in the first direction from the second position relative to each other to a third position relative to each other.

25. A method as set forth in claim 1 wherein said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes applying force to a mechanism connected with the first and second cuffs and limiting the force applied to the mechanism to a predetermined maximum force.

26. A method as set forth in claim 25 wherein said step of applying force to a mechanism includes applying torque to the mechanism, said step of limiting the force applied to the mechanism includes limiting the torque applied to the mechanism.

27. A method as set forth in claim 25 wherein said step of applying force to the mechanism includes operating an electric motor to drive the mechanism, said step of limiting the force applied to the mechanism includes limiting the force applied to the mechanism by the electric motor during operation of the electric motor.

28. A method as set forth in claim 25 wherein said step of applying force to a mechanism is performed by a person having the first and second body portions with which the first and second cuffs are connected and includes manually applying force to an input to the mechanism, said step of limiting the force applied to the mechanism includes limiting the force transmitted between the input to the mechanism and the mechanism.

29. A method as set forth in claim 1 further including the step of moving the second cuff along the second cuff arm simultaneously with movement of the first cuff along the first cuff arm during bending of the joint.

30. A method as set forth in claim 29 wherein said steps of moving the first and second cuffs along the first and second cuff arms includes moving the first cuff along the first cuff arm in a direction toward the joint and moving the second cuff along the second cuff arm in a direction toward the joint simultaneously with movement of the first cuff along the first cuff arm in a direction toward the joint.

31. A method as set forth in claim 30 wherein said steps of moving the first and second cuffs along the first and second cuff arms includes moving the first cuff along the first cuff arm in a direction away from the joint and moving the second cuff along the second cuff arm in a direction away from the joint simultaneously with movement of the first cuff along the first cuff arm in a direction away from the joint.

32. A method as set forth in claim 1 further including the step of manually actuating a linkage to transmit force to effect relative movement between the first and second cuff arms and to simultaneously therewith effect movement of first cuff along the first cuff arm.

33. A method as set forth in claim 32 wherein said step of manually actuating a linkage is performed by a person having the first and second body portions with which the first and second cuffs are connected.

34. A method as set forth in claim 33 wherein said step of manually actuating a linkage to transmit force to effect relative movement between the first and second cuff arms includes manually actuating the linkage in a first direction to effect relative movement between the first and second cuff arms to first positions relative to each other, maintaining the first and second cuff arms stationary in the first positions relative to each other for a predetermined length of time, and, thereafter, manually actuating the linkage in the first direction to again effect relative movement between the first and second cuff arms.

35. A method as set forth in claim 1 wherein said step of bending the joint by transmitting force through first and second cuffs to the first and second body portions includes moving an actuator member along a path, transmitting force from the actuator member through a first link to the first cuff arm to pivot the first cuff arm in a first direction about a pivot connection between the first cuff arm and a base link as the actuator member moves along the path, and transmitting force from the actuator member through a second link to the second cuff arm to pivot the second cuff arm in a second direction about a pivot connection between the second cuff arm and the base link as the actuator member moves along the path, said step of moving the first cuff along the first cuff arm during bending of the joint includes moving the first cuff along the first cuff arm under the influence of force transmitted from the actuator member through the first link to the first cuff as the actuator member moves along the path.

36. A method as set forth in claim 35 wherein said step of moving the actuator member along a path includes moving the actuator member along a path which extends through the joint.

37. A method as set forth in claim 35 wherein said step of moving the actuator member along a path includes effecting relative rotation between internally and externally threaded members to move one of the threaded members connected with the actuator member relative to the other threaded member.

38. A method as set forth in claim 35 further including the step of moving the second cuff along the second cuff arm during bending of the joint, said step of moving the second cuff along the second cuff arm during bending of the joint includes moving the second cuff along the second cuff arm under the influence of force transmitted from the actuator member through the second link to the second cuff as the actuator member moves along the path.

39. A method of effecting relative movement between first and second body portions interconnected by a joint, said method comprising the steps of connecting a first cuff and a first cuff arm with the first body portion, connecting a second cuff and a second cuff arm with the second body portion with the first and second cuff arms interconnected by a base link, moving an actuator member along a path extending transverse to the base link, transmitting force from the actuator member through a first link to the first cuff arm to pivot the first cuff arm in a first direction of rotation about a pivot connection between the first cuff arm and the base link as the actuator member moves along the path, transmitting force from the actuator member through a second link to the second cuff arm to pivot the second cuff arm in a second direction of rotation about a pivot connection between the second cuff arm and the base link as the actuator member moves along the path, the second direction of rotation being opposite from the first direction of rotation, transmitting force from the first and second cuff arms to the first and second cuffs as the actuator member moves along the path, and bending the joint under the influence of the force transmitted from the first and second cuff arms to the first and second cuffs as the actuator member moves along the path.

40. A method as set forth in claim 39 further including the step of transmitting force from the first link to the first cuff to move the first cuff along the first cuff arm as the actuator member moves along the path.

41. A method as set forth in claim 40 further including the step of transmitting force from the second link to the second cuff to move the second cuff along the second cuff arm as the actuator member moves along the path.

42. A method as set forth in claim 39 wherein said step of moving an actuator member along a path extending transverse to the base link includes moving the actuator member along a linear path which extends through the base link.

43. A method as set forth in claim 39 wherein said step of transmitting force from the actuator member through a first link to the first cuff arm to pivot the first cuff arm in a first direction of rotation includes pivoting the first link about a pivot connection between the first link and the actuator member and pivoting the first link about a pivot connection between the first link and the first cuff arm, said step of transmitting force from the actuator member through a second link to the second cuff arm to pivot the second cuff arm in a second direction of rotation includes pivoting the second link about a pivot connection between the second link and the actuator member and pivoting the second link about a pivot connection between the second link and the second cuff arm.

44. A method as set forth in claim 39 wherein said step of transmitting force from the actuator member through a first link to the first cuff arm to pivot the first cuff arm in a first direction of rotation includes pivoting the first link about a pivot connection between a portion of the first link and the actuator member and pivoting the first link about a pivot connection between the first cuff arm and a portion of the first link, said step of transmitting force from the actuator member through a second link to the second cuff arm to pivot the second cuff arm in a second direction of rotation includes pivoting the second link about a pivot connection between a portion of the second link and the actuator member and pivoting the second link about a pivot connection between the second cuff arm and a portion of the second link, said method further including the steps of moving the first cuff along the first cuff arm under the influence of force transmitted from the first link to the first cuff during pivoting of the first link about the pivot connection between the first cuff arm and the first link, and moving the second cuff along the second cuff arm under the influence of force transmitted from the second link to the second cuff during pivoting of the second link about the pivot connection between the second cuff arm and the second link.

45. A method as set forth in claim 44 wherein said step of moving an actuator member along a path extending transverse to the base link includes moving the actuator member toward the base link, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction away from the base link, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction away from the base link.

46. A method as set forth in claim 44 wherein said step of moving an actuator along a path extending transverse to the base link includes moving the actuator member away from the base link, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction toward the base link, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in direction toward the base link.

47. A method as set forth in claim 39 wherein said step of moving an actuator member along a path transverse to the base link includes providing relative rotation between internally and externally threaded members.

48. A method as set forth in claim 39 wherein said step of moving an actuator member along a path transverse to the base link includes manually applying force to an input member to effect movement of the actuator member along the path under the influence of force transmitted from the input member.

49. A method as set forth in claim 39 further including the step of supporting a motor on the base link, said step of moving an actuator member along a path transverse to the base link includes transmitting force from the motor to the actuator member.

50. A method as set forth in claim 39 wherein said step of transmitting force from the actuator member through the first link to the first cuff arm to pivot the first cuff arm in a first direction of rotation about a pivot connection between the first cuff arm and the base link includes pivoting the first cuff arm about a first axis which is offset from a central portion of the joint, the step of transmitting force from the actuator member through a second link to the second cuff arm to pivot the second cuff arm in a second direction about a pivot connection between the second cuff arm and the base link includes pivoting the second cuff arm about a second axis which is offset from a central portion of the joint and is offset from the first axis.

51. A method as set forth in claim 39 further including providing an indication of the angular relationship between the first and second cuff arms during performance of said steps of transmitting force from the actuator member through the first link to the first cuff arm to pivot the first cuff arm in a first direction of rotation and transmitting force from the actuator member through the second link to the second cuff arm to pivot the second cuff arm in a second direction of rotation.

52. A method as set forth in claim 39 further including the step of adjusting the position of the first cuff relative to the first cuff arm by pivoting the first cuff about an axis which extends through the first cuff arm in a direction transverse to an axis about which the first cuff arm pivots about the pivot connection between the first cuff arm and the base link.

53. A method as set forth in claim 39 wherein said step of moving an actuator member along a path extending transverse to the base link includes manually moving an input member to effect the transmittal of force from the input member through a mechanism to the actuator member.

54. A method as set forth in claim 53 wherein said step of manually moving an input member is performed by a person having the first and second body portions with which the first and second cuffs are connected.

55. A method as set forth in claim 39 wherein said step of moving an actuator member along a path extending transversely to the base link includes moving the actuator member along the path in a first direction to a first position, retaining the actuator member in the first position for a length of time sufficient to allow body tissue to stretch, and, thereafter, moving the actuator member along the path in the first direction away from the first position.

56. A method as set forth in claim 39 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes connecting the first cuff with a pin which projects from a bone in the first body portion, said step of bending the joint includes transmitting force from the first cuff to the pin and transmitting force from the pin to the bone in the first body portion.

57. A method as set forth in claim 39 wherein said step of moving an actuator member along a path extending transverse to the base link includes applying force to a mechanism connected with the actuator member and limiting the force applied to the mechanism to a predetermined force.

58. A method as set forth in claim 39 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes engaging an outer side surface of the first body portion with an inner side surface of the first cuff, said step of connecting a second cuff and a second cuff arm with the second body portion includes engaging an outer side surface of the second body portion with an inner side surface of the second cuff, said method further including moving the first cuff along the first cuff arm while bending the joint and while gripping the first body portion with the first cuff with sufficient force to prevent movement between the outer side surface of the first body portion and the inner side surface of the first cuff during movement of the first cuff along the first cuff arm, and moving the second cuff along the second cuff arm while bending the joint and while gripping the second body portion with the second cuff with sufficient force to prevent movement between the outer side surface of the second body portion and the inner side surface of the second cuff during movement of the second cuff along the second cuff arm.

59. A method as set forth in claim 39 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with a first end portion of the first cuff arm adjacent to the joint, said step of connecting a second cuff and a second cuff arm with the second body portion includes connecting the second cuff arm with the second body portion with a first end portion of the second cuff arm adjacent to the joint and spaced from the first end portion of the first cuff arm.

60. A method as set forth in claim 39 wherein the joint and the first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said step of moving the actuator member along a path extending transverse to the base link includes moving the actuator member along a portion of the path disposed in the outer sector.

61. A method as set forth in claim 60 wherein said step of transmitting force from the actuator member through a first link to the first cuff arm to pivot the first cuff arm in a first direction of rotation about a pivot connection between the first cuff arm and the base link includes pivoting the first cuff arm about a pivot connection which is disposed in the outer sector, said step of transmitting force from the actuator member through a second link to the second cuff arm to pivot the second cuff arm in a second direction of rotation about a pivot connection between the second cuff arm and the base link includes pivoting the second cuff arm about a pivot connection which is disposed in the outer sector.

62. A method of effecting relative movement between first and second body portions interconnected by a joint, said method comprising the steps of connecting a first cuff and a first cuff arm with the first body portion, connecting a second cuff and a second cuff arm with the second body portion, thereafter, moving an actuator member relative to the first and second cuff arms, pivoting the first cuff arm under the influence of force transmitted from the actuator member through a first link connected with the actuator member and first cuff arm during movement of the actuator member, moving the first cuff along the first cuff arm under the influence of force transmitted from the actuator member during movement of the actuator member, pivoting the second cuff arm under the influence of force transmitted from the actuator member through a second link connected with the actuator member and second cuff arm during movement of the actuator member, and moving the second cuff along the second cuff arm under the influence of force transmitted from the actuator member during movement of the actuator member.

63. A method as set forth in claim 62 wherein said step of moving the first cuff along the first cuff arm is performed simultaneously with performance of said step of moving the second cuff along the second cuff arm.

64. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes pivoting the first and second links under the influence of force transmitted to portions of the first and second links from the actuator member, said step of moving the first cuff along the first cuff arm includes moving the first cuff under the influence of force transmitted to the first cuff from a portion of the first link during pivotal movement of the first link under the influence of force transmitted to a portion of the first link from the actuator member, said step of moving the second cuff along the second cuff arm includes moving the second cuff under the influence of force transmitted to the second cuff from a portion of the second link during pivotal movement of the second link under the influence of force transmitted to a portion of the second link from the actuator member.

65. A method as set forth in claim 62 wherein said step of pivoting the first cuff arm includes pivoting the first cuff arm in a first direction about an axis which is offset from a central portion of the joint and said step of pivoting the second cuff arm includes pivoting the second cuff arm in a second direction which is opposite to the first direction about an axis which is offset from the central portion of the joint.

66. A method as set forth in claim 62 wherein said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction toward the joint, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction toward the joint during movement of the first cuff along the first cuff arm in a direction toward the joint.

67. A method as set forth in claim 62 wherein said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction away from the joint, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction away from the joint during movement of the first cuff along the first cuff arm in a direction away from the joint.

68. A method as set forth in claim 62 further including the step of bending the joint under the influence of force transmitted from the first cuff to the first body portion during pivoting of the first cuff arm and under the influence of force transmitted from the second cuff to the second body portion during pivoting of the second cuff arm.

69. A method as set forth in claim 68 wherein said step of bending the joint includes bending the joint in extension, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction toward the joint during bending of the joint, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction toward the joint during bending of the joint.

70. A method as set forth in claim 69 wherein said step of bending the joint in extension includes subjecting the joint to a limited amount of distraction.

71. A method as set forth in claim 68 wherein said step of bending the joint includes bending the joint in flexion, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction away from the joint during bending of the joint, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction away from the joint during bending of the joint.

72. A method as set forth in claim 71 wherein said step of bending the joint in flexion includes subjecting the joint to a limited amount of distraction.

73. A method as set forth in claim 68 further including the step of providing an indication of the degree of flexion of the joint during performance of said step of bending the joint.

74. A method as set forth in claim 68 wherein said step of bending the joint includes pivoting the first cuff arm in a first direction and pivoting the second cuff arm in a second direction which is opposite to the first direction, allowing body tissue to stretch by retaining the first and second cuff arms against pivotal movement after having performed said steps of pivoting the first cuff arm in a first direction and pivoting the second cuff arm in a second direction, and, thereafter, pivoting the first cuff arm in the first direction and pivoting the second cuff arm in the second direction.

75. A method as set forth in claim 68 wherein said step of bending the joint includes bending the joint to one end of the joint'"'"'s range of motion, holding the joint against movement from the one end of the joint'"'"'s range of motion for a period of time, and then bending the joint to an end of the joint'"'"'s range of motion opposite to the one end.

76. A method as set forth in claim 68 wherein said steps of moving an actuator member relative to the first and second cuff arms and bending the joint include operating a mechanism to move the actuator member in a first direction to bend the joint, said method further including retaining the joint in a condition to which it is bent by resisting movement of the actuator member in a direction opposite to the first direction with resistance provided by the mechanism.

77. A method as set forth in claim 68 wherein said step of moving the actuator member relative to the cuff arms includes moving the actuator member in a first direction from a first position to a second position, interrupting said step of moving the actuator member in a first direction for a period of time upon movement of the actuator member to the second position, and, thereafter, moving the actuator member in the first direction from the second position, said step of bending the joint includes bending the joint in one direction from a first condition to a second condition during movement of the actuator member in the first direction from the first position to the second position, interrupting said step of bending the joint during interruption of said step of moving the actuator member in the first direction, and, thereafter, bending the joint in the one direction from the second condition toward a third condition during movement of the actuator member in the first direction from the second position.

78. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes manually moving an input member to effect the transmittal of force from the input member to the actuator member, said steps of pivoting the first and second cuff arms and moving the first and second cuff arms being performed under the influence of force transmitted from the input member to the actuator member.

79. A method as set forth in claim 78 wherein said step of manually moving the input member is performed by a person having the first and second body portions with which the first and second cuffs are connected.

80. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes operating an electric motor to effect the transmittal of force from the electric motor to the actuator member.

81. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes operating a fluid motor to effect the transmittal of force from the fluid motor to the actuator member.

82. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes transmitting force through a mechanism by operating the mechanism in a first direction, said method further including retaining the actuator member and first and second links against movement with resistance provided by the mechanism to operation in a direction opposite to the first direction by force transmitted from the actuator member to the mechanism.

83. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes applying force to a mechanism connected with the actuator member and limiting the force applied to the mechanism to a predetermined maximum force.

84. A method as set forth in claim 83 wherein said step of applying force to a mechanism includes applying torque to the mechanism, said step of limiting the force applied to the mechanism includes limiting the torque applied to the mechanism.

85. A method as set forth in claim 83 wherein said step of applying force to a mechanism includes operating a motor to drive the mechanism, said step of limiting the force applied to the mechanism includes limiting the force applied to the mechanism by the motor during operation of the motor.

86. A method as set forth in claim 83 wherein said step of applying force to a mechanism is performed by a person having the first and second body portions with which the first and second cuffs are connected and includes manually applying force to an input to the mechanism, said step of limiting the force applied to the mechanism includes limiting the force transmitted between the input to the mechanism and the mechanism.

87. A method as set forth in claim 62 wherein said step of moving an actuator member relative to the first and second cuff arms includes effecting relative rotation between internally and externally threaded members to move one of the threaded members and the actuator member relative to the other threaded member.

88. A method as set forth in claim 62 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes engaging an outer side surface of the first body portion with an inner side surface of the first cuff, said step of connecting a second cuff and a second cuff arm with the second body portion includes engaging an outer side surface of the second body portion with an inner side surface of the second cuff, said method further including gripping the first body portion with the first cuff with sufficient force to prevent movement between the outer side surface of the first body portion and the inner side surface of the first cuff during movement of the first cuff along the first cuff arm, and gripping the second body portion with the second cuff with sufficient force to prevent movement between the outer side surface of the second body portion and the inner side surface of the second cuff during movement of the second cuff along the second cuff arm.

89. A method as set forth in claim 62 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with a first end portion of the first cuff arm adjacent to the joint, said step of connecting a second cuff and a second cuff arm with the second body portion includes connecting the second cuff with the second body portion with a first end portion of the second cuff arm adjacent to the joint and spaced from the first end portion of the first cuff arm and with a base link extending between the first end portions of the first and second cuff arms, said step of pivoting the first cuff arm including pivoting the first cuff arm about a pivot connection between the base link and the first end portion of the first cuff arm, said step of pivoting the second cuff arm including pivoting the second cuff arm about a pivot connection between the base link and the first end portion of the second cuff arm.

90. A method as set forth in claim 62 wherein the joint and the first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decrease in angle as the joint is extended, said step of moving an actuator member relative to the first and second cuff arms includes moving the actuator member along a portion of a path which is disposed in the outer sector, said step of pivoting the first cuff arm under the influence of force transmitted from the actuator member through the first link being performed with at least a portion of the first link in the outer sector, said step of pivoting the second cuff arm under the influence of force transmitted from the actuator member through the second link being performed with at least a portion of the second link in the outer sector.

91. A method for effecting relative movement between first and second body portions interconnected by a joint, said method comprising the steps of connecting a first cuff and cuff arm with the first body portion, connecting a second cuff and cuff arm with the second body portion, bending the joint by transmitting force through the first and second cuffs to the first and second body portions, moving the first cuff along the first cuff arm during bending of the joint, and moving the second cuff along the second cuff arm during bending of the joint.

92. A method as set forth in claim 91 wherein said step of bending the joint, moving the first cuff along the first cuff arm and moving the second cuff along the second cuff arm include manually moving an input member, transmitting force from the input member to the first and second cuff arms to move the first and second cuff arms relative to each other, and transmitting force from the input member to the first and second cuffs to move the first and second cuffs along the first and second cuff arms.

93. A method as set forth in claim 92 wherein said step of manually moving an input member is performed by a person having the first and second body portions with which the first and second cuffs are connected.

94. A method as set forth in claim 93 further including the step of limiting the force transmitted to the first and second cuff arms from the input member to a predetermined maximum force.

95. A method as set forth in claim 91 further including the step of moving an actuator member relative to the first and second cuff arms, said step of bending the joint includes pivoting the first cuff arm under the influence of force transmitted through a first force transmitting member during movement of the actuator member and pivoting the second cuff arm under the influence of force transmitted through a second force transmitting member during movement of the actuator member, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm under the influence of force transmitted from the actuator member through the first force transmitting member, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm under the influence of force transmitted from the actuator member through the second force transmitting member.

96. A method as set forth in claim 91 wherein said step of bending the joint includes pivoting the first and second cuff arms about axes which are offset from a central portion of the joint.

97. A method as set forth in claim 91 wherein said step of bending the joint includes bending the joint in extension, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction toward the joint, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction toward the joint.

98. A method as set forth in claim 97 wherein said step of bending the joint in extension includes subjecting the joint to a limited amount of distraction.

99. A method as set forth in claim 91 wherein said step of bending the joint includes bending the joint in flexion, said step of moving the first cuff along the first cuff arm includes moving the first cuff along the first cuff arm in a direction away from the joint, said step of moving the second cuff along the second cuff arm includes moving the second cuff along the second cuff arm in a direction toward the joint.

100. A method as set forth in claim 99 wherein said step of bending the joint in flexion includes subjecting the joint to a limited amount of distraction.

101. A method as set forth in claim 91 further including the step of providing an indication of the degree of flexion of the joint during performance of said step of bending the joint.

102. A method as set forth in claim 91 further including the step of adjusting an angle between one of the cuff arms and the one of the cuffs attached thereto by rotating the one cuff attached to the one cuff arm about a connection between the one cuff and the one cuff arm.

103. A method as set forth in claim 91 further including the steps of manually moving a member to effect the transmittal of force from the member through a linkage to the first and second cuff arms, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting force transmitted through the linkage to the first and second cuff arms and from the first and second cuff arms to the first and second cuffs, said step of moving the first cuff along the first cuff arm includes transmitting force from the member through the linkage to the first cuff, said step of moving the second cuff along the second cuff arm includes transmitting force from the member through the linkage to the second cuff.

104. A method as set forth in claim 103 wherein said step of manually moving a member is performed by a person having the first and second body portions with which the first and second cuffs are connected.

105. A method as set forth in claim 91 further including the step of operating a motor to effect the transmittal of force from the motor to the first and second cuff arms, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting the force transmitted from the motor to the first and second cuff arms to the first and second cuffs, said step of moving the first cuff along the first cuff arm includes transmitting force from the motor to the first cuff, said step of moving the second cuff along the second cuff arm includes transmitting force from the motor to the second cuff.

106. A method as set forth in claim 91 Wherein said step of bending the joint includes providing relative movement between the first and second cuffs to bend the joint in one direction, allowing body tissue to stretch by retaining the cuffs against movement relative to each other after having performed said step of providing relative movement between the first and second cuffs, and, thereafter, providing additional relative movement between the first and second cuffs to further bend the joint in the one direction.

107. A method as set forth in claim 91 wherein said step of bending the joint includes bending the joint to one end of the joint'"'"'s range of motion, holding the joint against movement from the one end of the joint'"'"'s range of motion for a period of time, and then bending the joint to an end of the joint'"'"'s range of motion opposite to the one end.

108. A method as set forth in claim 91 further including the step of operating a motor to effect the transmittal of force from the motor through first and second links to the first and second cuff arms, said step of moving the first cuff along the first cuff arm includes transmitting force from the motor to the first cuff through the first link, said step of moving the second cuff along the second cuff arm includes transmitting force from the motor to the second cuff through the second link.

109. A method as set forth in claim 91 wherein said steps of connecting a first cuff with the first body portion and connecting the second cuff with the second body portion includes connecting at least one of the cuffs with a pin which projects from a bone in one of the body portions, said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes transmitting force from the one cuff to the pin and transmitting force from the pin to the bone in the one of the body portions.

110. A method as set forth in claim 91 Wherein said step of bending the joint by transmitting force through the first and second cuffs includes transmitting force through a mechanism by operating the mechanism in a first direction to bend the joint, said method further including retaining the joint in a condition to which it is bent with resistance provided by the mechanism to operation in a direction opposite to the first direction by force transmitted from the first and second body portions to the mechanism.

111. A method as set forth in claim 91 wherein said step of bending the joint by transmitting force through the first and second cuffs includes actuating a ratchet drive mechanism in a first direction and retaining the first and second cuffs against relative movement with the ratchet drive mechanism upon interruption of said step of actuating the ratchet drive mechanism.

112. A method as set forth in claim 111 wherein said step of actuating a ratchet drive mechanism is performed by a person having the first and second body portions with which the first and second cuffs are connected.

113. A method as set forth in claim 91 wherein said step of bending the joint includes effecting relative movement between the first and second cuffs in a first direction from a first position relative to each other to a second position relative to each other, interrupting said step of bending the joint for a period of time, and, thereafter, resuming said step of bending the joint by effecting relative movement between the first and second cuffs in the first direction from the second position relative to each other to a third position relative to each other.

114. A method as set forth in claim 91 wherein said step of bending the joint by transmitting force through the first and second cuffs to the first and second body portions includes applying force to a mechanism connected with the first and second cuffs and limiting the force applied to the mechanism to a predetermined maximum force.

115. A method as set forth in claim 114 wherein said step of applying force to a mechanism includes applying torque to the mechanism, said step of limiting the force applied to the mechanism includes limiting the torque applied to the mechanism.

116. A method as set forth in claim 114 wherein said step of applying force to the mechanism includes operating an electric motor to drive the mechanism, said step of limiting the force applied to the mechanism includes limiting the force applied to the mechanism by the electric motor during operation of the electric motor.

117. A method as set forth in claim 114 wherein said step of applying force to a mechanism is performed by a person having the first and second body portions with which the first and second cuffs are connected and includes manually applying force to an input to the mechanism, said step of limiting the force applied to the mechanism includes limiting the force transmitted between the input to the mechanism and the mechanism.

118. A method as set forth in claim 91 wherein said steps of moving the first and second cuffs along the first and second cuff arms includes moving the first cuff along the first cuff arm in a direction toward the joint and moving the second cuff along the second cuff arm in a direction toward the joint simultaneously with movement of the first cuff along the first cuff arm in a direction toward the joint.

119. A method as set forth in claim 118 wherein said steps of moving the first and second cuffs along the first and second cuff arms includes moving the first cuff along the first cuff arm in a direction away from the joint and moving the second cuff along the second cuff arm in a direction away from the joint simultaneously with movement of the first cuff along the first cuff arm in a direction away from the joint.

120. A method as set forth in claim 91 further including the step of manually actuating a linkage to transmit force to effect relative movement between the first and second cuff arms and to simultaneously therewith effect movement of first cuff along the first cuff arm and movement of the second cuff along the second cuff arm.

121. A method as set forth in claim 120 wherein said step of manually actuating a linkage is performed by a person having the first and second body portions with which the first and second cuffs are connected.

122. A method as set forth in claim 120 wherein said step of manually actuating a linkage to transmit force to effect relative movement between the first and second cuff arms includes manually actuating the linkage in a first direction to effect relative movement between the first and second cuff arms to first positions relative to each other, maintaining the first and second cuff arms stationary in the first positions relative to each other for a predetermined length of time, and, thereafter, manually actuating the linkage in the first direction to again effect relative movement between the first and second cuff arms.

123. A method as set forth in claim 91 wherein said step of bending the joint by transmitting force through first and second cuffs to the first and second body portions includes moving an actuator member along a path, transmitting force from the actuator member through a first force transmitting member to the first cuff arm to pivot the first cuff arm in a first direction about a pivot connection between the first cuff arm and a base link as the actuator member moves along the path, and transmitting force from the actuator member through a second force transmitting member to the second cuff arm to pivot the second cuff arm in a second direction about a pivot connection between the second cuff arm and the base link as the actuator member moves along the path, said step of moving the first cuff along the first cuff arm during bending of the joint includes moving the first cuff along the first cuff arm under the influence of force transmitted from the actuator member through the first force transmitting member to the first cuff as the actuator member moves along the path, said step of moving the second cuff along the second cuff arm during bending of the joint includes moving the second cuff along the second cuff arm under the influence of force transmitted from the actuator member through the second force transmitting member to the second cuff as the actuator member moves along the path.

124. A method as set forth in claim 123 wherein said step of moving the actuator member along a path includes moving the actuator member along a path which extends through the joint.

125. A method as set forth in claim 123 wherein said step of moving the actuator member along a path includes effecting relative rotation between internally and externally threaded members to move one of the threaded members connected with the actuator member relative to the other threaded member.

126. A method as set forth in claim 91 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes engaging an outer side surface of the first body portion with an inner side surface of the first cuff, said method further including gripping the first body portion with the first cuff with sufficient force to prevent relative movement between the outer side surface of the first body portion and the inner side surface of the first cuff during performance of said step of moving the first cuff along the first cuff arm, said step of connecting a second cuff and a second cuff arm with the second body portion includes engaging an outer side surface of the second body portion with an inner side surface of the second cuff, said method further including gripping the second body portion with the second cuff with sufficient force to prevent relative movement between the outer side surface of the second body portion and the inner side surface of the second cuff during performance of said step of moving the second cuff along the second cuff arm.

127. A method as set forth in claim 91 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with a first end portion of the first cuff arm adjacent to the joint, said step of connecting a second cuff and a second cuff arm with the second body portion includes connecting the second cuff arm with the second body portion with a first end portion of the second cuff arm adjacent to the joint and spaced from the first end portion of the first cuff arm and with a base link extending between the first end portions of the first and second cuff arms, said step of bending the joint includes pivoting the first cuff arm about a pivot connection between the base link and the first end portion of the first cuff arm and pivoting the second cuff arm about a pivot connection between the base link and the first end portion of the second cuff arm, the pivot connections between the first and second cuff arms and the base link being spaced apart on the base link.

128. A method as set forth in claim 91 wherein the joint and the first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said step of bending the joint includes transmitting force from a location in the outer sector to the first and second cuff arms, said step of moving the first cuff along the first cuff arm includes transmitting force from the location in the outer sector to the first cuff, said step of moving the second cuff along the second cuff arm includes transmitting force from the location in the outer sector to the second cuff.

129. A method as set forth in claim 91 wherein the joint and the first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said step of bending the joint includes pivoting the first cuff arm about a first pivot connection which is disposed in the outer sector and pivoting the second cuff arm about a second pivot connection which is disposed in the outer sector and is spaced from the first pivot connection.

130. A method as set forth in claim 129 wherein said step of connecting the first cuff and the first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with the first cuff arm disposed in the outer sector, said step of connecting the second cuff and the second cuff arm with the second body portion includes connecting the second cuff arm with the second body portion with the second cuff arm disposed in the outer sector.

131. A method as set forth in claim 91 wherein the joint and first and second body portions define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said method further including moving an actuator member in the outer sector, said step of bending the joint includes transmitting force from the actuator member through a first link disposed in the outer sector to the first cuff arm and transmitting force from the actuator member through a second link disposed in the outer sector to the second cuff arm during movement of the actuator member.

132. A method as set forth in claim 131 wherein said step of moving the first cuff along the first cuff arm includes transmitting force from the first link to the first cuff during movement of the actuator member, said step of moving the second cuff along the second cuff arm includes transmitting force from the second link to the second cuff during movement of the actuator member.

133. A method of effecting relative movement between first and second body portions which are interconnected by a joint and which define on one side of the joint an inner sector which decreases in angle as the joint is flexed and define on the opposite side of the joint an outer sector which decreases in angle as the joint is extended, said method comprising the steps of connecting a first cuff and a first cuff arm with the first body portion, connecting a second cuff and a second cuff arm with the second body portion, moving an actuator member along a portion of a path disposed in the outer sector, transmitting force from the actuator member to the first cuff arm through a first force transmitting member disposed in the outer sector during movement of the actuator member along the portion of the path disposed in the outer sector, transmitting force from the actuator member to the second cuff arm through a second force transmitting member during movement of the actuator member along the portion of the path disposed in the outer sector and bending the joint under the influence of force transmitted from the actuator member to the first and second cuff arms through the first and second force transmitting members during movement of the actuator member along the portion of the path disposed in the outer sector.

134. A method as set forth in claim 133 further including the steps of moving the first cuff along the first cuff arm under the influence of force transmitted to the first cuff through the first force transmitting member during movement of the actuator member along the portion of the path disposed in the outer sector, and moving the second cuff along the second cuff arm under the influence of force transmitted to the second cuff through the second force transmitting member during movement of the actuator member along the portion of the path disposed in the outer sector.

135. A method as set forth in claim 133 wherein said step of moving the actuator member along the portion of the path disposed in the outer sector includes manually moving an input member disposed in the outer sector and moving the actuator member under the influence of force transmitted to the actuator member from the input member during manual movement of the input member.

136. A method as set forth in claim 135 wherein said step of manually moving the input member is performed by a person having the first and second body portions with which the first and second cuffs are connected.

137. A method as set forth in claim 133 wherein said step of moving the actuator member along the portion of the path disposed in the outer sector includes operating a motor disposed in the outer sector and moving the actuator member under the influence of force transmitted from the motor to the actuator member during operation of the motor.

138. A method as set forth in claim 133 wherein said step of connecting a first cuff and a first cuff arm with the first body portion includes connecting the first cuff arm with the first body portion with a first end portion of the first cuff arm adjacent to the joint, said step of connecting a second cuff and a second cuff arm with the second body portion includes connecting the second cuff with the second body portion with a first end portion of the second cuff arm adjacent to the joint and spaced from the first end portion of the first cuff arm and with a base link extending between the first end portions of the first and second cuff arms, said step of bending the joint includes pivoting the first cuff arm about a pivot connection between the base link and the first end portion of the first cuff arm under the influence of force transmitted to the first cuff arm from the actuator member through the first force transmitting member during movement of the actuator member along the portion of the path disposed in the outer sector and pivoting the second cuff arm about a pivot connection between the base link and the first end portion of the second cuff arm under the influence of force transmitted to the second cuff arm from the actuator member through the second force transmitting member during movement of the actuator member along the portion of the path disposed in the outer sector.

139. A method as set forth in claim 133 wherein said step of moving an actuator member along a portion of a path disposed in the outer sector includes effecting relative rotation between internally and externally threaded members to move one of the threaded members and the actuator member relative to the other threaded member.

140. A method as set forth in claim 133 wherein said step of bending the joint includes bending the joint in extension, said method further including the steps of moving the first cuff along the first cuff arm in a direction toward the joint during bending of the joint and moving the second cuff along the second cuff arm in a direction toward the joint during bending of the joint.

141. A method as set forth in claim 140 wherein said step of bending the joint in extension includes subjecting the joint to a limited amount of distraction.

142. A method as set forth in claim 133 wherein said step of bending the joint includes bending the joint in flexion, said method further including the steps of moving the first cuff along the first cuff arm in a direction away from the joint during bending of the Joint and moving the second cuff along the second cuff arm in a direction away from the joint during bending of the joint.

143. A method as set forth in claim 142 wherein said step of bending the joint in flexion includes subjecting the joint to a limited amount of distraction.

144. A method as set forth in claim 133 further including the step of providing an indication of the degree of flexion of the joint during performance of said step of bending the joint.

145. A method as set forth in claim 133 wherein said step of bending the joint includes pivoting the first cuff arm in a first direction and pivoting the second cuff arm in a second direction which is opposite to the first direction, allowing body tissue to stretch by retaining the first and second cuff arms against pivotal movement after having performed said steps of pivoting the first cuff arm in a first direction and pivoting the second cuff arm in a second direction, and, thereafter, pivoting the first cuff arm in the first direction and pivoting the second cuff arm in the second direction.

146. A method as set forth in claim 133 wherein said step of bending the joint includes bending the joint to one end of the joint'"'"'s range of motion, holding the joint against movement from the one end of the joint'"'"'s range of motion for a period of time, and then bending the joint to an end of the joint'"'"'s range of motion opposite to the one end.

147. A method as set forth in claim 133 wherein said steps of moving an actuator member includes operating a mechanism to move the actuator member in a first direction to bend the joint, said method further including retaining the joint in a condition to which it is bent by resisting movement of the actuator member in a direction opposite to the first direction with resistance provided by the mechanism.

148. A method as set forth in claim 133 wherein said step of moving the actuator member includes moving the actuator member in a first direction from a first position to a second position, interrupting said step of moving the actuator member in a first direction for a period of time upon movement of the actuator member to the second position, and, thereafter, moving the actuator member in the first direction from the second position, said step of bending the joint includes bending the joint in one direction from a first condition to a second condition during movement of the actuator member in the first direction from the first position to the second position, interrupting said step of bending the joint during interruption of said step of moving the actuator member in the first direction, and, thereafter, bending the joint in the one direction from the second condition toward a third condition during movement of the actuator member in the first direction from the second position.