One garage creeper presently available on the market comprises a

90cm x 38cm rectangular piece of 20 gauge sheet metal mounted on

5 wheels. A mechanic lies flat on the sheet metal and propels himself by his heels into and out of the space beneath a vehicle upon which he is working.

Motor mechanics commonly suffer back injuries and discomfort and a result of working on these currently available creepers. In fact 10 back injuries force large numbers of mechanics to retire from the trade.

The currently available creepers can lead the tradesmen to adopt a poor work posture. Also the users of these creepers frequently slip off the metal plate sideways when exerting strenuous lateral l j force on some machinery being worked upon. This can lead to back injuries as also can the difficult manoeuvre of attempting to squirm back onto the creeper in a confined space- after slipping off sideways.

It is an object of the present invention to provide a worker 20 support which alleviates some of the problems of prior apparatus for supporting the back of a supine worker.

According to the present invention there is provided a worker support comprising a back support on which a person lies in use in a supine position to enable the person to v/ork in a space with low 25 vertical clearance, e.g. under a motor vehicle, ground engaging means for engaging with the ground so that the back support is generally level, the back support having an extent along a generally longitudinal direction along which the person's spine in use lies, the back support having sufficient rigidity to support the person's 30 back along a substantial part of the length of the spine, the back support being shaped to support the person's back in a physiologically compatible posture so as to reduce undesirable spinal deformation.

Preferably the back support includes a spinal support portion

35 extending in the general longitudinal direction and arranged to support the person's spine, the spinal support portion including a lumbar support portion for supporting the lumbar region of the

person's spine, the lumbar support portion being convex along a substantial part of the length thereof. In this embodiment, the lumbar support portion is preferably configured for supporting the lumbar region of the person's spine in a raised position relative to one or both regions of the back support adjacent to the lumbar support portion in one or in both opposite longitudinal directions.

In the preferrred embodiment the spinal support portion includes in order a sacrum support portion, the lumbar support portion and a thoracic support portion, the back support being continuously contoured along the spinal support portion so as to generally conform to the supine spinal shape, the sacrum support portion being of generally flat or shallow concave shape in the longitudinal direction, the sacrum support portion smoothly merging with the lumbar support portion, the lumbar support portion in turn smoothly merging with the thoracic support portion, the thoracic support portion having a concave shape.

The thoracic support portion may have a larger average radius of curvature in the longitudinal direction than the average radius of curvature of the lumbar support portion. The radius of curvature in the longitudinal direction for each point along the lumbar support portion may lie between SOOmm and 5000mm, and preferably between 1000mm and 2500mm, for the major part of the length thereof.

In one posssible embodiment, the lumbar support portion has a longitudinal extent for supporting a shorter than average height person, the v/orker support further including a selectively removable overlay for the lumbar support portion, the overlay having a sufficient thickness to effectively lengthen that portion when located thereon, the overlay tapering from a thicker central portion to thinner edge portions in both longitudinal directions so as to merge with the contour of the spinal support portion. The worker support may include two side support portions located on respective lateral sides of the longitudinally extending spinal support portion, the side support portions being arranged to support the person's back on opposite sides of the spine and to provide such support over substantially the full width of the person's body. The side support portions are preferably slightly lower than the spinal support portion, the side support portions merging smoothly with the spinal support portion so that the person's back can be supported in a natural posture without the person's spine thrusting downwardly

relative to the person's back on opposite sides of the spine. The side support portions may terminate in side edge support portions which project upwardly a short distance to enable lateral forces to be applied through the person's back against the back support without the person slipping laterally off the back support. Each of the edge support portions preferably includes an elongated slot extending generally longitudinally, the slots being located at waist level whereby the person may grasp the edge support portions at the slots with arms akimbo for manipulation of the worker support and for enabling the worker to comfortably rise to a sitting posture on the back support.

The worker support may further include an upper thigh support portion for supporting the person's upper thighs and to enable the person to use leg muscles to apply reactive forces during movement of the worker support or during the application of forces as part of carrying out work, the upper thigh support portion in transverse section including two laterally spaced concave portions for receiving and supporting the backs of the upper thighs of the person so that in transverse section through the upper thigh support portion there is a shallow V. shape. The ground engaging means for engaging with the ground and supporting the back support may comprise two shoulder wheels generally at the position of the person's shoulders and two thigh wheels provided at the positions of the upper thighs, the thigh wheels being capable of swivelling to enable changes in direction of movement of the worker support, the shoulder wheels being incapable of swivelling movement but being mounted for rotation about horizontal axes extending transverse to the longitudinal direction so as to enable the person to propel the worker support in forwards and rearwards directions and to change directional movement by sideways or crablike movements of the person's feet across the ground, the inability of the shoulder wheels to swivel enabling the person to apply lateral forces against a work object, the resultant reactive forces being transmitted through the worker support at general shoulder level without producing sideways rolling movement of the worker support.

Possible and preferred features of the present invention will now be described with particular reference to the accompanying drawings. However it is to be understood that the features illustrated in and

described with reference to the drawings are not to be construed as limiting on the scope of the invention. In the drawings:

Fig. 1 is a perspective view of a worker support according to a preferred embodiment of the present invention,

Fig. 2 is a transverse sectional view of the Fig. 1 back support at the thigh support portion, and

Fig. 3 is a side view of a human spine showing in broken line the approximate desirable longitudinal shape of the spine support portion.

The illustrated worker support comprises a back support 10 on which a person lies in use in a supine position to enable the person to v/ork in a space with low vertical clearance, e.g. under a motor vehicle, ground engaging means 30 for engaging with the ground so that the back support 10 is generally level, the back support 10 having an extent along a generally longitudinal direction A along which the person's spine 20 in use lies, the back support 10 having sufficient rigidity to support the person's back along a substantial part of the length of the spine 20, the back support 10 being shaped to support the person's back in a physiologically compatible posture so as to reduce undesirable spinal deformation. The back support 10 includes a spinal support portion 11 extending in the general longitudinal direction A and arranged to support the user's spine 20 in the desired posture. The spinal support portion 11 includes a lumbar support portion 12 "for supporting the lumbar region 21 of the user's spine 20 in a raised position relative to one or both regions 13, 14 adjacent to the lumbar support portion 12 in one or in opposite longitudinal directions.

In the preferred illustrated arrangement, the back support 10 includes in order, a ^" sacrum support portion 13, the lumbar support portion 12 and a dorsal or thoracic support portion 14. The lumbar support portion 12 is raised relative to both the sacrum and the thoracic support portions 13, 14.

The back support 10 is continuously contoured so as to generally conform to the supine spinal shape and for this purpose the spinal support portion 11 includes a shallow concave sacrum support portion 13 which continuously merges with a convex lumbar support portion 12 which in turn smoothly merges with a shallow concave thoracic support portion 14. The thoracic support portion 14 has a larger average

radius of curvature that the average radius of curvature of the convex lumbar support portion 12 thereby conforming generally to the human spinal column shape.

The dimensions of the spinal support portion 11 and particularly the dimensions of the sacrum, lumbar and thoracic support portions 13, 12, 14 may be varied for different user heights. That is, the worker support may be made in several size ranges to suit users of different heights. However it is expected that there is an optimum shape and dimensions for supporting in a suitable posture all "average" height users, say users having a height in the range of 168cm to 188cm. For "average" users, the total length of the back support 10 may be about 1 metre. The thoracic portion 14 may be about 30 to 35cm, the lumbar support portion may be about 25cm long, and the sacrum support portion about 10cm long.

Another possible means for ensuring proper back support for users of different heights is to manufacture the back support 10 for a smaller than average height user. The lumbar support portion 12 in this case may be too short to provide optimum support for a taller user, however there may be provided an overlay 26 for the lumbar support portion 12 of a sufficient thickness to effectively lengthen that portion when located thereon. The overlay 26 may be a thick panel or the like to be located at least on the lumbar support portion 12. The panel may taper from a thicker portion 27 to thinner edge portions 23 in both longitudinal directions to merge with the contour of the back support 10. The back support 10 may be made of a substantially rigid material or of components mounted sufficiently rigidly in a desired configuration to provide the desired user support. However it will be appreciated that firm component portions, e.g. padded support portions, may be supported either rigidly or supported so as to he selectively movable, e.g. movable longitudinally, but nevertheless by a sufficiently rigid underlying framework to support the user in the desired posture. The back support 10 for example may be made of a plastics material, e.g. by a moulding process. It will be understood by the skilled person that some suitable plastics materials nay require strengthening ribs or the like extending longitudinally and/or laterally beneath the back support 10.

The worker support includes a neck support portion 40 for supporting the neck and/or head of the user. The neck support portion 40 may be an integral part of or may be separately assembled with the back support 10. The neck support portion 40 comprises a cushioned support such as a cushion roll 41 extending generally 5 transverse to the longitudinal direction A.

Preferably the neck support portion 40 is selectively adjustable in the longitudinal direction A so as to enable user positioning of the neck support, e.g. at the base of the neck or at the base of the head. For this purpose the neck support portion 40 comprises a 0 cushion roll 41 carried by a support arm 42 extending longitudinally, the support arm 42 being telescopically selectively movable relative to the back support 10 in any convenient manner.

The back support 10 includes side support portions 15, 17 on both lateral sides of the spinal support portion 11, the side support 5 portions 16, 17 being operative to support the user's back on opposite sides of the spine 20 and preferably to the full width of the user's body. The side support portions 16, 17 are arranged so as to be slightly lower e.g. 1 to 3mm lower than but merging smoothly with the spinal support portion 11 since the human spine 20 is in a υ slightly depressed or concave portion of the back and the slight lowering of the side support portions 16, 17 enables the user's back to be supported in a natural posture without the spine 20 thrusting downwardly relative to the sides. For example if this were to occur at the upper back, the shoulder blades would be thrust forwardly

25 relative to their normal disposition in relation to the upper spine causing the shoulders to be hunched forwards. The overall width of the back support 10 may be 30 to 40cm, say about 35cm for back supporting along most of the length of the spine, and about 40cm wide at the shoulders. 0 .The side support portions 15, 17 extend laterally and terminate in edge support portions 19 which extend upwardly a short distance sufficient to enable lateral pressure to be applied through the user's back and against the back support 10 without the user slipping laterally off the back support 10. The edge support portions 19 need

- ^* - not extend along the full longitudinal length of the back support 10. Handles for ready carrying or manipulation of the worker support are defined by elongated slots 25 extending generally longitudinally in the two opposite edge support portions 19.

The preferred features of the edge, side and spine support portions 19, 16, 17, 11 as described above give the preferred back support 10 a continuous shallow W-shape in transverse cross section.

The back support 10 includes an upper thigh support portion 31 for supporting the user's upper thighs and to enable the user to use leg and particularly thigh muscles to apply reactive forces during movement of the worker support or during the application of forces during the carrying out of work. The upper thigh support portion 31 in transverse section includes two laterally spaced concave portions

32, 33 for receiving and supporting the Kacks of the upper thiyhs of the user so that in transverse section through the upper thigh support portion 31 there is a shallow W-shape. The upper thigh support portion 31 smoothly merges with a buttocks support portion 4? which in turn merges smoothly with the sacrum support portion 13.

The combined length of the buttocks support portion 43 and thigh support portion 31 may be about 30cm.

The ground engaging means 30 of the worker support comprises _y round engaging wheels 34, 35 although rollers, skids or other ground ^• enyaging means may be usable. Preferably there are provided at least three and preferably four ground engaging wheels 34, 35, the wheels 34, 35 being fairly widely dispersed so as to provide stable spaced supporting points for the back support 10. Two wheels 34 are provided generally at the shoulder positions and two 35 at the upper thigh positions. The tv/o upper thigh wheels 35 are castor wheels which can swivel to readily enable changes in direction of movement of the worker support. The shoulder wheels 34 are not capable of swivelling movement but are mounted for rotation about horizontal axes 37 directed transverse to the longitudinal direction A so as to enable the user to propel the worker support in forwards and rearwards directions and to change direction of movement by sideways or crab movements of the feet engaging the ground. The feature of not providing swivelling movement of the shoulder wheels ?- will enable the user to apply lateral forces against machinery or the like being worked upon, the reaction forces being transmitted through the worker support at general shoulder level not producing sideways rolling movement of the worker support as would happen if the shoulder wheels 34 could swivel.

The ground engaging wheels 34, 35 are relatively wide, e.g. of the order of an inch in width to provide for stability and durability. The wheels may be made of a material having some resiliency but also having durability. A suitable material may be neoprene. Suitable wheels may be of the general kind used on skate boards.

As mentioned previously the back support 10 may be made of plastics material. The back support 10 may be a continuous sheet of plastics material. Plastics material is believed to be preferable particularly for providing heat insulating properties for the user's back. This is particularly important for motor mechanics who can suffer back and related ailments due to cold. If desired a thermally insulating layer may be laid over the back support 10, e.g. a layer of "Thermos i ".

It will be seen that the worker support according to the preferred embodiment of the invention as herein described and illustrated can be used to support a worker's back in the supine position, with the spine 20 being supported in a natural posture. This enables the user to work more comfortably and to apply forces during working with the reaction forces being properly distributed. The user is supported comfortable and securely against slipping relative to the back support 10, even during application of lateral forces. The user can manoeuvre and move the support 10 readily, using leg and particularly thigh muscles for propulsion, rather than buttock muscles as is the case with presently available creepers. Also the shaping and materials of the back support 10 can provide insulation for retaining body heat in the back.

It is to be understood that various alterations and modifications of the worker support as described herein can be made. For example the back support 10 may include one or more compartments covered by a flexible material, the compartment(s) holding filling material so that the compart eπt(s) adopt the desired shape. For example a larger compartment may be provided in the lumbar region to support that portion of the user's back at a higher level.

It is to be understood that various alterations, modifications and/or additions may ^e made to the features of the possible and preferred embodiment(s) of the invention as herein described without departing from the spirit and scope of the invention as ef n _' " ¹ in the appended claims.