Anterior support device for the lower limbs

Abstract

The invention relates to the field of ergonomic furniture. The device (1) comprises an upper support element (8) for supporting the thighs and a lower support element (9) for supporting the legs or tibias, that can be separated by an open space (11) or recess for the knees. An assembly (7) formed by the two support elements (8, 9) is mounted so that it pivots around a horizontal axis (A) on a bearing structure (2, 6), wherein rotation of the assembly (7) enables the support elements (8, 9) to accompany the lower limbs of a user during a transition from one use position to another. The device (1) is incorporated into an apparatus for maintaining a standing or sitting-standing position, having at least one footrest (4, 5). The device is applicable to the arrangement of a workstation, such as a computer workstation or an industrial workstation.

Claims

1. An anterior support device for supporting lower limbs of a user during a standing position and enabling the user to change positions; said device comprising: an upper support element for supporting a front of thighs, substantially extending in a transverse plane, a lower support element for supporting a front of legs or tibias, substantially extending in a transverse plane, at least one open space or recess between the upper support element and the lower support element to accommodate the user's knees, the upper support element and the lower support element being connected by two lateral risers, wherein an assembly formed by the upper support element and the lower support element is mounted so that it pivots on a bearing structure around a transversely oriented horizontal pivot axis situated near the open space or recess present between the upper support element and the lower support element; and wherein rotation of said assembly around the horizontal pivot axis enables the upper support element and the lower support element to accompany the lower limbs of the user during the user's transition from one use position to another use position.

2. The anterior support device according to claim 1, wherein an obtuse angle is formed between the plane of the upper support element and the plane of the lower support element, said obtuse angle having a fixed value or an adjustable value.

3. The anterior support device according to claim 2, wherein the obtuse angle, formed between the plane of the upper support element and the plane of the lower support element, has a value between 130 and 150.

4. The anterior support device according to claim 2, wherein the apex of the obtuse angle, formed between the plane of the upper support element and the plane of the lower support element, is situated in front of the horizontal pivot axis.

5. The anterior support device according to claim 1, wherein in said assembly the lower support element is pivotally mounted, between the two lateral risers, around an additional transversely oriented horizontal pivot axis situated at an intermediate height of said lower support element, and wherein, when the user transits from one use position to another use position, rotation of the lower support element around the additional transversely oriented horizontal pivot axis relative to the upper support element, in combination with rotation of said assembly around its own horizontal pivot axis, enables the upper support element and the lower support element to accompany the lower limbs of the user.

6. The anterior support device according to claim 1, wherein the lateral risers are elbowed or bent in their median zone near said open space.

7. The anterior support device according to claim 1, comprising one or more stops capable of limiting a pivoting movement of the assembly formed by the upper support element and the lower support element.

8. The anterior support device according to claim 1, comprising a return means capable of pivotally moving the assembly formed by the upper support element and the lower support element, back to an intermediate or neutral position, the intermediate or neutral position being a position in which said assembly is substantially located in a vertical plane.

9. The anterior support device according to claim 1, wherein the assembly formed by the upper support element and the lower support element is pivotally mounted on a movable bearing structure, said movable bearing structure including a pivoting structure having at least one articulation along a transversely oriented horizontal axis.

10. The anterior support device according to claim 1, wherein the upper support element and the lower support element are made of at least one of a semi-rigid material and a flexible or deformable material; wherein the flexible or deformable material is configured in a manner of webbing or straps.

11. The anterior support device according to claim 1, wherein one or both of the upper support element and the lower support element are adapted to support corresponding portions of both of left lower limb and right lower limb of the user.

12. The anterior support device according to claim 1, wherein one or both of the upper support element and the lower support element have a separate left portion and right portion, respectively to support corresponding portions of left lower limb and right lower limb of the user.

13. An apparatus for supporting body of a user in a standing position, said apparatus comprising: an anterior support device for lower limbs, comprising an upper support element for supporting a front of thighs; a lower support element for supporting a front of legs or tibias, the upper support element and the lower support element being connected by two lateral risers; and a bearing structure having a base equipped with at least one footrest; wherein an assembly formed by the upper support element and the lower support element is mounted so that it pivots on the bearing structure around a transversely oriented horizontal pivot axis situated near an open space or recess existing between the upper support element and the lower support element.

14. The apparatus according to claim 13, wherein the assembly formed by the upper support element and the lower support element of the anterior support device for the lower limbs is pivotally mounted between two lateral support legs rising above said base.

15. The apparatus according to claim 14, wherein the assembly formed by the upper support element and the lower support element of the anterior support device for the lower limbs is pivotally mounted around its horizontal pivot axis by means of two lateral pivots, each of which connects an upper part of one of said lateral support legs to a median zone of one of said lateral risers, near said open space.

16. The apparatus according to claim 13, wherein said at least one footrest has at least one portion having a slope associated with at least one use position.

17. The apparatus according to claim 13, comprising at least one of an anterior support element and a posterior support element for supporting a torso of the user.

18. The apparatus according to claim 17, wherein the posterior support element for supporting the user's torso is suspended from an upper portion of the assembly formed by the upper support element and the lower support element of the anterior support device for the lower limbs.

19. The apparatus according to claim 17, wherein the anterior support element for supporting the user's torso is borne by the assembly formed by the upper support element and the lower support element of the anterior support device for the lower limbs, and wherein said anterior support element is located in an upward extension of the upper support element for the thighs.

20. The apparatus according to claim 13, wherein in said assembly the lower support element is pivotally mounted, between the two lateral risers, around an additional transversely oriented horizontal pivot axis situated at an intermediate height of said lower support element.

21. The apparatus according to claim 13, wherein one or both of the upper support element and the lower support element are adapted to support corresponding portions of both of left lower limb and right lower limb of the user.

22. The apparatus according to claim 13, wherein the assembly formed by the upper support element and the lower support element of the anterior support device for the lower limbs is mounted on a center support column rising above a base having the at least one footrest, wherein said assembly is pivotally mounted around a vertical axis of the center support column.

23. The apparatus according to claim 13, wherein the at least one footrest includes an anterior footrest and a posterior footrest, the anterior footrest and the posterior footrest having opposite slopes, wherein the anterior footrest and the posterior footrest are respectively associated with two different use positions.

24. The apparatus according to claim 13, wherein one or both of the upper support element and the lower support element have a separate left portion and right portion, respectively adapted to support corresponding portions of left lower limb and right lower limb of the user.

25. The apparatus according to claim 13, wherein the apparatus is adapted for use in association with any of a desk and a workstation, the workstation being any of a computer workstation and an industrial workstation; and wherein the apparatus, in a first use position, supports the user in a forward leaning standing position, and in a second use position, supports the user in a backward leaning standing position, or an upright standing position.

26. The apparatus according to claim 13, comprising one or more stops capable of limiting a pivoting movement of the assembly formed by the upper support element and the lower support element.

27. The apparatus according to claim 13, comprising a return means capable of pivotally moving the assembly formed by the upper support element and the lower support element, back to an intermediate or neutral position, the intermediate or neutral position being a position in which said assembly is substantially located in a vertical plane.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) A better understanding of the invention will be obtained, and other characteristics and advantages made clear, from the following description, which refers to the schematic drawings attached, representing, by way of example, several embodiments of this anterior support device for the lower limbs and the body support assembly equipped with such a support device.

(2) In these drawings:

(3) FIG. 1 is a perspective view of an anterior support device according to the invention, in a first embodiment.

(4) FIG. 2 is a plan view from above of the device of FIG. 1.

(5) FIG. 3 is a side view of the device in intermediate or neutral position.

(6) FIG. 4 is a schematic view illustrating the use of the device of the above figures in a first use position.

(7) FIG. 5 is a schematic view similar to FIG. 4 but illustrating a second use position of the same device.

(8) FIG. 6, a perspective view, represents a variant of the device in the preceding figures.

(9) FIG. 7 is a side view of an anterior support device according to the invention, in a second embodiment.

(10) FIGS. 8 and 9 are schematic views illustrating the operation and use of the device of FIG. 7 in two distinct positions.

(11) FIG. 10 is a side view of an anterior support device according to the invention, in a third embodiment.

(12) FIG. 11 is an enlarged detail of FIG. 10.

(13) FIG. 12 is a perspective view of an anterior support device according to the invention, in a fourth embodiment.

(14) FIGS. 13 and 14 are schematic views illustrating the operation and use of the device of FIG. 12 in two distinct positions.

DETAILED DESCRIPTION

(15) We first refer to FIGS. 1 to 5 relative to a first embodiment.

(16) The anterior support device for the lower limbs, referred to overall as 1, is part of a complete apparatus for maintaining the body in a standing or sitting-standing position.

(17) This apparatus comprises a base 2, of generally rectangular shape in the example shown. Base 2 is here provided with four rollers 3 for movement on the floor, rollers 3 being however optional. This base 2 is equipped with a dual footrest, with anterior footrest 4, here consisting of two inclined platforms 4a and 4b, respectively left and right, and posterior footrest 5, here consisting of two other platforms 5a and 5b, respectively left and right, whose inclination to the horizontal is opposite and greater than that of platforms 4a and 4b. The separation between the two platforms 4a and 4b of anterior footrest 4 can be adjustable, as can the separation of the two platforms 5a and 5b of posterior footrest 5. Intermediate horizontal platforms (not shown) can connect platforms 4a and 4b of anterior footrest 4 to corresponding platforms 5a and 5b of posterior footrest 5.

(18) Above base 2, between anterior footrest 4 and posterior footrest 5, two lateral support legs 6 rise, respectively left and right, each lateral support leg 6 having a telescopic tubular structure.

(19) Anterior support device 1 comprises movable assembly 7, essentially formed by upper support element 8 for the thighs and lower support element 9 for the legs, assembly 7, thus constituted, being pivotally mounted around horizontal axis A, transversely oriented, according to arrow F1, between the two lateral support legs 6.

(20) More specifically, upper support element 8 and lower support element 9 are connected by means of a frame or by two lateral risers 10, which maintain them at a distance from one another, so that open space 11 is found between upper support element 8 and lower support element 9. Upper support element 8 substantially extends in a first transverse plane P1, and lower support element 9 substantially extends in another transverse plane P2. Lateral risers 10 are elbowed or bent in their median zone, thus, near open space 11, such that the two planes P1 and P2 together form an obtuse angle B, the value of this angle being advantageously comprised between 130 et 150.

(21) Assembly 7, formed by upper support element 8 and lower support element 9, is pivotally mounted around horizontal axis A by means of two lateral pivots 12, each of which connects the upper part of lateral support leg 6 to the median zone of lateral riser 10, near open space 11. Stops (not shown), which can be incorporated in the two lateral pivots 12, are provided to limit the pivoting of assembly 7 in both directions of rotation and, thus, define the extreme angular positions of this assembly 7, as specified below.

(22) Upper support element 8 and lower support element 9 can be made of a flexible or deformable material, preferably inextensible, similar to webbing or straps, respectively stretched between the upper and lower portions of the two lateral risers 10.

(23) The apparatus also comprises additional support element 13 for the user's torso, which is here a posterior support element connected and, in particular, suspended from assembly 7. As shown in FIG. 3, additional support element 13, a type of webbing or strap and preferably of an elastic material, connects the respective upper portions of the two lateral risers 10, with the possibility of unhooking at least one side to allow access. Depending on the height, such an additional support element 13 can serve to position and support the user's upper thighs or buttocks, or even the lumbar region.

(24) In a manner not shown, and also with respect to a posterior support element, this additional support element 13 can be separate from anterior support device 1 and be borne by a separate support structure, stationary or movable, the assembly forming a complete apparatus. If it consists of a stationary support structure, this is connected to base 2 or directly attached to the floor. If it consists, on the other hand, of a movable support structure, this is advantageously mounted on rollers so that additional support element 13 can easily be brought closer or further away from anterior support device 1.

(25) FIGS. 4 and 5 illustrate the use of anterior support device 1 described above, whose operation is based on the pivoting of assembly 7 around horizontal axis A, between two extreme angular positions.

(26) In a first extreme position (FIG. 4), the user is leaning forward and presses his thighs against upright upper support element 8 and his legs against lower support element 9, obliquely directed toward the back, while his two feet press upon posterior footrest 5.

(27) In a second extreme position (FIG. 5), the user is leaning backward and presses his thighs against upper support element 8, obliquely directed toward the back, and his legs against upright lower support element 9, while his two feet press upon anterior footrest 4.

(28) The transition from one extreme position to another, therefore, from a first use position to a second use position, is carried out by rotating assembly 7 around horizontal axis A, along an angle of rotation that can be comprised between 20 and 45, and, more specifically, an angle of rotation comprised between 25 and 35, while moving through the intermediate position of FIG. 3, rotation of assembly 7 thereby accompanying the movement of the user's lower limbs. This movement, notably causing the user's feet to move from one footrest, 4 or 5, to the other, is carried out by alternatively shifting one lower limb and then the other. The stops mentioned above, which can be continuously or discontinuously adjustable, can be used to establish the two extreme positions and their angular spacing.

(29) The intermediate position illustrated in FIG. 3, which can also be referred to as a neutral position, allows the user to easily access the apparatus from the left or right side, in particular, without being inconvenienced by lower support element 9 or by the lower portions of lateral risers 10.

(30) The telescopic structure of the two lateral support legs 6 can be used to adjust the height of horizontal axis A and, consequently, of assembly 7, in line with arrow F2, in particular, to adjust the apparatus to the user's size and, if appropriate, to the environment, in particular, to accommodate the presence of a desk in front of the apparatus.

(31) Optional rollers 3 facilitate the movement of the apparatus over the floor, in particular, in the forward-back direction; these rollers 3 are advantageously self-locking to ensure the stability of the apparatus, especially when transitioning from one use position to another.

(32) A variant of anterior support device 1 is shown in FIG. 6.

(33) Base 2 here has an H configuration while a center support column 14, of telescopic structure, rises above center bar 15 of this base 2. Assembly 7, formed by upper support element 8 and lower support element 9, is pivotally mounted around a horizontal axis A, transversely oriented, by means of single center pivot 16, located at the top of support column 14.

(34) Here, assembly 7 also has two lateral risers 10 as well as a double center separation bar 17, these being connected by transverse bars or arches 18. Upper support element 8 is held between the upper parts of the two lateral risers 10 and comes into contact with the upper portion of double center separation bar 17. Similarly, lower support element 9 is held between the lower parts of the two lateral risers 10 and comes into contact with the lower portion of double center separation bar 17. In this way, upper support element 8 is separated into two portions, respectively left portion 8a and right portion 8b, and, similarly, lower support element 9 is separated into two portions, respectively left portion 9a and right portion 9b, left portion 8a or 9a and right portion 8b or 9b having a certain independence, preventing the knees from slipping toward one another.

(35) In the case of this variant, assembly 7 with support elements 8 and 9 can also be pivotally mounted around vertical axis C of support column 14, as suggested by arrow F3.

(36) Center pivot 16 can have a yoke that serves as a stop limiting, on the one hand, the extent to which assembly 7 pivots around horizontal axis A and, on the other hand, the extent to which the same assembly 7 pivots around vertical axis C.

(37) The specific advantages of this first embodiment and, where applicable, its variant according to FIG. 6, are:

(38) sturdy construction,

(39) the fluidity of the transition from one use position to another,

(40) the self-balancing of assembly 7 formed by upper support element 8 and lower support element 9, to the extent that the horizontal pivot axis A of this assembly 7 is substantially located at the midpoint of said assembly,

(41) if assembly 7, formed by upper support element 8 and lower support element 9, is pivotally mounted between two lateral support legs 6, the center open space appearing between these support legs 6, in particular near the user's torso, facilitates the transition from one use position to another,

(42) where applicable, the possibility of additional pivoting of said assembly 7 around vertical axis C, to the extent that this assembly 7 is mounted on center support column 14, which gives the user the ability to advance one knee and draw back the other knee, thereby enabling the user to more easily turn toward one side or the other by a rotational movement of the torso.

(43) We refer now to FIGS. 7 to 9, relative to a second embodiment, wherein the elements shared with the first embodiment and, in particular, assembly 7 and its components or parts, are designated by the same identifying numbers and are not described again. In this other embodiment, the bearing structure that supports assembly 7 is a movable structure, in this case center a support arm 19 pivotally mounted on base 2 in such a way that it can move in an anteroposterior vertical plane.

(44) More specifically, the lower extremity of support arm 19 is pivotally mounted on base 2 by means of a yoke 20, which defines horizontal pivot axis P, transversely oriented. At the upper extremity of support arm 19, assembly 7, formed by upper support element 8 for the thighs and lower support element 9 for the legs, is pivotally mounted along horizontal axis A.

(45) Operation of this embodiment is determined by the pivoting of support arm 19, according to double arrow F4, between two extreme angular positions that can be determined by stationary or adjustable stops (not shown), combined with the pivoting of assembly 7 around horizontal axis A.

(46) In a first extreme position (FIG. 8), the user leans forward while support arm 19 is inclined backward, forming an angle, alpha, with the vertical. As in the first embodiment, the user presses his thighs against upper support element 8, which is almost vertical, and his legs against lower support element 9, obliquely directed backward, such that his two feet press upon posterior footrest 5.

(47) In a second extreme position (FIG. 9), the user is leaning backward while support arm 19 is, conversely, inclined frontward. As in the first embodiment, the user presses his thighs against upper support element 8, which is directed obliquely toward the rear, and his legs against lower support element 9, which is upright, such that his two feet press upon the anterior footrest 4.

(48) During the transition from one use position to the other, assembly 7 follows the movement of the user's lower limbs. If necessary, the pivoting of assembly 7 and support arm 19 along horizontal axes A and P, respectively, is coordinated by the action of at least one spring or by mechanical means.

(49) The specific advantages of this second embodiment are:

(50) its simplicity of construction, notably with respect to the number of components,

(51) its compactness, with a reduction in size in the anteroposterior direction as well as in the transverse direction,

(52) the fact that the upper portion of the device occupies a substantially invariable position in space, which maintains the user's center of gravity in a substantially constant position and also places the user's torso at a horizontal distance from the work surface that is practically constant for all postures.

(53) FIG. 10 illustrates a third embodiment, distinguished from the previous embodiments by the configuration of footrest 21, which is here single. Footrest 21 has a dual slope in the sense that it has an anterior portion 21a with a smaller angle, for example, comprised between 5 and 15, and a posterior portion 21b, with a greater angle, for example, comprised between 30 and 50. The two portions, 21a and 21b, can be connected by a transitional portion (not shown) with an intermediate slope, of 25 for example, or with a curved profile.

(54) Operation of this embodiment is still based on the pivoting of assembly 7 around horizontal axis A, between two extreme positions. In a first extreme position, the user is leaning forward, with his lower limbs pressed against upper and lower support elements 8 and 9, while the user's feet press against posterior portion 21b of footrest 21. In a second extreme position, the user is leaning backward, with the user's lower limbs still pressed against upper and lower support elements 8 and 9, while the user's feet press against anterior portion 21a of footrest 21.

(55) The position of footrest 21 is advantageously adjustable in the anteroposterior direction, as shown by arrow F5, to adapt footrest 21 to user's size in a manner that is coordinated with the height adjustment of support column 14 and, consequently, of horizontal axis A, in the direction of arrow F2. As a supplement or alternative, footrest 21 can itself be mounted so that it oscillates around another transversely oriented horizontal axis (not shown) in such a way that the slopes of the various portions of this footrest vary.

(56) As also shown in FIG. 10, the apparatus can have additional support element 22 for the user's torso, which is here an anterior support element placed above upper support element 8 for the thighs. In particular, this additional support element 22 is borne by a support frame 23, possibly removable, which is located in the upward extension of the two lateral risers 10. Additional support element 22 can be height adjustable, for example, through the telescoping action of support frame 23, as indicated by arrow F6, to better accommodate the user's size and morphology. Support frame 23 can, in its upper portion, carry additional lateral support elements (not shown) for the elbows or forearms, these latter support elements also benefiting from the height adjustability obtained by the telescoping action of support frame 23.

(57) The specific advantages of this third embodiment are:

(58) finer adjustment according to the length of the user's legs, pressed against the lower support element, through the longitudinally adjustable dual- or triple-slope footrest,

(59) improved comfort for the user's feet, whichever of the two portions, respectively anterior and posterior, of the footrest, they press against,

(60) in the case of the presence of an additional support element for the user's torso, preferably height adjustable, a better distribution of the support points for the user's body, especially when leaning forward.

(61) Out of a concern for simplicity, in the previous figures the apex of obtuse angle B, formed by planes P1 and P2, has been shown as coincident with horizontal pivot axis A of assembly 7.

(62) However, as shown in FIG. 11, the apex of obtuse angle B, formed by planes P1 and P2, is advantageously positioned in front of horizontal axis A, along offset D, obtained by connector arm 24, wherein offset D can be comprised between 5 cm and 30 cm.

(63) Because of this arrangement, the trajectory of assembly 7 can be modified and improved, in particular, to optimize the transition between the two extreme positions of this assembly 7 and corresponding user postures.

(64) FIG. 12 illustrates a fourth embodiment, distinguished from the previous embodiments by the construction of the assembly 7.

(65) The assembly 7 comprises a frame including two lateral risers 10 which are pivotally mounted around a first horizontal axis A, transversely oriented, between the two lateral support legs 6, according to arrow F1. The upper support element 8 is directly attached to the two lateral risers 10. The lower support element 9 is mounted between the two lateral risers 10 so that it pivots around an additional horizontal axis D, transversely oriented and parallel to first horizontal axis A.

(66) More particularly, the lower support element 9 has separate left portion 9a and right portion 9b, each pivotally mounted around additional horizontal axis D, as suggested by arrows F7 and F8. The additional horizontal pivot axis D is situated at an intermediate height of left portion 9a and right portion 9b of lower support element 9.

(67) In this embodiment, the base 2 is equipped with a posterior footrest 5, consisting of a single inclined platform or of two inclined platforms 5a and 5b, respectively left and right. The remaining portion of base 2 is forming a horizontal platform.

(68) FIGS. 13 and 14 illustrate the use of the anterior support device of FIG. 12, the operation of which is based on the pivoting of the whole assembly 7 around first horizontal axis A, as described above, and further on the simultaneous pivoting of the lower support element 9 around additional horizontal axis D.

(69) The first extreme position (FIG. 13) is a forward leaning position. The upper support element 8 is obliquely directed toward the front, forming a small angle with the vertical plane. The lower support element 9 is obliquely directed, substantially perpendicular to the inclined platform(s) of posterior footrest 5. The user is leaning forward and presses his thighs against upper support element 8 and his legs against lower support element 9, while his two feet press upon footrest 5.

(70) The second extreme position (FIG. 14) is an upright standing position. Both support elements 8 and 9 are substantially parallel and vertically oriented. The user is standing upright on the horizontal platform of base 2 and can press his thighs against upper support element 8 and his legs against lower support element 9.

(71) During user's transition from one extreme position to the other extreme position, for example from the forward leaning position to the upright standing position, the whole assembly 7 is pivoting along first horizontal axis A, and simultaneously left portion 9a and right portion 9b of lower support element 9 are pivoting independently from each other along additional horizontal axis D, so as to follow the movement of the user's lower limbs. During this transition, the angle formed between the upper support element 8 and the lower support element 9, and thus between the user's thighs and legs, will vary within a certain range.

(72) Stops 25 and 26 are provided to limit the pivoting of assembly 7 in both directions of rotation and, thus, define the extreme angular positions of this assembly 7. The stops 25 and 26 may be continuously or discontinuously adjustable and can be used to establish the two extreme positions and their angular spacing. Advantageously, this device also has return means, such as a spring 27, capable of returning the assembly formed by the two support elements, respectively upper and lower, by pivoting to an intermediate or neutral position, in particular, to a position in which the assembly is approximately located in a vertical plane.

(73) The specific advantages of this fourth embodiment are:

(74) improved accompanying of the user's lower limbs during the transition from one use position to another,

(75) optimal adaptability to an upright standing position of user,

(76) enhanced lateral access for the user in the upright standing position.

(77) In practical use, anterior support device 1 and the complete apparatus described above can be combined with a desk, in particular, a desk suitable for working while standing, the desk height preferably being adjustable, or combined with a specialized workstation, such as a computer or industrial workstation. The first use position provided by the device is a standing or sitting-standing position for work, leaning forward, while the second use position provided by the device is a standing or sitting-standing position for work or relaxation, leaning backward or upright standing position, the device facilitating the transition from one use position to the other while accompanying the movement of the user's lower limbs.

(78) As shown by the above, the invention is not limited solely to embodiments of this anterior support device and body support apparatus described above as examples; on the contrary, it encompasses all the variant embodiments and applications covered by the attached claims. Thus, in particular, one would remain within the framework of the invention:

(79) by differently combining the diverse characteristics illustrated, for example, by including two pivoting lateral support arms in the second embodiment;

(80) by modifying the shape and construction of the support elements;

(81) by providing, in place of the open space arranged between the upper support element and the lower support element, one or more recesses or openings capable of accommodating the user's knees;

(82) by eliminating any open space or recess between the upper support element and the lower support element, in which case both support elements are directly connected and can be realized in one piece;

(83) by articulating the assembly formed by the upper support element and

(84) the lower support element around a horizontally pivoting axis placed differently, in particular, an axis located at an intermediate height of the upper support element or near the apex of this upper support element;

(85) by shifting the lateral support legs of the first embodiment to the front or back;

(86) starting from the second embodiment, by providing a different type of movement, that is, in translation rather than in rotation, for the movable bearing structure on which is pivotally mounted the assembly formed by the upper and lower support elements;

(87) more generally, by providing any shape or construction to said bearing structure, whether it is stationary or movable;

(88) starting from the fourth embodiment, by mounting the upper support element, instead of or in addition to the lower support element, around an additional horizontal pivot axis;

(89) by giving the footrest platforms any suitable shape, for example, by combining the left and right platforms to form a single platform extending throughout the width of the base, and by forming those platforms using any process, especially by molding them directly with the base;

(90) by providing, beneath this base, a different number of rollers or by realizing a base without rollers;

(91) by providing other additional support elements, such as elements for the elbows or forearms, or even for the back, similar to a seat back, wherein these additional support elements can be supported by any means, in particular, by lateral support legs that can be extended upward;

(92) by adding various accessories capable of improving the use of the device, in particular, handgrips enabling the user to hold on when entering the device or adjusting its height, or even a step or footwell facilitating user access to the footrest(s);

(93) by realizing the pivot limit stop or stops in any shape and by any means, for example, by simple contact with the edge of a desk or other work surface;

(94) by replacing the pivot or pivots by any means for equivalently realizing a rotational guide, for example, curved tracks that cooperate with pulleys;

(95) by designing the bearing structure not as an autonomous structure resting on the floor but as a structure integrated with a desk or other workstation.