US20200222750A1

US20200222750A1 - Gait training device

Info

Publication number: US20200222750A1
Application number: US16/615,697
Authority: US
Inventors: David Salicio Castillo; Ophélie CHOUPIN; Stélian CAMARA DIT PINTO; Maëva LE CLECH
Original assignee: Assistance Publique Hopitaux de Paris APHP
Current assignee: Assistance Publique Hopitaux de Paris APHP
Priority date: 2017-05-22
Filing date: 2018-05-21
Publication date: 2020-07-16
Also published as: EP3634589A1; FR3066397A1; WO2018215383A1

Abstract

A gait training device includes a treadmill including a belt and rolling parts, and a frame on which the treadmill is mounted, the rolling parts including: a plurality of balls distributed around a central core, and a cage enclosing the plurality of balls in order to keep the balls on the central core while allowing them to be movable relative to the central core, the belt being able to slide over the balls and rotate the balls on the central core.

Description

TECHNICAL FIELD

The present invention relates to a gait training device, notably for the rehabilitation of patients having injuries or walking disorders or for the training of sportsmen. The invention finds applications in the medical field, for example for rehabilitation in traumatology, rheumatology and neurology, or in the sports field for walking or running training or instead in the field of simulators and video games for simulating the movements of a user.

PRIOR ART

Treadmills are known, both in the medical field and in the sports field, for training a patient, a sportsman or any other user to walk or to run. These treadmills enable a repetition of the number of steps at different speeds, or even slopes.
Numerous medical studies have demonstrated the interest of these treadmills for the rehabilitation of patients having injuries or rheumatological or neurological affections or for elderly patients for gait training. Indeed, it has been demonstrated that the use of a treadmill improves the walking performances of these patients compared to a conventional rehabilitation practiced uniquely with the aid of a therapist.
In the sports field, whether it is for training a top level sportsman or to practise an occasional physical activity, the treadmill makes it possible to reproduce, indoors, walking or running generally practised in the open air, with substantially identical effects on the body.
A conventional treadmill, such as that represented in FIG. 1 and referenced 10, generally comprises a frame 11 in which a rolling belt 12 is moved. This rolling belt 12 is an endless belt, that is to say forming a closed loop, made of flexible material driven and supported by pulleys or drums 13. The pulleys and/or drums 13 are mounted transversally in the frame 11, inside the rolling belt such that said rolling belt is taut between the two pulleys and/or drums 13. The pulleys and/or drums 13 are rotationally driven by a motor, not represented in FIG. 1, but generally housed in the frame, so as to make the rolling belt run.
A conventional treadmill 10 generally comprises a console 15 provided with a control keyboard for controlling, for example, the starting, the stopping, the speed and sometimes the tilt of the rolling belt 12 and a screen for viewing speed and slope data and/or medical data.
Moreover, a conventional treadmill generally comprises maintaining arms 14, fixed to the frame and positioned substantially vertically to the rolling belt 12. These maintaining arms 14 may be gripping handles that allow the user to synchronise his movements with the running of the rolling belt, in particular when the treadmill is used for sporting applications. The maintaining arms 14 may also be parallel bars, such as represented in FIG. 1, which enable a brachial support of the user during the movement of his legs, in particular when the treadmill is used for medical purposes.
Conventional treadmills have a drawback in terms of adaptability. Indeed, even if the conditions of running the rolling belt (running speed and tilt) can vary, these conditions respond to predefined parameters, determined independently of the user. The user, or his therapist, can choose the conditions of running the rolling belt from among a selection of predetermined conditions, but this selection of conditions is invariable whatever the user of the treadmill. The user thus has to adapt to the running rhythm of the rolling belt. Yet, certain patients, notably those having walking disorders, have difficulties following a regular and continuous walking rhythm. For these patients, walking on a rolling belt having a regular and continuous running generates falls. These patients cannot use a treadmill alone. A therapist has to watch over each of them at each instant in order to be able to intervene quickly in the event of a fall or risk of a fall.

SUMMARY OF THE INVENTION

To respond to the aforementioned problem of the adaptability of the user to the running rhythm of the rolling belt, the Applicant proposes a gait training device in which the running rhythm of the rolling belt is imposed by the user and not by the machine.
According to a first aspect, the invention relates to a gait training device comprising:

- a treadmill including a rolling belt and rolling members, and
- a frame on which the treadmill is mounted.

This device is characterised by the fact that it comprises a central core constituting a support structure for the rolling members and the rolling belt, and in that the rolling members comprise:

- a plurality of balls distributed around the central core, said central core comprising a plurality of first housings each suited to receiving one of the balls, and
- a cage enclosing the plurality of balls to maintain said balls on the central core while allowing them to be moveable relative to said central core, the rolling belt being able to slide over the balls and to rotate said balls on the central core.

In this device, the rolling belt is driven in movement along with the steps of the user. It is thus the user himself who imposes the speed of movement of the rolling belt.
In the description that follows, the gait training device will be described with reference to a XYZ coordinates system, in which the plane XZ is a plane parallel to the surface of the ground on which the gait training device is laid and in which the axis Y is an axis perpendicular to the plane XZ.
Moreover, in this description, the layout of the balls of the device will be described with reference to the central core which constitutes the base of the treadmill, that is to say the structure for supporting the rolling members and the rolling belt. This central core has a surface and an under-face, in substantially parallel planes, and a circumference or perimeter perpendicular to the surface and under-face planes. The surface is the face of the central core the closest to the walking surface of the user. The under-face is the face, opposite to the surface, the closest to the surface of the ground.
In the description, “around the central core” will be taken to mean all the faces, surfaces, contours and/or under-faces of the central core along which the rolling belt is liable to move.
In an advantageous manner, the rolling belt envelops the central core, the cage and the plurality of balls. Thus, the rolling belt may be moved in all directions of the walking surface.
Advantageously, the plurality of balls comprises sliding balls distributed on the surface of the central core and housed in first housings of said central core. These sliding balls enable the sliding of the rolling belt on the surface of the central core.
Advantageously, the plurality of balls comprises support balls distributed on the under-face of the central core and housed in first housings of said central core. These support balls enable the movement of the rolling belt.
Advantageously, the sliding balls have a diameter less than the diameter of the support balls.
Advantageously, the frame comprises an inner wall equipped with second housings, the second housings being suited to receive at least support balls placed right next to the support balls of the central core.
Advantageously, the support balls of the frame and the support balls of the central core are arranged respectively on either side of the rolling belt. This layout of the balls enables the rolling belt to be moved in a continuous, fluid, smooth manner which allows the user to move on the treadmill as on the ground.
Advantageously, the plurality of balls comprises positioning balls or rollers positioned laterally on the central core and housed in first housings of said central core.
Advantageously, the frame comprises positioning balls or rollers housed in second housings of the frame and each placed right next to a positioning ball or roller of the central core.
Advantageously, the positioning balls or rollers of the frame and the positioning balls or rollers of the central core are arranged respectively on either side of the rolling belt. This layout of the positioning balls or rollers contributes to the fluidity of movement of the rolling belt.
Advantageously, the gait training device comprises a safety device and/or a device for retaining the user able to be positioned vertically to the frame so as to reassure and/or to help to maintain the user, in particular when said user is a patient having walking disorders.
In an advantageous manner, the gait training device comprises an outer structure in which the assembly formed of the frame and the treadmill is mounted, and a tilt system connecting the frame and the outer structure to tilt said frame with respect to the outer structure. Such a configuration of the device makes it possible to simulate a sloping ground and to train a user to walk on a slope.

BRIEF DESCRIPTION OF THE FIGURES

Other advantages and characteristics of the invention will become clear on reading the description, illustrated by the figures in which:

FIG. 1 represents an example of treadmill according to the prior art.

FIGS. 2A and 2B represent views, respectively front and perspective views, of an example of gait training device according to the invention.

FIG. 3 schematically represents an example of treadmill of the gait training device of FIG. 2.

FIG. 4 schematically represents an example of the treadmill of FIG. 3 mounted in a frame of the gait training device according to the invention.

FIG. 5 schematically represents an example of the frame block of FIG. 4 mounted in an outer structure so as to be tiltable.

FIGS. 6A, 6B and 6C schematically represent top views of different alternatives of the tilt system of the frame block in the outer structure.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT

An exemplary embodiment of a gait training device in which the running rhythm of the rolling belt adapts to the user is described in detail hereafter, with reference to the appended drawings. This example illustrates the characteristics and advantages of the invention. It is however recalled that the invention is not limited to this example.
In the figures, identical elements are marked by identical references. For reasons of legibility of the figures, the size scales between represented elements are not respected.
FIGS. 2A and 2B represent a side view and a perspective view of the gait training device according to certain embodiments of the invention. This training device 100 comprises a treadmill 120 mounted in a frame 130 laid on the ground or on any other flat surface intended to receive the training device 100. The treadmill 120 is suited to be driven in movement by a patient or any other user, in walking position on said treadmill.
The frame 130 is a rigid structure, for example made of metal or plastic, hollow, in which the treadmill 120 is placed. The frame 130 may have, for example, a parallelepiped or cylindrical basin shape with narrowed neck making it possible to surround the treadmill 120 while leaving the surface of said treadmill free. The assembly constituted of the treadmill 120 and the frame 130 forms a frame block 110. In certain embodiments, the frame block 110 is directly laid on the ground or on any flat surface parallel to the ground. In other embodiments, which will be described hereafter, the frame block 110 is mounted in an outer structure 170 laid on the ground or on any flat surface parallel to the ground.
The treadmill 120 comprises a rolling belt 121 intended to be moved by sliding on rolling members 122-124. Indeed, as will be described in greater detail hereafter, the user taking steps on the treadmill generates a movement of the rolling belt on the rolling members. These rolling members comprise, as represented in FIG. 3, a plurality of balls 122-124 distributed around a central core 126 and housed in said core. The central core 126 may be a plate, for example parallelepiped or cylindrical, solid or partially hollow. The central core 126 may be made, for example, of titanium—which has the advantage of being very resistant—or steel—which has the advantage of being cheaper than titanium—or aluminium—which has the advantage of being light and of having a good hygienic level—or instead composite materials—which have the advantage of being particularly light. The central core 126 may also be made using several of the previously cited materials such as, for example, a composite material for the whole of the core with titanium reinforcements in order to make the core more impact resistant.
The central core 126 may comprise a plurality of housings 127, called first housings, each suited to receiving one of the balls 122-124. In certain alternatives, each housing 127 is hollowed out in the material forming the central core 126. In other alternatives, the central core 126 is manufactured, for example by moulding, with the plurality of housings 127. Depending on the material chosen for the central core 126, reinforcements, for example made of titanium, may be arranged in the housings or in the vicinity of said housings 127 in order to reinforce the structure of the core and/or to facilitate the sliding of the balls 122-124 in their respective housings.
A cage 125 is provided around the central core 126 to enclose the balls 122-124 in order to maintain them in their respective housings 127 while allowing their mobility in said housings. The cage 125 of the central core may be a box—of substantially identical shape to that of the central core 126 but of dimensions substantially greater—of which the walls comprise openings facing the housings 127 of the central core 126. According to an alternative, the cage 125 may be a rigid or semi-rigid reinforcement, of wire mesh type, comprising openings facing the housings 127 of the central core 126. The openings in the box or in the reinforcement have dimensions enabling the partial crossing of the balls 122-124, that is to say the crossing of a portion less than half of the sphere forming each of the balls, this portion being called “outer part of the balls”. Thus, each of the balls 122-124 is placed in a housing 127 of the central core 126 and passes in part through an opening of the cage 125 so as to extend beyond said cage while remaining maintained between the central core 126 and the cage 125.
The rolling belt 121 is an envelope made of a flexible material, of tissue or rubber type, mounted and stretched around balls 122-124. The material of which the rolling belt 121 is formed has a predetermined elasticity and a structure making it possible to form an envelope which surrounds the totality of the assembly formed of the central core 126, the cage 125 and the balls 122-124. The rolling belt 121 is thus in contact with the outer part of each ball 122-124, that is to say with the part of each of the balls which is outside of the cage 125. In this way, any movement of the rolling belt 121 is accompanied by a rotation of the balls 122-124 in their respective housings 127.
The treadmill 120 may take the form, for example, of a cuboid or a cylinder of which the height is small compared to the side (if cuboid) or radial (if cylinder) dimensions. In other words, the section of the treadmill 120 may have a parallelogram shape, for example a rectangle, or a disc shape. In the examples of FIGS. 2A and 2B, the treadmill 120 has a flat cylinder shape and comprises a cylindrical central core 126, surrounded by a cylindrical cage 125, itself surrounded by a rolling belt 121 forming a cylindrical envelope.
Housings 127, each intended to accommodate one of the balls 122-124, are distributed on the surface 126 a and the under-face 126 b of the cylindrical central core 126 as well as on its circumference 126 c. According to certain embodiments, and as represented in the example of FIG. 3, the balls 122-124 are distributed on the central core 126 depending on their function. For example, sliding balls 122, intended to ensure the sliding of the rolling belt 121, are distributed on the surface 126 a of the central core; support balls 124, intended to support the central core 126 and to ensure the movement of the rolling belt 121, are distributed on the under-face 126 b of the central core; positioning balls 123, intended to ensure the positioning of the central core in the frame and the movement of the rolling belt 121, are distributed on the circumference of said central core 126.
The sliding balls 122 are, according to certain embodiments, of dimensions less than the dimensions of the support balls 124 and the positioning balls 123. The sliding balls 122 preferably have a diameter less than 10 mm so as to ensure, for the user, a sensation of platitude while walking. They may have, for example, a diameter of 5 mm. The small dimensions of the sliding balls 122, compared to the support balls and to the positioning balls, allows the rolling belt 121 to slide on the central core 126, that is to say to be moved in a continuous and fluid manner, while developing minimum effort. It further allows the user not to feel, under his feet, the undulations of the balls and to give him the sensation of walking on a flat structure like the ground.
The support balls 124 and the positioning balls 123 are balls of dimensions greater than the dimensions of the sliding balls 122 and of which the role is to ensure the movement of the rolling belt around the central core 126. In an alternative, the support balls 124 and 134 have a diameter greater than that of the positioning balls 123 and 133. The positioning balls 123, 133 may have, for example, a diameter of the order of ten times the diameter of the sliding balls 122. The support balls 124, 134 may have, for example, a diameter of the order of twenty times the diameter of the sliding balls 122. In particular, the positioning balls may have a diameter of 50 mm and the support balls a diameter of 100 mm.
These support 124 and positioning 123 balls are each associated with an identical ball, positioned in the frame. Each support 124 and positioning 123 ball of the treadmill 120 is adapted to interact with, respectively, a support ball 134 and a positioning ball 133 of the frame 130. Examples of pairs of support balls 124, 134 and pairs of positioning balls 123, 133 are represented in FIG. 4. As shown in FIG. 4, the support balls 134 of the frame 130 and the positioning balls 133 of the frame 130 are housed in housings 137, called second housings, arranged in the inner wall 131 of the frame 130. A frame cage 135 is mounted at least partially along the inner wall 131 of the frame so as to maintain the support 134 and positioning 133 balls in their housings 137. As for the cage 125 of the central core, the cage 135 of the frame may be a rigid or semi-rigid reinforcement, of wire mesh type, comprising openings facing housings 137 of the frame. According to an alternative, the cage 135 of the frame may be a U-shaped receptacle—with dimensions substantially less than the dimensions of the inner wall 131—of which the walls comprise openings facing the housings 137 of the frame 130. The openings in the receptacle or in the reinforcement have dimensions enabling the partial crossing of the balls 133-134, that is to say the crossing of a portion less than half of the sphere forming each of the balls, this portion being called “outer part of the balls”. Thus, each of the balls 133-134 is placed in a housing 137 of the frame 130 and passes in part through an opening of the cage 135 so as to extend beyond said cage while remaining maintained between the frame 130 and the frame cage 135.
The support balls 124 of the central core and the support balls 134 of the frame are identical balls, of same dimensions and made of the same material. Each support ball 124 is positioned facing a support ball 134 and is separated from said ball 134 by the rolling belt 121. Each support ball 134 is mounted by swivel link in a housing 137 of the frame.
Similarly, the positioning balls 123 of the central core and the positioning balls 133 of the frame are identical balls, of same dimensions and made of the same material. Each positioning ball 123 is positioned facing a positioning ball 133 and is separated from said ball 133 by the rolling belt 121.
Thus, the rolling belt 121, which envelops the central core 126 and the set of balls 122-124 of the core, is positioned so as to separate the support balls 124 of the core from the support balls 134 of the frame and the positioning balls 123 of the core from the positioning balls 133 of the frame. The interaction between the support balls 124 of the core and the support balls 134 of the frame makes it possible to limit the zones of the rolling belt in contact with the frame and/or the core and thus to limit rubbing of the rolling belt during movements thereof. The movement of the rolling belt 121 on the sliding balls 122 is thereby facilitated such that the patient does not notice this movement under his feet.
The interaction between the positioning balls 123 of the core and the positioning balls 133 of the frame makes it possible both to ensure the correct positioning of the rolling belt 121 around the central core 126 and to help the movement of said rolling belt on the rolling balls 122. The positioning balls 123, 133 make it possible, moreover, to stretch the rolling belt so that it is not in contact with the cage 125 of the central core.
In certain embodiments, the positioning balls 123 and the positioning balls 133 are in a cylindrical form, of roller type, positioned along axes parallel to each other. The movement of the rolling belt 121 thus leads to a rotation of each of the rollers 123, 133 in opposite directions of rotation.
It will be understood from the preceding that the structure of the frame 130 surrounds the treadmill 120 except for the upper face of the rolling belt 121—also called walking surface—which is intended to accommodate the user. When the user takes steps on the treadmill 120, the rolling belt 121 is translationally driven by the sliding balls 122. In other words, the rolling belt slides on the sliding balls. The positioning balls 123, 133 and the support balls 124, 134 accompany this sliding such that the rolling belt can be translated in all directions of the plane containing the walking surface 121 s. In this manner, it is the user who imposes his walking rhythm on the training device. The user is thus not constrained to adapt to a rhythm imposed by the machine; he can evolve at his rhythm on the treadmill and it is the rolling belt which follows his movements. In applications in the medical field, the training device as it has been described favours proprioception with unforeseeable changes of rhythm and direction.
In certain embodiments, in particular those applied to the medical field represented in FIGS. 2A and 2B, the training device comprises a safety device 140 ensuring notably the balancing or the maintaining of the patient. This safety device 140 may comprise, for example, an annular structure 141 adapted to surround the patient and to delimit a walking space. This annular structure 141 may be equipped, at its centre, with an inflatable ring 142 of dimensions adaptable to the corpulence of the patient. This inflatable ring 142 may be a plastic or rubber crown of which the inner circumference is variable and of which the outer circumference is adapted to the annular structure 141.
In an alternative, the inflatable ring 140 is a hollow crown, filled with a gas, for example air, of the child's inflatable ring or air chamber type. The pressure of the gas inside the inflatable ring 142 can vary as a function of the corpulence of the patient or of the desired support.
In an alternative, the annular structure 141 and the inflatable ring 142 may be equipped with a door system making it possible to open and to close the annular structure and the inflatable ring to enable the installation of the patient on the treadmill 120.
The safety device 140 may comprise, moreover, telescopic feet 143 fixed on the annular structure 141 to ensure a vertical movement of said annular structure as well as the inflatable ring 142. These telescopic feet 143 may be laid on the ground, around the frame 130, or instead fixed in bases 111 integral with the frame 130. These telescopic feet 143 make it possible to lower the annular structure and/or the inflatable ring to enable the installation of the patient on the treadmill 120 and to raise them to maintain the patient.
The inflatable ring 142 may be used to support the patient and to help him conserve a standing position. In this case, the inflatable ring must be sufficiently blown up to go round the waist of the patient. The inflatable ring 142 may also be used to help the patient keep balance and to reassure him. In this case, the inflatable ring must be blown up less so as to surround the patient without maintaining him.
The training device may also comprise a system for retaining 150 the patient. This retaining system may be in the form, for example, of a harness 151 making it possible to retain the patient in the event of a fall. This harness 151 may be fixed onto the annular structure 141, or onto any other structure situated in the vicinity of the treadmill 120, by means of fasteners 152. These fasteners 152 may be, for example, equipped with a locking ratchet associated with an accelerometer such that the harness 151 is locked as soon as an acceleration threshold corresponding to a fall of the patient is detected.
In certain embodiments, the gait training device comprises motors connected to the support balls and/or to the positioning balls in order to control the speed of movement of the rolling belt 121 and, in particular, to avoid any acceleration of said rolling belt. These motors, positioned in the frame 130, for example in the vicinity of the support balls 124, are connected to a control unit able to control the speed and/or the direction of rotation of the support and/or positioning balls.
In certain embodiments, the frame block 110 such as it has been described is mounted in an outer structure 170, itself laid on the ground. The outer structure 170 may be made, for example, of the same material as the frame 130 and have a shape similar to said frame but of larger outer and inner dimensions such that the frame block in its entirety can be contained within the outer structure. The frame block 110 may be fixed in the outer structure 170. The frame block may also be moveable in the outer structure thereby making it possible to tilt the surface 121 s of the treadmill 120 with respect to the surface of the ground, that is to say with respect to the plane XZ. Such a tilt makes it possible to simulate, for the patient, an upslope and/or a downslope. In these embodiments, of which an example is represented in FIG. 5, the gait training device 100 comprises a tilt system 160 able to tilt the frame block 110, formed of the frame 130 and the treadmill 120, with respect to the plane XZ. In these embodiments, the frame block 110, such as described previously, is mounted in an outer structure 170 and connected to said outer structure by the tilt system 160. This tilt system 160 may be controlled to move, in the direction Y, a part at least of the frame block 110 such that said frame block is tilted by a predetermined angle with respect to the plane XZ.
To do so, the tilt system 160 may comprise, for example, at least two jacks 161-164 both positioned between the outer structure 170 and the frame 130. The jacks may be two in number, for example the jacks 161 and 162, positioned at locations opposite to each other on the frame. In the case of a rectangular frame block, one of the jacks is positioned at the front of the treadmill whereas the other jack is positioned at the rear of the treadmill. In the case of a round frame block, the two jacks 161, 162 are positioned on either side of the diagonal of said frame block, as represented schematically in FIG. 6A. The opposite jacks 161, 162 are fixed on the outer structure 170 by pivot links so as to enable a tilt of the treadmill 120 in one direction or in the other. The activation of the jacks 161 and/or 162 makes it possible to generate a positive slope (upslope) or a negative slope (downslope) of a variable angle. The tilt of the two jacks in opposition 161, 162 enables a relatively high degree of slope for a reduced jack travel.
According to an alternative, the tilt system 160 may comprise two jacks 161, 164 distributed on a same half of the frame block and a pivot 165 fixed on the other half of the frame block 110, as represented schematically in FIG. 6B. In the case of a rectangular frame block, the two jacks 161, 164 may both be fixed to the front of the frame block 110, by swivel links on the outer structure 170 and by pivot links on the frame block. The pivot 165 is then fixed to the rear of the frame block. In the case of a round frame block, the two jacks 161, 164 may both be fixed on a same half-circumference of the frame block 110, by swivel links on the outer structure 170 and by pivot links on the frame block. The pivot 165 is then fixed on the other half-circumference of the frame block, as represented in FIG. 6B. In this alternative, one part only of the frame block rises with respect to the plane XZ whereas the other part pivots. This alternative, relatively simple to use, enables a more solid fixation but a lower degree of slope than the alternative of FIG. 6A.
According to another alternative, the tilt system 160 may comprise three jacks 161, 163, 164 distributed on the contour of the frame block, as represented schematically in FIG. 6C. They may be distributed, for example, so as to form an equilateral triangle. Each jack 161, 163, 164 may be fixed by a swivel link on the frame block and by a pivot link on the outer structure 170. This alternative makes it possible to generate all sorts of tilts, which makes it possible to simulate for example a movement on variable slopes.
Although described through a certain number of examples, alternatives and embodiments, the gait training device according to the invention includes various alternatives, modifications and improvements which will be clear in an obvious manner to those skilled in the art, obviously these alternatives, modifications and improvements form part of the scope of the invention.

Claims

1. Gait training device comprising:

a treadmill including a rolling belt and rolling members;

a frame on which the treadmill is mounted, and

a central core constituting a structure for supporting the rolling members and the rolling belt,

wherein the rolling members comprise:

a plurality of balls distributed around the central core, said central core comprising a plurality of first housings each suited to receiving one of the plurality of balls, and

a cage enclosing the plurality of balls to maintain said plurality of balls on the central core while allowing them to be moveable relative to said central core,

the rolling belt being able to slide over the plurality of balls and to rotate said plurality of balls on the central core.

2. The gait training device according to claim 1, wherein the rolling belt envelops the central core the cage and the plurality of balls.

3. The gait training device according to claim 1, wherein the plurality of balls comprises sliding balls distributed on the surface of the central core and housed in first housings of said central core.

4. The gait training device according to claim 1, wherein the plurality of balls comprises support balls distributed on the under-face of the central core and housed in first housings of said central core.

5. The gait training device according to claim 3, wherein the sliding balls have a diameter less than a diameter of the support balls.

6. The gait training device according to claim 5, wherein the frame comprises an inner wall equipped with second housings, the second housings being suited to receiving at least support balls placed right next to the support balls of the central core.

7. The gait training device according to claim 6, wherein the support balls of the frame and the support balls of the central core are arranged respectively on either side of the rolling belt.

8. The gait training device according to claim 1, wherein the plurality of balls comprises positioning balls or rollers positioned laterally on the central core and housed in first housings of said central core.

9. The gait training device according to claim 8, wherein the frame comprises positioning balls or rollers housed in second housings of the frame and each placed right next to a positioning ball or roller of the central core.

10. The gait training device according to claim 9, wherein the positioning balls or rollers of the frame and the positioning balls or rollers of the central core are arranged respectively on either side of the rolling belt.

11. The gait training device according to claim 1, further comprising a safety device and/or a device for retaining the user able to be positioned vertically to the frame.

12. The gait training device according to claim 1, characterised in that it comprises further comprising:

an outer structure in which the assembly formed of the frame and the treadmill is mounted, and

a tilt system connecting the frame and the outer structure to tilt said frame with respect to the outer structure.