An exercise device

Abstract: An exercise device 1 is provided for holding the pelvis of a user in a substantially fixed position during exercising of the user's back and/or the user's leg. The device 1 comprises two independently adjustable support surfaces 3, 4, and two adjustable straps 5, 6 for extending around a user. By securely clamping the user's pelvis against the support surfaces 3, 4 in a substantially pain-free position using the straps 5, 6, and the user then performing back exercises and/or leg exercises, this will have a therapeutic effect on the user.

Description: Introduction This invention relates to a pelvic holding device for use during exercising. In particular it relates to a device for holding a pelvis fixed to treat and/or prevent disorders in the lower back/pelvis/hip joint region. Such a device is described e.g. in document US-A-5 688 212. In the human anatomy , the lower spine, known as the lumbar spine, is joined to the pelvic bone at a joint known as the sacro-iliac joint. The sacro-iliac joint is a relatively stiff or rigid joint. The upper leg bone, known as the femur, is joined to the pelvic bone at the hip joint by means of hip ligaments. Only a limited degree of movement of the lumbar spine relative to the pelvis is possible at the sacro-iliac joint, due to the relatively stiff or rigid nature of this joint. Thus, in general, upon movement of the lumbar spine in any direction, at least some of this movement is translated into a movement of the pelvis at the hip joint. This is because the hip joint is relatively free-moving in comparison to the stiff sacro-iliac joint. Upon movement of the leg, at least some of the hip ligaments start to wind up. When these hip ligaments are fully wound up, further movement of the leg is translated into a movement of the pelvis at the sacro-iliac joint. Disorders of the lower back/pelvis/hip joint region are a common and painful complaint. There is a need for a suitable means and method to effectively treat and/or prevent such disorders. Statements of Invention According to the invention there is provided a device for use during exercising for holding a pelvis of a user in a substantially fixed position thereby facilitating pivoting of the user's spine about the user's pelvis during back exercise, and/or facilitating pivoting of a leg of the user about the user's pelvis during leg exercise. In one embodiment the device substantially prevents pivoting of a user's pelvis about a hip joint of the user during exercising of the user's back. In another embodiment the device substantially prevents pivoting of a user's pelvis about the user's sacro-iliac joint and lumbar spine during exercising of a leg of the user. In claim 1 such a device is defined. The support body may define a plurality of support surfaces and the position of the support surfaces may be independently adjustable. Preferably the location of the support surface is adjustable. Ideally the inclination of the support surface is adjustable. The support surface may comprise at least one bolster or wedge. The support body may comprise at least one leg for supporting the support surface at a suitable height above ground level. Preferably the support body comprises a base from which the leg extends. Ideally the base defines a platform on which a user may stand during exercising. In another case the support body comprises means for attachment of the support body to a supporting structure. The attachment means may comprise a recess in the support body for co-operative mating with a corresponding protrusion on the supporting structure. Preferably the recess is provided in a side of the support body opposite to the support surface. Ideally the supporting structure is rigid, such as a wall, or a doorway, or a floor. The supporting structure may be an exercise machine. Desirably the support surface is of a resilient material, such as a foam, or a rubber. Ideally the support surface is contoured. The device may comprise a grippable bar to assist exercising of a user. Ideally the device comprises at least one exercise band attached to the bar. The bar is preferably supported by the support body. The device may comprise exercise weights to assist exercising of a user. Ideally the device comprises a pulley mechanism attached to the exercise weights. Most preferably the exercise weights are supported by the support body. The device is suitable for treatment of a back and/or a leg. The invention provides a use of the device of the invention for treatment. Preferably for treatment of a back, most preferably for treatment of a lumbar spine. In another case the use is for treatment of a leg. Desirably the use of the device relocates the position of a misaligned joint of a user. Furthermore there is provided a method of exercising a back, the method comprising the steps of:- holding a user's pelvis in a substantially fixed position; and exercising the user's back with the user's pelvis held substantially fixed to cause pivoting of the user's spine about the user's pelvis. In one embodiment the holding of a user's pelvis in a substantially fixed position substantially prevents pivoting of the user's pelvis about a hip-joint of the user during exercising of the user's back. Furthermore, there is provided a method of exercising a leg, the method comprising the steps of:- holding a user's pelvis in a substantially fixed position; and exercising a leg of the user with the user's pelvis held substantially fixed to cause pivoting of the user's leg about the user's pelvis. In one embodiment of the invention the holding of a user's pelvis in a substantially fixed position substantially prevents pivoting of the user's pelvis about the user's sacro-iliac joint and lumbar spine during exercising of a leg of the user. Preferably the method comprises the steps of:- providing at least one support surface; and clamping a user's pelvis against the support surface to hold the user's pelvis in a substantially fixed position using a holder. Ideally the method comprises the step of adjusting the position of the holder to suit a user. The method may comprise the step of adjusting the location of the holder. The method may comprise the step of adjusting the inclination of the holder. Most preferably the method comprises the step of adjusting the clamping tension in the holder to suit a user. In another case the method comprises the step of adjusting the position of the support surface to suit a user. A plurality of support surfaces may be provided, and the method may comprise the step of independently adjusting the positions of the support surfaces. Preferably the method comprises the step of adjusting the location of the support surface. Most preferably the method comprises the step of adjusting the inclination of the support surface. Desirably the adjustment is performed by a user. In a preferred embodiment a user's pelvis is clamped against the support surface in a substantially pain-free position before exercising The exercising may include a twisting movement, or a bending movement. The exercising may include bending substantially forwards and/or substantially backwards, or bending substantially to the side. The exercising may include a stretching movement, or movement against exercise weights or resilient bands, or an extension movement, or a flexing movement. The device according to the invention provides a means of therapeutically treating a back, in particular treating a lower back or lumbar spine region. The invention also provides a means of therapeutically treating a hip joint. The device according to the invention further provides a prophylactic means to prevent disorders of the lower back/pelvis/hip joint region from developing. By securely clamping a user's pelvis in a fixed position using the invention, and thereafter exercising the user's back and/or leg, a therapeutic effect is experienced at the lumbar spine/sacro-iliac joint/hip joint region. By securely clamping the pelvis of a user in a substantially pain-free position, the invention enables the user to perform movements or exercises, which would otherwise cause pain to the user if his/her pelvis was not restrained, without experiencing any pain. Performance of these pain-free exercises has a therapeutic effect on the user. The strap and support surface components of the invention may be quickly and easily adjusted to suite the user. In particular, the adjustment may be performed by the user himself/herself. This facilitates use of the device without direct supervision by, for example, a clinician. Self-adjustment also ensures that the most comfortable and pain-free position of use may be achieved. The adjustable nature of the invention enables all users, regardless of anatomical characteristics, or of their particular disorder to achieve the desired pain-free clamped position of use with a single device. The optimum pain-free position for a particular user may change from one exercise session to another exercise session, or during one exercise session as the invention has a therapeutic effect on the disorder of the user. The device according to the invention enables the user to adapt the device to ensure that the pain-free position of use is maintained. The device of the invention is suitable for use without requiring intensive supervision by another person, for example, a clinician. In particular, the device could be used in a home setting. Alternatively it could be used as part of a relatively large group being supervised by only one clinician. The device is relatively compact and lightweight, and is thus highly mobile. The device is, however, also stable during use due to its wide base. The invention allows exercise to be performed by a user in a highly convenient manner. In particular it is not necessary for the user to be in a lying position or for the user to undress to use the device. Brief Description of the Drawings The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a perspective view of a device according to the invention; Fig. 2 is a side view of the device of Fig. 1; Fig. 3 is a side, partially cross-sectional view of the device of Fig. 1 in use; Fig. 4 is a side, partially cross-sectional view of the pelvis and lumbar spine region of a human; Figs. 5 and 6 are side, partially cross-sectional views of the device of Fig. 1 in use; and Fig. 7 is a perspective view of another device according to the invention. Detailed Description Referring to the drawings there is illustrated a device for holding the pelvis of a user in a substantially fixed position during exercising of the user's back and/or the user's leg. By holding the user's pelvis substantially fixed, the device ensures that substantially all exercising movement of the user's back is translated into a pivoting of the user's spine about the user's pelvis, and the device substantially prevents pivoting of the user's pelvis about a hip joint of the user. Similarly, the device ensures that substantially all exercising movement of the user's leg is translated into a pivoting of the user's leg about the user's pelvis, and the device substantially prevents pivoting of the user's pelvis about the user's sacro-iliac joint and lumbar spine. The device is adjustable to ensure that the user's pelvis is held in a pain-free position, so that subsequent exercising movements are substantially pain-free. By performing these pain-free exercises, this has a therapeutic effect on the user. Referring in particular to Figs. 1 and 2, there is illustrated a device 1 according to the invention, the device 1 being suitable for treatment, in particular for treatment of a lower back/pelvis/hip joint region of a human. The device 1 comprises a support body 2, which defines at least one, and in this case two, support surfaces 3, 4, and a holder to clamp the pelvis of a user, in this case a patient, in a substantially fixed position against the support surfaces 3, 4. The holder is provided by two straps 5, 6 for extending around a patient. As illustrated in Fig. 1, the straps 5, 6 extend from a side wing 7 of the support body 2 and loop around to another side wing 8 of the support body 2. The straps 5, 6 are releasably attached to each side wing 7, 8 by means of, for example, clips or rope attachments. However, it will be appreciated that the straps 5, 6 may be integral with the support body 2 at one side wing, and may be releasably attached to the other side wing. Alternatively the straps 5, 6 may be integral with the support body 2 at both side wings 7, 8 with a release means, such as a clip or rope, provided intermediate the ends of each strap 5, 6. It will be appreciated, in any case, that any suitable means of attachment of the straps 5, 6 to the support body 2 may be employed, provided that the straps 5, 6 may be extended around a patient to facilitate clamping of the patient's pelvis against the support surfaces 3, 4. The position of the straps 5, 6 is adjustable, in particular the location on the side wings 7, 8 from which the straps 5, 6 extend may be adjusted up or down. In this case, the side wings 7, 8 define a plurality of recesses 9 spaced along the side wings 7, 8, the recesses 9 being configured to receive clips on each end of the straps 5, 6 in a releasable manner. The inclination at which the straps 5, 6 extend from the side wings 7, 8 may also be adjusted by pivoting of the ends of the straps 5, 6 in the recesses 9. The clamping tension in the straps 5, 6 may be adjusted by means of, for example, a ratchet mechanism or a pulley system provided at some point along the straps 5, 6. The straps 5, 6 are preferably of a tough, flexible material, similar to the fibrous material from which seat belts are made. In one case, soft foam pads are provided on the contact side of the straps 5, 6 for enhanced user comfort. The straps 5, 6 may have a high co-efficient of friction coating to prevent slippage of the straps 5, 6 relative to the user's clothing and/or body. In one case the straps 5, 6 have a rubbery finish. The position of the support surfaces 3, 4 is also adjustable, and preferably the position of each support surface is adjustable independently of the position of the other support surface. The support surfaces 3, 4 are releasably attached to the support body 2 by means of, for example, hand-releasable screws, and the location of the support surfaces 3, 4 along the support body 2 may be adjusted either up or down, as desired. The inclination of the support surfaces 3, 4 may be adjusted, for example by means of a hinge arrangement. In one case, the support surfaces 3, 4 at least partially comprise wedges or bolsters releasably attached to the support body 2 by means of hook and pile fastener material, such as Velcro. The wedges or bolsters may be selectively arranged on the support body 2 to ensure that the user is in a comfortable, pain free position clamped against the support surfaces 3, 4. The support surfaces 3, 4 are preferably of a resilient material, such as foam or rubber, to provide a sufficiently solid surface against which the patient's pelvis is to be clamped. In one case, the support surfaces 3, 4 may be contoured to accommodate the shape of a pelvis. Differently shaped support surfaces may be provided to suit a range of user anatomies. The support body 2 comprises a base 10, from which a leg 11 extends to support the support surfaces 3, 4 and the straps 5, 6 at a suitable height above ground level for use by the patient. The leg 11 may be a metal leg, for example of steel, and the leg 11 is rigidly connected to the base 10. The base 10 is sufficiently wide to ensure that the device 1 is stable even when in use by an exercising patient. In this case, the base 10 is configured to define a platform on which the patient stands when the patient's pelvis is clamped against the support surfaces 3, 4. The patient's body weight will thus provide a further stabilising effect to the device 1. It will be appreciated that more than one leg may be provided to support the support surfaces 3, 4, as desired. A stool 12 may be provided on the base 10 to provide a base for exercising a leg of the patient while the patient's pelvis is clamped against the support surfaces 3, 4. The stool height may be adjusted. A grippable bar 21 is supported by the support body 2. The bar 21 may alternatively be supported by the base 10, or a separate supporting structure. The bar 21 may be gripped by the patient and used to assist exercising of the patient's back and/or leg after the patient has been clamped against the support surfaces 3, 4. An elastic exercise band, or a pulley system may be attached to the bar 21 to assist patient exercising. The support body 2 may be provided with a means of attaching the device 1 to a separate rigid supporting structure, such as a wall, or a door, or a floor, or an exercising machine, for example an exercise weights machine. By providing such an attachment means the base 10 is not required. In one case, the attachment means comprises a recess in the side of the support body 2 opposite to the support surfaces 3, 4, the recess being configured to mate with a corresponding protrusion, such as a hook, on the supporting structure. In another case the attachment means comprises an additional bracket. Referring now to Figs. 3, 5 and 6, there is illustrated the use of the device 1 during exercising, in particular to treat the lower back/pelvis/hip joint region of a user, in this case a human patient 30. The legs 40 and feet 41 of the patient 30 are represented schematically in Figs. 3, 5 and 6 for convenience. In use, at least one end of the straps 5, 6 is detached from the side wings 7, 8. Alternatively, in the case where the straps 5, 6 are integral with the support body 2 at both side wings 7, 8, the release means intermediate the ends of the straps 5, 6 is opened. In either case, the patient 30 steps upon the base 10 and positions his/her pelvis 31 against the support surfaces 3, 4. The positions of the support surfaces 3, 4 may be adjusted, for example the location may be adjusted either up or down, or the inclination may be adjusted to suit the characteristics, such as the anatomy, of the patient 30. This is particularly advantageous if the support surfaces 3, 4 are contoured, as it is important that the patient's pelvis 31 is aligned with the pre-formed contours to prevent discomfort to the patient 30. The positions of the support surfaces 3, 4 may be adjusted independently of one another. This enables the patient 30 to achieve a comfortable position against the support surfaces 3, 4, despite any lack of symmetry in the pelvis 31, as frequently occurs in the non-ideal anatomies of actual patients. When the patient 30 is comfortably positioned with the pelvis 31 against the support surfaces 3, 4, the straps 5, 6 are looped around the patient 30, and either reattached to the side wings 7, 8, or alternatively the release means is closed. The position of the straps 5, 6 may be adjusted, for example the location may be adjusted either up or down, or the inclination may be adjusted. In addition, the clamping tension in the straps 5, 6 may be adjusted, for example, by using a ratchet mechanism or pulley system. The straps 5, 6 are so adjusted until the patient's pelvis 31 is securely clamped against the support surfaces 3, 4 in such a position that the patient is substantially free of any pain or discomfort in the back. A typical clamped position is illustrated in Fig. 3. In this case, strap 6 extends from the side wing 7 around a lower part of the patient's pelvis 31 to the other side wing 8, and strap 5 extends from the side wing 7 around a higher part of the patient's pelvis 31 to the other side wing 8. It will be appreciated that the desired clamped position varies depending on the particular user. The straps 5, 6 may extend around the user at any point on the user's body as long as the user is in a pain free position securely clamped against the support surfaces 3, 4. Advantageously, the adjustment of the straps 5, 6 and/or the adjustment of the support surfaces 3, 4 may be performed by the user himself/herself. This self-adjustment enables the user to best achieve a comfortable and substantially pain-free position clamped against the support surfaces 3, 4. Alternatively, another person, such as a supervising clinician, may assist in adjusting the straps 5, 6, and/or the support surfaces 3, 4. When such a position has been achieved, the patient 30 can then exercise his/her back, for example by bending backwards (Fig. 5), and/or by bending forwards (Fig. 6). The bar 21 may be gripped by the patient 30 to assist in exercising the back. Elastic exercise bands attached to the bar 21, and/or an exercise weight stack pulley system may be used to provide resistance to the exercises of the user. The bands and/or weights may be attached via a belt or harness to the user. The sacro-iliac joint 32 between the lumbar spine 33 and the pelvis 31 is illustrated in detail in Fig. 4. The sacro-iliac joint 32 is normally a relatively stiff or rigid joint, in particular in comparison to a relatively free-moving joint such as a hip-joint 34, or a shoulder-joint of the patient 30. Because the patient's pelvis 31 is securely clamped against the support surfaces 3, 4 by the straps 5, 6 during exercising of the back this ensures that all movement of the patient's back is translated into a pivoting of the patient's spine 33 about the patient's pelvis 31 which remains fixed (Figs. 5 and 6). The pelvis clamping arrangement of the straps 5, 6 substantially prevents pivoting of the pelvis 31 about the hip joint 34 during the back exercise, as would normally occur if the pelvis 31 was unconstrained. By mobilising the lumbar spine 33 to pivot about the pain-free positioned pelvis 31, the back exercise has a therapeutic effect on the patient 30. In a manner similar to that described above with reference to Figs. 5 and 6, the patient 30 can also exercise his/her leg 40 after the pain-free position clamped against the support surfaces 3, 4 has been achieved. Because the patient's pelvis 31 is securely clamped against the support furfaces 3, 4 by the straps 5, 6 during exercising this ensures that all movement of the patient's leg 40 is translated into a pivoting of the patient's leg 40 about the patient's pelvis 31 which remains fixed. The pelvis clamping arrangement of the straps 5, 6 substantially prevents pivoting of the pelvis 31 about the sacro-iliac joint 32 and lumbar spine 33 during the leg exercise, as would normally occur if the pelvis 31 was unconstrained. By mobilising the leg 40 to pivot about the pain-free positioned pelvis 31, the leg exercise has a therapeutic effect on the patient 30. It is believed that such pivoting of the lumbar spine 33 about the pelvis 31 and/or pivoting of the leg 40 about the pelvis 31 helps to relocate any fault which may have developed in the pathological position of the lumbar spine 33 relative to the pelvis 31 at the sacro-iliac joint 32 and/or of the leg 40 relative to the pelvis 31 at the hip joint 34. It is believed that by exercising with the pelvis 31 securely clamped in a pain-free position, the spine 33, and/or the pelvis 31, and/or the hip-joint 34 become correctly re-aligned. The exercising may additionally or alternatively include twisting or rotational movements, or stretching movements, or flexing movements or extending movements, or the lifting of exercise weights, or sideways bending or any other suitable exercise, as prescribed for the patient 30 by a clinician, for example. The straps 5, 6 and/or the support surfaces 3, 4 may be adjusted during the exercise session to ensure that the user is in a substantially pain-free position throughout the session. After a period of exercise either the straps 5, 6 are detached, or the release means along the straps 5, 6 is opened, and the patient 30 then steps away from the support surfaces 3, 4 and off the base 10. It has been found that after such an exercise session using the device of the invention, the reduced pain feeling or substantially pain-free feeling experienced by the user while clamped to the support surfaces 3, 4 persists. Referring now to Fig. 7, there is illustrated another device 50 according to the invention, which is similar to the device 1 of Figs. 1 to 6, and similar elements in Fig. 7 are assigned the same reference numerals. In this case, exercise weights 13 are provided in place of the grippable bar 21. The exercise weights 13 are provided on the support body 2, the weights 13 being attached to a pulley mechanism 14. The weights 13 are supported by the support body 2, and may be used by the patient to assist in exercising the patient's back and/or the patient's leg 40 after the patient has been clamped against the support surfaces 3, 4. It will be appreciated that the device according to the invention may be configured for use by a patient in a horizontal lying position instead of a vertical standing position. In this case, the device may be provided on, or as part of, a treatment table or bed. Alternatively the device may be configured for use by a patient inclined at any suitable angle. In one case the angle may be selectively adjustable to suit the needs of the patient. In a further case, the device according to the invention may be configured for use by a patient in a seated position. It will further be appreciated that the device could be used with a person who is clamped with the rear of his/her pelvis against the support surfaces, instead of the front of his/her pelvis, as illustrated in the drawings. The device according to the invention may be used to treat a patient who is suffering from a back complaint or back disorder, in particular a lower back disorder in the region of the lumbar spine/sacro-iliac joint/pelvis/hip-joint. It will, however, be appreciated that the device may be used who is not currently suffering from back discomfort. In this case, the invention will have a prophylactic effect and will help to prevent back complaints or back disorders developing. The invention is not limited to the embodiments hereinbefore described, with reference to the accompanying drawings, which may be varied in construction and detail within the scope of the claims.

Claims: A device (1) for holding the pelvis (31) of a user (30) in a substantially fixed position thereby facilitating pivoting of the user's spine (33) about the user's pelvis (31) during back exercise, and/or facilitating pivoting of a leg (40) of the user (30) about the user's pelvis (31) during leg exercise, said device (1) comprising: a support body (2) defining at least one support surface (3, 4); a holder to clamp the user's pelvis (31) in a substantially fixed position against the support surface (3, 4), said holder including first and second vertically spaced portions, with said first holder portion being extendable around a lower part of the pelvis (31) of the user (30) and the second holder portion being extendable around a higher part of the pelvis (31) of the user (30), the position of each of the first and second holder portions being independently adjustable relative to the support body (2) to facilitate vertical adjustment of each of said first and second holder portions; and means for adjusting the clamping tension in at least one of the first and second holder portions. A device as claimed in claim 1 wherein the device (1) substantially prevents pivoting of a user's pelvis (31) about a hip joint (34) of the user (30) during exercising of the user's back, preferably the device (1) substantially prevents pivoting of a user's pelvis (31) about the user's sacro-iliac joint (32) and lumbar spine during exercising of a leg (40) of the user (30). A device as claimed in claims 1 or 2 wherein at least one of the first and second portions of the holder comprises a strap (5, 6) for extending around the user (30). A device as claimed in claim 3 wherein each of the first and second holder portions comprises a strap (5, 6) for extending around the user's pelvis (31). A device as claimed in claim 3 wherein the strap (5, 6) extends from the support body (2), preferably the strap (5, 6) is releasably attached to the support body (2), or preferably the strap (5, 6) is integral with the support body (2), preferably the strap (5, 6) comprises a release means intermediate ends of the strap (5, 6). A device as claimed in any of claims 1 to 5 wherein the adjustment means comprises a ratchet mechanism associated with each holder portion. A device as claimed in any of claims 3 to 6 wherein the inclination at which the strap (5, 6) may extend around the user (30) is adjustable. A device as claimed in any of claims 1 to 7 wherein the support body (2) comprises at least one leg (11) for supporting the support surface (3, 4) at a suitable height above ground level, preferably the support body (2) comprises a base (10) from which the leg (11) extends, preferably the base (10) defines a platform on which a user (30) may stand during exercising, preferably the support body (2) comprises means for attachment of the support body (2) to a supporting structure, preferably the attachment means comprises a recess in the support body (2) for co-operative mating with a corresponding protrusion on the supporting structure, preferably the recess is provided in a side of the support body (2) opposite to the support surface (3, 4), preferably the supporting structure is rigid, preferably the supporting structure is a wall, or a doorway, or a floor, preferably the supporting structure is an exercise machine. A device as claimed in any of claims 2 to 8 wherein the support surface (3, 4) is of a resilient material, preferably the resilient material is a foam, or a rubber, preferably the support surface (3, 4) is contoured. A device as claimed in any of claims 2 to 9 wherein the device (1) comprises a grippable bar (21) to assist exercising of a user (30), preferably the device (1) comprises at least one exercise band attached to the bar (21), preferably the bar (21) is supported by the support body (2), preferably the device (1) comprises exercise weights (13) to assist exercising of a user (30), preferably the device (1) comprises a pulley mechanism (14) attached to the exercise weights (13), preferably the exercise weights (13) are supported by the support body (2). A device as claimed in any of claims 1 to 10 wherein the inclination of the support surface (3, 4) is adjustable. A device as claimed in any of claims 1 to 11 wherein the support surface (3, 4) comprises at least one bolster or wedge. A device as claimed in any of claims 1 to 12 wherein each end of said first and second holder portions is adjustable relative to the support body (2). A device as claimed in any of claims 1 to 13 wherein said support body (2) is adjustable to position the support surface (3, 4) to suit the user (30). A device as claimed in any of claims 1 to 14 wherein the support body (2) comprises a plurality of support surfaces (3, 4) and the position of the support surfaces (3, 4) are independently adjustable. A device as claimed in any of claims 1 to 15 wherein the holder clamps the user's pelvis (31) in a substantially pain-free position thereby facilitating substantially pain-free pivoting of the user's spine (33) about the user's pelvis (31) during back exercise, and/or substantially pain-free pivoting of a leg (40) of the user (30) about the user's pelvis (31) during leg exercise.

Inventors: HOFFMAN JONATHAN, HOFFMAN, JONATHAN
Applicants: BACKPROJECT CORP, BACKPROJECT CORPORATION
Application year: 2001
Main classification: A63B23
IPC codes: A61H1, A63B23