PASSIVE DEVICE FOR ASSISTING USER MOVEMENT

Abstract

TITLE OF THE INVENTION: PASSIVE DEVICE FOR ASSISTING A USER'S MOVEMENT The passive physical assistance device for applying a restoring force to a part of a user's body comprises: - at least one first strap (25) configured to be attached to that part of the user's body, - at least one second strap (28, 29), and - a housing (24) comprising a first plate (41) mechanically linked to each first strap and a second plate (34) mechanically linked to each second strap, and, between these mechanical plates, at least one flexible blade or rod (37, 38), the elastic deformation of which varies according to the spacing between the plates. Figure for the abstract: Figure 4

Description

Title of the invention: PASSIVE DEVICE FOR ASSISTING USER MOVEMENT Technical field of the invention

[0001] The present invention relates to a passive device for assisting a user's movements. It is particularly applicable to the field of assisting the movements of a professional, for example, a handler or a worker. It is designed to relieve the strain on individuals performing repetitive movements or subjected to significant exertion.

[0002] The present invention applies, for example, to the field of assistance to persons suffering from spinal pain or back pain, whether at rest or during exertion, or in outpatient therapy. State of the art

[0003] The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section constitutes prior art simply because of its inclusion in this section.

[0004] Arm and back injuries are still present despite the reduction in the weight of the products to be handled. In the construction and agricultural sectors, 80% of workers are affected by musculoskeletal disorders (MSDs); they suffer from back and arm pain, in particular.

[0005] There are mainly two types of exoskeletons designed to relieve stress on the joints and / or muscles of users: the robotic or "active" exoskeleton and the "passive" exoskeleton. The robotic exoskeleton aims to significantly increase the strength of the operator wearing it, but it has the disadvantage of requiring a power source and at least one actuator, which increases the weight of the exoskeleton or, if it is connected to an external power source, limits the user's range of motion.

[0006] The passive exoskeleton aims to reduce the effort required by the operator and does not consume energy. In particular, the passive exoskeleton is part of an approach to reducing the physical strain during repetitive and / or strenuous work while preventing the onset of musculoskeletal disorders (MSDs).

[0007] Known exoskeletons comprise rigid or elastic elements that exert an action parallel to the user's bones and joints. These elements have a bulk and weight that reduce the user's mobility. Summary of the invention

[0008] Instead of being based on a rigid or flexible frame, as in a classic exoskeleton, the passive movement assistance device of the invention behaves like a set of at least one muscle and tendons connecting each such muscle to parts of the body on either side of the user's muscles to be relieved.

[0009] The objective of this passive assistance device is to increase the strength of the user's muscles, particularly when returning the user to a resting position, for example standing.

[0010] The muscle takes the form of a casing containing at least one rod or blade acting as a spring, preferably supplemented by a strap or cord passing through a series of pulleys or smooth bearings, making it possible to reduce the force on this strap or cord for the same deformation of this spring, or to reduce the deformation of this spring for the same force on the straps. This reduces the size of the casing and the discomfort experienced by the user. Brief description of the figures

[0011] Other advantages, purposes and particular features of the invention will become apparent from the following non-limiting description of at least one particular embodiment of the passive movement assistance device that is the subject of the present invention, with reference to the accompanying drawings, in which: [Fig. 1] schematically represents, in rear view, a first embodiment of the passive assistance device that is the subject of the invention. [Fig.2] schematically represents, in side view, a user equipped with the passive assistance device illustrated in [Fig.1] making an effort to lift a load or to stand up, [Fig. 3] schematically represents, in rear view, the contents of a housing of the passive assistance device illustrated in [Fig. 1], in its resting configuration; [Fig. 4] schematically represents, in rear view, the contents of a housing of the passive assistance device illustrated in [Fig. 1], in its energized configuration; [Fig. 5] schematically represents, in rear view, the contents of a housing of a second embodiment of the passive assistance device of the invention, in its resting configuration. [Fig.6] schematically represents, in rear view, the contents of the case illustrated in [Fig.5], in its powered configuration. [Fig.7] schematically represents, in rear view, the contents of a housing of a third embodiment of the passive assistance device of the invention, in a semi-flexed configuration, [Fig.8] schematically represents, in side view, a housing of a fourth embodiment of the passive assistance device that is the subject of the invention, in a semi-flexed configuration, and [Fig.9] represents, schematically and in side view, a user equipped with the passive assistance device illustrated in [Fig.8] making an effort to lift a load or to stand up. Description of the implementation methods

[0012] The present description is given by way of non-limiting grammar, each feature of an embodiment being able to be advantageously combined with any other feature of any other embodiment.

[0013] It should be noted from the outset that the figures are not to scale.

[0014] As will be understood from the present description, various inventive concepts can be implemented by one or more of the methods or devices described below, several examples of which are provided herein. The actions or steps carried out in the implementation of the method or device can be ordered in any appropriate manner. Consequently, it is possible to construct embodiments in which the actions or steps are performed in a different order than that illustrated, which may include the simultaneous execution of certain acts, even if they are presented as sequential acts in the illustrated embodiments.

[0015] The indefinite articles "un" and "une", as used in the description, should be understood as meaning "at least one", unless clearly stated otherwise.

[0016] The expression "and / or", as used in this document, shall be understood as meaning "either or both" of the elements thus joined, that is, elements that are present conjunctively in some cases and disjunctively in others. Multiple elements listed with "and / or" shall be interpreted in the same way, that is, "one or more" of the elements thus joined. Other elements may also be present, other than those specifically identified by the "and / or" clause, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with an open language such as "including", may refer, in one embodiment, to A only (possibly including elements other than B); in another embodiment, to B only (possibly including elements other than A); in yet another embodiment, to A and B (possibly including other elements); etc.

[0017] As used herein in the description, "or" should be understood inclusively.

[0018] As used in this description, the expression "at least one," with reference to a list of one or more elements, should be understood as meaning at least one element chosen from one or more elements in the list of elements, but not necessarily including at least one of each element specifically enumerated in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than the elements specifically identified in the list of elements to which the expression "at least one" refers, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, possibly including more than one, A, without B present (and possibly including elements other than B); in another embodiment, to at least one, possibly including more than one, B, without A present (and possibly including elements other than A); in yet another embodiment, to at least one, possibly including more than one, A, and at least one, possibly including more than one, B (and possibly including other elements); etc.

[0019] In the description below, all transitive expressions such as "comprising", "including", "carrying", "having", "containing", "implying", "holding", "composed of", and others, should be understood as open, that is, as meaning including but not limited to. Only the transitive expressions "consisting of" and "consisting essentially of" should be understood as closed or semi-closed transitive expressions, respectively.

[0020] Throughout this description, "upper" or "top" refers to the area at the top when a user, standing or seated, is wearing the exoskeleton of the invention and shown in the figures, and "lower" or "bottom" refers to the area at the bottom when a user, standing or seated, is wearing the exoskeleton of the invention and shown in these figures. The figures thus represent the normal orientation of the exoskeleton when used by a standing or seated user. The "heights" are derived from these definitions. The "widths" are defined from right to left in Figures 1 and 3 to 7, therefore also from right to left of the user's body. These are the dimensions in the direction from one shoulder of the user to the other.The term "front," "front," "facing," or "ventral" refers to the area on the user's stomach during exoskeleton use, while "back" or "dorsal" refers to the area on the user's back during exoskeleton use. "Internal" or "inner" refers to the area close to or facing the user's torso, while "external" or "outer" refers to the area away from the torso or facing away from it. A "chest harness" is an assembly of straps connected by [unclear - possibly "braces"]. An easily detachable buckle designed to encircle a person's torso. Such a harness may take the form of a chest or thoracic belt made of a single strap. This belt may optionally be supplemented by shoulder straps that pass over the shoulders and / or under the pelvis.

[0021] Throughout the description, the term "strap" is not limited to a wide, flat band, but also covers bands, suspenders, belts, sleeves, straps, belts, ropes or cords and, more generally, elements that are flexible in bending and practically inextensible in length.

[0022] It is noted from the outset that the dimensions of the passive assistance device are adapted to a predetermined user, for example a European man or woman of average build, as defined by statistical studies of this population.

[0023] The passive assistance device that is the subject of the invention aims to combat muscular or skeletal pain and allows for the improvement of working conditions, by reducing the hardship of maintaining a standing, bent, squatting or sitting position, and its physical and mental consequences on its user.

[0024] This passive assistance device is lightweight and intuitive to use. It is particularly suitable for any work requiring bending or flexing a joint. The user retains a wide range of movement and is not hindered in performing tasks that do not require mechanical assistance.

[0025] The figures illustrate an application of the invention to relieve back muscle strain when the user bends forward, particularly when lifting a load. Of course, the present invention also applies to any other type of muscle relief around joints, for example, the shoulder, knee, elbow, hand, or foot.

[0026] Figure 1 shows a passive movement assistance device 20, the subject of the invention. This passive assistance device 20 comprises a chest harness 21, sleeves 22 and 23, each intended to encircle one of the user's legs, and a housing 24. Alternatively (not shown), a single sleeve encircles both of the user's legs. This housing 24 is connected to the chest harness 21 by a central upper strap 25 and by upper lateral straps 26 and 27. The housing 24 is connected to the sleeves 22 and 23 by lower straps 28 and 29, respectively.

[0027] The housing 24 is configured to apply a restoring force between the central upper strap 25 and the lower straps 28 and 29 when they move apart during a movement of the user 30. [Fig.2] schematically illustrates this situation.

[0028] The housing 24 includes at least one deformed blade or rod forming a spring to apply this restoring force. Preferably, this blade or rod is made of composite material.

[0029] In the first embodiment illustrated in [Fig. 3], the central upper strap 25 is fixed to the housing 41 of the casing 24 and is therefore stationary relative to this casing 24. The housing 41 of the casing 24 thus forms a plate mechanically connected to the central upper strap 25. In contrast, the lower straps 28 and 29 are formed from the same strap, which passes through at least one means for changing the direction of the force exerted by the strap. This means also reduces the deformation of the blade or rod for the same displacement of the strap under the effect of the user's movements. This means for changing the direction of the force typically consists of a pulley or a plain bearing, with the strap following a portion of its circumference. By combining such means, a block and tackle is formed.For the sake of clarity, in the following description, the term "pulley" is used generically to refer to any means of changing the direction of the force exerted by a strap.

[0030] In the first embodiment illustrated in [Fig.3], three pulleys 31, 32 and 33 constitute a pulley system.

[0031] At least one pulley, here pulleys 31 and 32, is mounted on a movable plate 34 guided in vertical translation on a slide 35 by means of slides 36. Pulley 33 is fixedly mounted in the housing 24. Two blades or rods 37 and 38 are mounted between the movable plate 34 and the lower part of the housing 24. At the upper end of these blades or rods 37 and 38, pivot joints 39 allow rotation of this end relative to the movable plate 34. At the lower end of these blades or rods 37 and 38, pivot joints 40 allow rotation of this end relative to the housing 24.

[0032] As illustrated in [Fig. 4], when the upper central strap 25 is moved away from the lower straps 28 and 29, the movable plate 34 moves translationally along the slide 35 to approach the lower part of the case 24. In this movement, the flexible blades or rods 37 and 38 bend. They therefore exert a restoring force opposing this relative movement of the straps 25, 28, and 29.

[0033] It is noted that a plurality of pulleys 31, 32 and 33 allows, like a hoist, to reduce, inside the case 24, the amplitude of the relative movement of the moving plate 34 and the housing 41 of the case 24 with respect to the amplitude of the relative movement of the upper straps 25 and lower straps 28 and 29.

[0034] Furthermore, the presence of at least one pulley 31 connecting the lower straps 28 and 29 allows for compensation between the movements of these straps relative to the housing 24. The movement of the moving plate 34 thus depends on the average displacement of the lower straps. When these lower straps 28 and 29 are connected to the user's lower limbs, the user's walking therefore does not cause any force to be applied by the housing 24 on the straps 25, 28 and 29, the straps 28 and 29 simply rotating the pulleys 31 to 33.

[0035] It is noted that, when a plate is stationary relative to the housing, it can be confused with at least part of the housing of this housing, as is the case for the first two embodiments of the device which is the subject of the invention.

[0036] In the second embodiment illustrated in [Fig.5], the central upper strap 25 is fixed to a housing 44 and is therefore immobile relative to this housing 44. The housing 42 of the housing 44 thus forms a plate mechanically linked to the central upper strap 25. In contrast, the lower straps 28 and 29 are formed from the same strap which passes through at least one pulley 51, specifically three pulleys 51, 52 and 53, in the second embodiment.

[0037] At least one pulley, here pulleys 51 and 52, is mounted on a movable plate 54 guided in vertical translation on two slides 55, by means of slides 56. Pulley 53 is fixedly mounted in the housing 44. Two blades or rods 57 and 58 are mounted between the movable plate 54 and the lower part of the housing 44. At the upper end of these blades or rods 57 and 58, pivot joints 59 allow rotation of this end relative to the movable plate 54. At the lower end of these blades or rods 57 and 58, pivot joints 60 allow rotation of this end relative to the housing 44.

[0038] As illustrated in [Fig. 6], when the upper central strap 25 is moved away from the lower straps 28 and 29, the movable plate 54 moves translationally along the slides 55 to approach the lower part of the case 44. In this movement, the flexible blades or rods 57 and 58 bend. They therefore exert a restoring force opposing this relative movement of the straps 25, 28, and 29.

[0039] Again, a plurality of pulleys 51, 52 and 53 allows, like a block and tackle, to reduce, inside the housing 44, the amplitude of the relative movement of the moving plate 54 and the housing 42 of the housing 44, with respect to the amplitude of the relative movement of the upper and lower straps.

[0040] Furthermore, the presence of at least one pulley 51 connecting the lower straps 28 and 29 allows for compensation between the movements of these straps relative to the housing 44. The displacement of the moving plate 54 thus depends on the average displacement of the lower straps. When these lower straps 28 and 29 are connected to the user's lower limbs, the user's gait does not cause therefore no force is applied by the housing 44 on the straps 25, 28 and 29, the straps 28 and 29 simply turning the pulleys 51 to 53.

[0041] Of course, in variants of the first two embodiments, the contents of the case, 24 or 44, are turned upside down, so that the upper strap 25 is connected to the moving plate, 34 or 54, and the lower straps 28 and 29 are fixedly connected to the case, 24 or 44.

[0042] In other variations of the first two embodiments, the number of pulleys is limited to one or increased to an odd number greater than three. The greater this number, the lower the ratio of the relative amplitude of movement of the moving plate, 34 or 54, with respect to the housing, 41 or 42, of the casing, 24 or 44, to the relative amplitude of movement of the central upper strap 25 with respect to the lower straps 28 and 29. Thus, by increasing this number, the dimensions of the casing, 24 or 44, can be reduced, provided that the stiffness of the flexible blades or rods 37 and 38 or 57 and 58 is increased so that the same amplitude of movement of the user corresponds to the same restoring force.

[0043] Figure 7 only partially represents the contents of a housing 64 of a third embodiment. For example, no casing, slide, or slider is shown. In this housing 64, two plates 65 and 66, movable relative to each other, carry pulleys 71 to 73 and 74 to 76, respectively. The strap that forms the lower straps 28 and 29 passes successively through pulleys 71, 75, and 73. The upper central strap 25 is divided into two parts forming a loop 67 that passes successively through pulleys 74, 72, and 76. Two flexible blades or rods 77 and 78 are mounted, by means of pivot joints 79 and 80, on the movable plates 65 and 66, respectively.

[0044] When the upper central strap 25 is moved away from the lower straps 28 and 29, the plates 65 and 66 move vertically towards each other. In this movement, the flexible blades or rods 77 and 78 bend. They therefore exert a restoring force opposing this relative movement of the straps 25, 28 and 29.

[0045] It is noted that one of the plates, 65 or 66, can be integrated into a housing of the casing 64.

[0046] To ensure that the blades deform in the desired direction, a certain offset is provided in the pivot joints 39 and 40 so that the force applied by the rod or blade has a moment about the pivot joint. Alternatively, the flexible rods or blades are pre-stressed or slightly curved at rest, the center of curvature then being on the same side of the blade or rod as the target center of curvature when the blade is fully folded.

[0047] In variants of the third embodiment, the number of pulleys is an even number other than six. The larger this number, the greater the amplitude ratio The relative movement of plates 65 and 66 on the amplitude of the relative movement of the central upper strap 25 with respect to the lower straps 28 and 29 is small. Again, by increasing this number, the dimensions of the housing 64 can be reduced, provided that the stiffness of the flexible blades or rods 77 and 78 is increased so that the same amplitude of user movement corresponds to the same restoring force.

[0048] In variations of the first three embodiments, the flexible rods or blades are not located in a plane parallel to the plane of the strap path, but are located in planes oblique or perpendicular to the plane of the strap path. In variations of the first three embodiments, flexible blades or rods are arranged in the plane of the strap path and in at least one plane perpendicular or oblique to this plane of the strap path.

[0049] The housing 84 of the fourth embodiment of the passive assistance device illustrated in [Fig. 8] comprises at least one flexible blade or rod 88 that deforms in a plane perpendicular to the plane of the strap paths. Each flexible blade or rod 88 is supported by pivot joints 80 mounted on plates, in the same manner as in the third embodiment. Each flexible blade or rod 88 can, in its folded configuration, extend beyond the surface of the housing 81 of the casing 84.

[0050] Thus, as illustrated in [Fig.9], each blade or flexible rod 88 can come to rest on the user's back at the level of his lumbar vertebrae when the user is leaning forward.

[0051] In alternative to each embodiment of the device of the invention, at least one upper strap and at least one lower strap together constitute a single strap. For example, starting from the embodiment illustrated in [Fig. 7], the strap 29 passes successively through pulley 73 and pulley 76, then joins the strap 25, another strand of which 29 passes through pulley 74 and then pulley 71.

[0052] The present invention applies to the technical field of equipment which provides assistance and relief to its user, particularly in the case of handling work of any kind, but also in the case of work involving a permanently inclined position of the trunk and, in particular, during repetitive manual work carried out, for example, by handlers.

[0053] As shown in [Fig. 2] and [Fig. 4], when the user leans forward, the thighs and shoulders move forward while the pelvis moves backward. These movements exert a progressive traction on the upper central strap 25 and the lower straps 28 and 29, which causes the flexible composite blades or rods in the housing of the passive assistance device to flex. These blades or rods thus accumulate mechanical energy, which is released when the user straightens up. The user is therefore relieved and assisted when standing up, thereby reducing effort and fatigue. Presentation of the invention

[0054] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0055] To this end, the present invention relates to a passive physical assistance device for applying a restoring force to a part of a user's body, comprising: - at least one first strap configured to be attached to that part of the user's body, - at least one second strap, and - a case comprising a first plate mechanically linked to each first strap and a second plate mechanically linked to each second strap, and, between these mechanical plates, at least one flexible blade or rod, whose elastic deformation varies according to the spacing between the plates.

[0056] By implementing at least one flexible blade or rod, the force can, during the relative movement of the plates, be increasing, constant, or decreasing as each flexible blade or rod deforms. The profile of the force curve as a function of the relative displacement of the plates varies, in particular, as a function of the offset of the axis of application of the force exerted by a plate on a flexible blade or rod, relative to the axis between the ends of the flexible blade or rod, on the one hand, and of the geometric arrangement of the ends of each blade or rod, for example, the angle between the axis of application of the force exerted by a plate on the flexible rod or blade and the axis between the ends of the rod or flexible blade, on the other hand.It is noted that the device which is the subject of the invention can be attached, by part of its straps, to a fixed support, for example a piece of furniture and, more particularly, to a seat on which the user can sit.

[0057] In some embodiments, the straps are attached to two parts of the user's body, on either side of at least one joint.

[0058] For example, such a joint is a hip, knee, shoulder, or elbow joint. As another example, it is a group of joints, the spine, the wrist, or the heel. The present invention thus applies to assisting movement of a large number of joints in the human body.

[0059] In embodiments, each first strap is connected to a chest harness and each second strap is connected to a leg sleeve of the user.

[0060] The present invention is therefore particularly applicable to the relief of the user's back muscles when bending forward.

[0061] In some embodiments, one of the mounting plates is fixed relative to the housing.

[0062] For example, a portion of the housing casing serves as a mounting plate.

[0063] In embodiments, the assistance device of the invention comprises, on at least one plate, a means for changing the direction of the force exerted by a single strap constituting each first strap or a single strap constituting each second strap.

[0064] Typically, this means for changing the direction of the force is a pulley or a smooth bearing. Thus, the single strap can be attached to two parts of the user's body, for example, their two shoulders or their two legs. The passage of this strap around the direction-changing means ensures compensation for the asymmetrical movements of these two body parts by limiting the displacement of the platform that carries this means. For example, when the single strap is attached at each end to one of the user's legs, a step corresponds to an elongation of the portion of the single strap between the advancing leg and the device housing, and a shortening of the other portion of the single strap between the leg remaining in contact with the ground and this housing. The same effect occurs during a twisting or flexion of the spine without changing the user's forward inclination.

[0065] In embodiments, the assistance device of the invention comprises, on at least one plate, at least two means for changing the direction of the force, each plate carrying at least one said means.

[0066] This results in a multiplication of the force applied by each flexible rod or blade on this plate on the user's body.

[0067] In embodiments, the assistance device of the invention comprises, on at least one plate, at least two means for changing the direction of the force exerted by the single strap, this strap passing through a said means mounted on one plate and through a said means mounted on the other plate.

[0068] This results in a multiplication of the force applied by each flexible rod or blade on each of the plates on the user's body.

[0069] In embodiments, the deformation of at least one flexible rod or blade is a bending in a plane parallel to a plane comprising a path for the passage of straps.

[0070] Thus, the device housing can be quite very thin.

[0071] In embodiments, the deformation of at least one flexible rod or blade is a bending in a plane perpendicular to a plane comprising a path for passing straps.

[0072] This flexible rod or blade can then press on a part of the human body, for example at the level of the lumbar vertebrae, to improve the user's comfort.

[0073] In embodiments, at least one flexible rod or blade comprises a composite material.

[0074] This type of flexible rod or blade has advantages in terms of weight, resistance to fatigue due to repeated deformation, and durability.

Claims

Demands

1. A passive physical assistance device (20) for applying a restoring force to a part of the body of a user (30), which comprises: - at least one first strap (25) configured to be attached to that part of the body of that user, and - at least one second strap (28, 29), characterized in that it further comprises a housing (24, 44, 64, 84) having a first plate (41, 42, 66) mechanically linked to each first strap and a second plate (34, 54, 65) mechanically linked to each second strap, and, between these mechanical plates, at least one flexible blade or rod (37, 38, 57, 58, 77, 78, 88), the elastic deformation of which varies according to the spacing between the plates.

2. Assistance device (20) according to claim 1, wherein the straps (25, 28, 29) are attached to two parts of the user's body (30), on either side of at least one joint.

3. Assistance device (20) according to any one of claims 1 or 2, wherein each first strap (25) is connected to a chest harness (21) and each second strap (28, 29) is connected to a leg sleeve (22, 23) of the user (30).

4. Assistance device (20) according to any one of claims 1 to 3, wherein one of the plates (41, 42) is fixed relative to the housing (24, 44).

5. Assistance device (20) according to any one of claims 1 to 4, comprising, on at least one plate (34, 41, 42, 54, 65, 66), a means (31, 32, 33, 51, 52, 53, 71 to 76) for changing the direction of the force exerted by a single strap (67) constituting each first strap (25) or a single strap constituting each second strap (28, 29).

6. Assistance device (20) according to claim 5, which comprises, on at least one plate (34, 41, 42, 54, 65, 66), at least two means (31, 32, 33, 51, 52, 53, 71 to 76) for changing direction, each plate carrying at least one said means.

7. Assistance device (20) according to claim 5, comprising, on at least one plate (34, 41, 42, 54, 65, 66), at least two means (31, 32, 33, 51, 52, 53, 71 to 76) for changing direction of the effort exerted by the single strap, this strap passing through a said means mounted on one plate and through a said means mounted on the other plate.

8. Assistance device (20) according to any one of claims 1 to 7, wherein the deformation of at least one flexible rod or blade (37, 28, 57, 58, 77, 78, 88) is a bending in a plane parallel to a plane comprising a path for straps (25, 28, 29).

9. Assistance device (20) according to any one of claims 1 to 8, wherein the deformation of at least one flexible rod or blade (37, 28, 57, 58, 77, 78, 88) is a bending in a plane perpendicular to a plane comprising a path for straps (25, 28, 29).

10. Assistive device (20) according to any one of claims 1 to 9, wherein at least one flexible rod or blade (37, 28, 57, 58, 77, 78, 88) comprises a composite material.

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