WO2005049149A1

WO2005049149A1 - An exercise machine

Info

Publication number: WO2005049149A1
Application number: PCT/AU2004/001607
Authority: WO
Inventors: Michael Robertson
Original assignee: Michael Robertson
Priority date: 2003-11-21
Filing date: 2004-11-19
Publication date: 2005-06-02
Also published as: NZ529705A

Abstract

An exercise machine (1) includes a base (2), a pair of foot supports (4a, 4b), guide means (6a, 6b) to accommodate sliding of the pair of foot supports away from and toward each other and body support means (8a, 8b). The body support means is adjustable relative to the guide means to stabilise a user facing in one of a plurality of directions when using the exercise machine. To use the exercise machine, a user places a foot on each of the pair of foot supports and slides the foot supports apart to assume a stretched position in which leg muscles are stretched. To exit the stretched position the user contracts the leg muscles to slide the foot supports together.

Description

AN EXERCISE MACHINE

Field of the Invention This invention relates to exercise machines, particularly exercise machines that improve a user's strength and flexibility.

Background to the Invention Strength and flexibility are characteristics which play an important role in fitness and athletics. Dancers, gymnasts and martial arts experts in particular rely heavily on their strength and their superior flexibility to perform and compete at an elite level. Many techniques exist for improving flexibility. These include stationary and moving stretches and stretches which are performed alone or with a partner. One type of stretching which has become especially popular among elite athletes employs the principle of Proprioceptive Neuromuscular Facilitation and is commonly referred to as "PNF Stretching". PNF stretching is widely regarded as one of the best and fastest methods of achieving an increase in overall flexibility in target muscle groups. PNF stretching techniques were originally developed by physiotherapists in the 1940's to assist in the rehabilitation of patients affected by paralysis and the techniques have been developed to encompass a variety of methods. These methods are based on neurophysiological factors that bring about neural inhibition of the muscle undergoing the stretch. In simple terms, when stretching using PNF techniques, a target muscle group is stretched to its maximum range of motion (ROM) and the target muscles are then contracted for a short period of time, typically 6 to 8 seconds. Although the response is not well understood, it is believed that the voluntary contraction of the muscle triggers a reflex in the Golgi tendon organs resulting in a lengthening reaction which causes stretch receptors in the muscle spindle to accommodate a greater muscle length. When the contraction is relaxed, the muscle's resistance to being stretched is momentarily reduced, making it possible to increase the ROM slightly when the stretch is reapplied. PNF stretching is usually conducted with a training partner. After the subject performs the initial maximum ROM stretch, the partner holds the relevant limb in the stretched position to provide resistance against movement while the subject performs contraction of the same muscle group. It is important that the subject and the training partner are in constant communication so that the training partner does not apply excessive resistance to the subject when contracting as this may easily result in overstretching and serious damage to the muscle fibres.

Summary of the Invention In a first aspect of the present invention, there is provided an exercise machine including: a base; a pair of foot supports; guide means to accommodate sliding of the pair of foot supports away from and toward each other; and body support means, adjustable relative to the guide means, to stabilise a user facing in one of a plurality of directions when using the exercise the machine; wherein a user places a foot on each of the pair of foot supports and slides the foot supports apart to assume a stretched position in which leg muscles are stretched, and exits the stretched position by contracting the leg muscles to slide the foot supports together. The base is preferably placed on a floor or other supporting surface on which the exercise machine is to be used. The base may be of any suitable shape or cross section and may consist of a plurality of base members or feet to facilitate distribution of the mass of the exercise machine over the supporting surface. In some embodiments, it may be desirable to have a base which distributes the mass of the exercise machine over a larger area to ensure that the machine remains stable when in use. In other embodiments, stability may be achieved by manufacturing the base from a particularly heavy material and/or anchoring the base to the supporting surface. The foot supports may be foot platforms, pads or other suitable means for supporting the mass of the user. Accordingly, each foot support may house all or part of the foot as well as providing a support for the base of the foot. Foot retaining means may be provided on each of the foot supports to ensure that the user's foot is securely retained on the foot support and does not slide when the user assumes or exits the stretched position. The foot retaining means may be in the form of a band or strap, a foot cup, a textured surface on the foot support, or employ any other suitable means. In a preferred embodiment, the foot supports have a rubberised surface to provide extra cushioning to the user and prevent foot slippage. Further, the foot supports may have a portion of gradually increasing thickness along the inside edge of each foot support providing a "lip" which prevents the user's foot from sliding off the foot support when assuming, holding, contracting or exiting the stretched position. The guide means may be in the form of tracks, beams, rails or other suitable means which facilitate sliding of the foot supports toward and away from each other with little or no friction or resistance to sliding. When the foot supports slide in a straight line, the guide means may be provided by a single track, beam or rail upon which the foot supports slide. In such an embodiment, the guide means may have a central point away from which the foot supports slide when the user moves into the stretched position and toward which they slide when the user exits the stretched position. Alternatively, each foot support may slide on separate guide means which are joined at a central point. The guide means may be rectilinear to accommodate a straight angle between the user's left and right legs when in the stretched position. Preferably the attitude of each of the guide means is adjustable relative to the horizontal to accommodate inclined, straight or declined sliding of the foot supports. When in a declined arrangement, the guide means form an inverted "V" wherein the user's legs form an acute or an obtuse angle. This assists the user in adopting the principles of Proprioceptive Neuromuscular Facilitation (PNF) when stretching. When in an inclined arrangement, the guide means form a "V" and the user's legs form a reflex angle or "hyper-stretch" when in the stretched position. This arrangement is suitable for training very flexible users. Preferably the exercise machine includes biasing means for returning the foot supports to a "home position" when the user is not sliding the foot supports apart. Biasing means may be provided in any suitable form, such as by way of a spring arrangement or using a hydraulic, magnetic, counterweight or other suitable system. Preferably, the exercise machine further includes linking means to link movement of the two foot supports so that they remain equidistant from the home position during use either with or without biasing means. This may occur by way of a cable system, electronic or pneumatic drive or other suitable means to ensure that movement of the two foot supports along the guide means is balanced to bring about an even stretch. It is preferred that the linking means adds little or no resistance to the foot supports sliding along the guide means. However, in some modes of use it may be desirable to incorporate a level of resistance to sliding so that the relevant leg muscles can be trained in strength as well as flexibility. The exercise machine may also include stopping means to preclude movement of at least one of the foot supports until a suitable force has been applied so that the foot supports do not slide out from under the user when the user mounts the exercise machine. Moreover, the stopping means may be configured to prevent biased foot supports from hitting each other when they automatically return to the home position. Preferably, the stopping means includes a detent and roller arrangement. The exercise machine may also include end means to limit the distance over which one or both of the foot supports slide. Inclusion of end means at a suitable location along the guide means minimises the risk of muscle damage due to overstretching by ensuring that the foot supports do not slide apart further than the user's leg length and flexibility can accommodate. Accordingly, inclusion of end means is particularly suitable for ensuring safe use of the exercise machine by beginners who may not be flexible enough to assume a deep stretch. Preferably the end means are removable and can be located at different positions along the length of the guide means to incrementally increase or decrease the effective distance over which the foot supports slide. By positioning the end means at a suitable location along each of the guide means, the exercise machine can accommodate shorter users and users with shorter legs. Preferably the foot supports are adjustable to accommodate a range of foot orientations such as by tilting and/or swivelling. Accordingly, one or both of the foot supports may be parallel with the ground, inclined toward the base or inclined away from the base. In addition or as an alternative, the foot supports may be adjusted to accommodate orientations in which the users feet are in line with the guide means, perpendicular to the guide means, or at any angle therebetween. This facilitates flexion or extension at the ankle, depending on the orientation or angle of the foot supports and provides for more comfortable stretching. Preferably, the orientation of each of the pair of foot supports is independently adjustable. This is particularly suitable when using the exercise machine to improve flexibility in the "front stretch" position since the front and back feet are likely to be oriented and/or flex in different directions. In another embodiment, the orientation of the foot supports may be self adjusting or controllably adjustable whilst the user assumes or exits the stretched position. Adjustability of the body support means relative to the guide means facilitates stabilisation of the user when facing in one of a plurality of directions when using the exercise machine. These directions may include a first direction in which the user faces along the guide means, a second direction in which the user faces away from the guide means and any direction between the first and second directions. In the first direction, the user can comfortably perform a front stretch. In the second direction, the user can comfortably perform a side or adductor stretch. In one embodiment, the body support means may be adjusted by swivelling or rotating the body support means relative to the guide means and the base, and locking the relative position of these parts to prevent them from moving during use of the machine. In a preferred embodiment, the body support means is adjustably attached to the base and includes a handle positioned either side of the user. Preferably, the handles are grasped by the user's hands. As an alternative, they may be placed under the user's armpit, elbow or other part of the arm to stabilise the user when assuming, holding or contracting the stretched position and assist the user when exiting the stretched position. It is to be understood that any other type of body support means, such as a harness or belt supporting the chest, waist or torso, may be used. Preferably, the exercise machine further includes control apparatus having a timing device, input and output means and a memory component. Preferably, the control apparatus is positioned so that the user can view and/or access the control apparatus display whilst using the machine. It is also preferred that the control apparatus is programmable with a stretching routine in which leg muscles are stretched and the stretched position is held for a programmed length of time. In a preferred embodiment, the control apparatus further includes measuring means for determining an amount of stretch measurement which is indicative of the amount of stretch achieved by the user in the stretched position. The measuring means may use any suitable sensor arrangement such as infra red and/or optic sensors, accelerometers and the like. The output device may be configured to display one or more amount of stretch measurements and the memory component may be configured to retain one or more amount of stretch measurements. The control apparatus may be programmed to guide a user through a stretching routine which facilitates the use of Proprioceptive Neuromuscular Facilitation (PNF) of the muscle fibres to increase subsequent stretches. Steps in the stretching routine may include but are not limited to assuming a stretched position, contracting stretched muscles for a pre-defined duration, assuming a deeper stretched position, holding a stretched position and exiting the stretched position. Preferably, the control apparatus is also programmable for use in "manual" mode in which the user is not required to follow a pre-programmed stretching routine. Preferably, the control panel also provides visual guidance for the user, by way of written or diagrammatic instructions. It is also desirable for the control apparatus to provide audible output with adjustable volume control, to guide the user in correct use of the machine. Alternatively or additionally, visual cues such as a sequence of light emitting diodes (LEDs) may be used to assist the user prior to, during and after use of the exercise machine.

Brief Description of the Drawings The present invention will now be described in greater detail with reference to the accompanying drawings. It is to be understood that the particularity of the accompanying drawings and the discussion which follows does not supersede the generality of the preceding description of the invention. Figure 1A shows an exercise machine according to an embodiment of the invention which is suitable for stretching leg muscles by performing a front stretch. Figure 1 B shows the exercise machine of Figure 1 A in an alternative arrangement which is suitable for stretching leg muscles by performing a side or adductor stretch. Figure 1C shows the exercise machine of Figure 1 A in an alternative arrangement in which the guide means are on a slight decline. Figure 1 D shows the exercise machine of Figure 1 B in an alternative arrangement in which the guide means are on a slight incline to accommodate a "hyper-stretch". It can also be used to aid the user in the case of weakness or injury, or assist elderly or other users wanting to initiate, target or exercise different muscle groups. Figure 2 shows a pulley and cable system suitable for use with an embodiment of the invention. Figure 3 shows a detent and roller arrangement suitable for use with the exercise machine illustrated in any one of Figures 1 A to 1 D. Figure 4 shows an end means suitable for use with the exercise machine illustrated in any one of Figures 1A to 1 D. Figure 5 shows a pin system suitable for facilitating different levels of "splay" of the handles of the exercise machine of any one of Figures 1 A to 1 D. Figure 6 shows an example of a timer console suitable for use with an embodiment of the invention. Figure 7 is an example set of diagrammatic instructions for basic stretch options for use with a timer console such as that of Figure 6.

Detailed Description Referring firstly to Figures 1 A to 1 D, an exercise machine 1 is shown with a base 2, a pair of foot supports 4a and 4b and guide means 6a and 6b along which the foot supports slide. Adjustable body support means is provided in the form of handles 8a and 8b. To use the exercise machine, a user places a foot on each of the pair of foot supports 4a and 4b and slides the foot supports apart to assume a position in which the leg muscles are stretched. To exit the stretched position, the user contracts the leg muscles and slides the foot supports 4a, b together. Throughout this process, handles 8a, b are used to provide stability to the user. To assist in exiting the stretched position, the user may transfer part of their body weight from their legs to their arms using the handles to reduce the initial muscular contraction required to slide the foot supports together. Base 2 provides a firm footing for the exercise machine 1 and is provided by a steel plate which supports the combined mass of the machine and the user. Any suitable base shape and/or material may be used. Preferably, a heavy material such as steel is used to prevent accidental movement of the exercise machine. Alternatively or additionally, the base may be anchored to the floor or other supporting surface on which the exercise machine is used by bolts or other fastening means to ensure stability during use. Foot supports 4a,4b slide away from and toward each other along guide means 6a, 6b. Preferably, this is facilitated by rollers (not shown) attached to the underside of the foot supports and which are configured to ride along tracks (not shown) formed in the top of the corresponding guide means. Alternatively or additionally, one or more rollers may be attached to each of foot supports 4a,4b such as by way of a bracket or arm 5, with the one or more rollers configured to roll along tracks in the underside of the corresponding guide means. Preferably, sliding movement of the foot supports 4a,4b along guide means 6a, b is as close to "frictionless" as is possible. Since there is little or no friction or resistance to sliding of the foot supports 4a,4b, the sliding is controlled to a large degree by the user's own leg muscles, primarily the thigh adductors, abductors and hamstrings, thereby strengthening those muscles as well as stretching them during use of the machine. The muscles of the lower leg including the calf may also be employed, in addition to core stabilising muscles of the torso. The foot supports 4a, b are preferably linked in such away that they remain equidistant from a starting point or "home position" during use of the machine. In the embodiment illustrated, this is achieved using a pulley and cable system such as the one shown in Figure 2. Foot supports 4a, b are attached at fixed locations to a continuous cable 7 so that sliding foot support 4a away from the home position along guide means 6a causes the cable to move around the pulleys in such a way that foot support 4b also slides away from the home position, along guide means 6b by the same amount. This ensures that an evenly balanced stretch is experienced by the user. In a preferred embodiment, foot supports 4a, b are biased using a spring (not shown) or other suitable means so that they retract automatically to the home position in the absence of a sliding force being applied by the user. The strength of the spring may be varied, depending on the desired force with which the foot supports retract to the home position. A weaker spring may be used for machines designed to develop muscle strength as well as flexibility in which the user must use their leg muscles to supply most of the sliding force which slides the foot supports back to the home position when the machine is in use. In such an arrangement, the spring bias may be suitable for retaining the foot supports at the home position when the machine is not in use (i.e. when the foot supports are not supporting the mass of the user). It is desirable that the biasing means or "self retraction" mechanism urges the foot supports to return to the home position regardless of the attitude or angular disposition of the guide means. Accordingly, in embodiments where self-retraction is incorporated into an exercise machine with the guide means set on an incline or decline, the foot supports must be retained on the surface of the guide means in such a way that they do not lift off or "de-rail" from the guide means when they retract to the home position. This may be achieved by retaining the foot supports in tracks along the guide means, or retaining rollers on which the foot supports slide in tracks along the guide means. Alternatively, rollers or bearings may be provided both above and below the guide means to ensure that the foot support does not leave the guide means. The foot supports may retract to the home position with a significant amount of force, depending on the strength of the spring. Accordingly, as a safety precaution, it is desirable that a brake or other suitable stopping means is included to stop the foot supports when they reach the home position. It is also desirable that the stopping means prevents the foot supports from sliding out from under the user when the user first places their feet on the foot supports. Inclusion of a stopping means also minimises the possibility of injury to the user or another person as a result of the foot supports "slamming" together, jamming a finger, toe or other body part. The stopping means may be provided in any suitable form. In one embodiment the "stoping means" includes a detent and roller brake arrangement such as the one illustrated in Figure 3. Figure 3 shows a detent and roller arrangement in which a brake roller 37 is attached to one of the foot supports 4a using a brake arm 29. When the biasing spring causes the foot support 4a to retract to the home position, brake roller 37 becomes seated in detent 38. This prevents the foot support from sliding along the guide means until the user applies a sufficient sliding force to the foot support 4a to remove the brake roller from the detent and begin sliding. Preferably, the detent is angled in such a way that the sliding force required to remove the brake roller from the detent can be readily supplied by the user whilst being sufficient to prevent accidental removal of the brake roller from the detent. This brake is adjustable to accommodate various weights and forces applied by different users, or during different exercises. In an embodiment where linking means links the movement of the two foot supports, a single stopping means can prevent both of the foot supports from moving. However, it is to be understood that a stopping means such as the detent and roller arrangement of Figure 3 could be provided for each of the foot supports and may be particularly useful in an embodiment in which movement of the pair of foot supports is not linked. The exercise machine of Figures 1A to 1 D also show pairs of holes 15 along the length of guide means 6b. These holes are configured to receive an end means such as the abutment member 80 illustrated in Figure 4. The end means shortens the distance over which foot supports 4a, b slide. The abutment member has protrusions 82 which, when the abutment member is in use, sit in a pair of holes 15. Abutment member 80 also has web portion 84 with which foot support 4b may abut. The pair of holes used is selected based on the desired length of the guide means along which the foot supports should slide. Pairs of holes 15 are preferably spaced along guide means 6b at less than or equal to 150mm intervals, beginning 250mm from turret 10. However, this spacing is an example only and it is to be understood that other spacings may be suitable. Each of these sets of holes is numbered to ensure ease and safety of use and repeatability when desired. For beginners or less flexible users, the abutment member 80 should be retained in a pair of holes 15 which is closer to turret 10 to prevent the foot supports from sliding further apart than the user's flexibility can accommodate. As the user trains using the exercise machine and their flexibility improves, the user will be able to slide the foot supports further apart. To accommodate and challenge this increase in flexibility, the abutment member can be moved into a pair of holes which is further away from the home position. The end means can also be used to shorten the effective length of the guide means to accommodate shorter users or users with shorter legs. However, the primary purpose of the end means is as a safety feature to minimise injury due to overstretching. In an embodiment where movement of the pair of foot supports is linked, it is not necessary to provide an end means on both of guide means 6a, b. However, pairs of holes may be provided along both guide means 6a, b in an embodiment of the exercise machine in which movement of the foot supports is not linked. Particularly flexible users are unlikely to require use of the end means. When not in use, the end means illustrated in the drawings may be stored safely in the pair of holes 15 which is furthest from the turret. The abutment member is preferably retained by use of a retractable cable or curly cord. Such retraction does not affect use of the machine and is advantageous because it does not interfere with moving parts during normal use. Foot supports 4a, b have a rubberised surface which provides added grip and cushioning for the user and which may decrease stress on the user's joints. Figures 1 A to 1 D also show a raised lip 25 along the inside and outside edge of each of foot supports 4a, b. These raised lips prevent the user's foot from sliding or being drawn along the foot supports toward the home position. This is particularly useful for users of the exercise machine with excellent flexibility who may perform a "hyper-stretch" where the body's tendency is to draw the feet together when the legs are stretched to their maximum range of motion. The raised lip 25 on the foot supports may take any suitable form, such as a straight inclined portion, a ridge, or a curved portion of gradually increasing thickness. The raised lip may be any suitable thickness, however a lip-thickness of 10mm relative to the surface of the foot supports has been found suitable. Preferably, the foot supports are of a size and shape which supports the weight of the user and is contactable by the whole of the user's foot to provide sufficient stability during use of the machine. It is also desirable to limit the amount of lateral rocking or "play" exhibited by the foot supports as they slide away from and toward each other along the guide means. Such play can be limited in one form by increasing the width of the guide means along which the foot supports slide. The foot supports may also be adjusted to accommodate a range of foot orientations where the foot support is parallel with the ground, inclined toward the base or inclined away from the base. Alternatively or additionally, the foot supports may be adjusted to be in line with or perpendicular to the guide means or at any angle therebetween to permit flexion or extension at the ankle and provide more comfortable stretching. Orientation of each of the pair of foot supports is preferably independently adjustable to accommodate natural orientation of the feet as may be required in the front stretch position or, for example, during stretching of the hamstrings, quadriceps or hip flexors. Handles 8a, b are attached to top plate 14 which is adjustably connected to base 2. In one embodiment, this is achieved using a large circular slide-plate and bush arrangement between the top plate 14 and the base 2. Alternatively, four rollers may be positioned between the top plate and the base and spaced at 90 degree intervals around the turret 10 to facilitate rotation of the top plate relative to the base. In the embodiment of Figures 1A and 1C, the body support means is positioned with handles 8a, b arranged substantially parallel with guide means 6a, b. In this orientation, the handles are comfortably positioned for the user to grasp when in a front stretch position and facing along the guide means 6a or 6b. In the embodiment illustrated in Figures 1 B and 1 D, the body support means is positioned with handles 8a, b arranged substantially at right angles with guide means 6a, b. In this orientation, the handles are comfortably positioned for the user to grasp when in a side or adductor stretch position and facing away from the guide means 6a, b. Handles 8a, b are integral with vertical arms 22a, b which in turn sit partially within sleeve 24a, b. Sleeves 24a, b each have a hole through which a pin 28 is inserted and each of vertical arms 22a, b has a plurality of holes along its length which can be aligned with the hole in the corresponding sleeve to facilitate adjustment of the height of the handles. This enables the machine 1 to be adapted for comfortable and safe use by different users. Preferably, vertical arms 22a, b are supported by an internal spring, piston or strut (not shown) inside each of sleeves 24a, b. The internal springs assist in height adjustment of the arms and provide an additional safety feature, decelerating the vertical arms if dropped into the sleeves. It is preferred that the handles 8a, b also permit a degree of "splay" or angulation away from the turret to accommodate users with longer arms, broad shoulders or the like. Adjustable splay may be achieved using a pin-system such as the one illustrated in Figure 5. Sleeve 24a is connected to top plate 14 by way of bracket 86 having a hole through which locking pin 87 is inserted. The hole in bracket 86 is aligned with one of a plurality of holes 85 arranged along a curve in a corresponding side of top plate 14 and the locking pin 87 is inserted therethrough to retain the handles in a position with a predetermined degree of splay. The splay can then be adjusted by removing locking pin 87, aligning the hole in bracket 86 with a suitable hole 85 and re-inserting the locking pin. The end of each of the guide means 6a, b is retained on end supports 16a,b respectively, using a pin system. As can be seen in Figures 1A to 1 D, a plurality of holes are provided along the height of end supports 16a,b. Pins 18a,b are used to retain the end of each guide means 6a, b at a particular height on the end support. The height of the end of each of the guide means can be adjusted by aligning the hole in the end of guide means 6a, b with one of the plurality of holes in end supports 16a,b respectively. Therefore, the user can adjust the attitude of the guide means enabling exercise machine 1 to challenge users who have different levels of flexibility. Preferably, each of the adjustment holes is numbered, e.g. 0,1 ,2,3... It is desirable that the numbering system indicates whether the guide means are adjusted on an incline or decline (i.e. above or below horizontal). For example, numbers corresponding to adjustment of the guide means on a decline (below horizontal) may be shown in red; numbers corresponding to adjustment of the guide means on an incline (above horizontal) may be shown in black, to ensure ease of use and safety. Alternatively, positive/negative numbering systems or any other suitable identification system may be used. In Figures 1A and 1 B, guide means 6a, b are shown in rectilinear configuration so that when a flexible user stretches their leg muscles to their maximum range of motion, they form a straight (180 degree) angle. The exercise machine illustrated in Figure 1 C shows the embodiment of Figure 1A, with the handles arranged for use in the front stretch position, but with guide means 6a, b on a slight decline from the turret 10 to accommodate an obtuse angle between the user's legs. This is achieved by lowering the height at which each of guide means 6a, b is retained on end supports 16a,b respectively. This adjustment in the attitude of the guide means can be achieved with the handles in any orientation. The angle illustrated in Figure 1C may be suitable for a user with moderate to good flexibility. This configuration also assists the user in adopting the principles of Proprioceptive Neuromuscular Facilitation (PNF) as the user will need to contract the leg muscles being stretched in order to maintain the stretched position. The exercise machine illustrated in Figure 1 D shows the embodiment of

Figure 1 B, with the handles arranged for use in the side stretch position and with guide means 6a, b on a slight incline from the turret to accommodate a reflex angle between the user's legs when stretched to their maximum range of motion. This is achieved by increasing the level at which guide means 6a, b are retained on end supports 16a,b respectively. This angle is suitable primarily for users with excellent flexibility enabling them to perform a "hyper-stretch". It can also be used to aid the user in the case of weakness or injury, or assist elderly or other users wanting to initiate, target or exercise different muscle groups. Preferably, pins used to accommodate adjustment of the height and splay of handles, attitude of the guide means and the like are of the "pull-to- adjust" and "release-to-lock" kind which can be withdrawn from their respective holes to a degree which facilitates insertion at a new level, but which cannot be dislodged entirely thus preventing accidental loss or displacement of pins. It is also preferred that the adjustment holes are numbered so that users can ensure the machine is correctly adjusted each time it is used. Any suitable marking or numbering system may be used to achieve this. In one embodiment, an outer shaft is provided with a hole for a pin and a second hole is provided adjacent the pin hole. In this embodiment, the inner shaft, having a plurality of holes along its length to receive the adjustment pin, also includes a number adjacent each hole which is visible through the second hole in the outer shaft when the pin is in place, correctly identifying the adjustment level. Other indicators may be used as an alternative, as may be identified by the skilled addressee. Using exercise machine 1 in the manner described, the user experiences a level of stretch corresponding to a maximum range of motion of the leg muscles, and holds the stretch. It is preferred that whilst in the stretched position, the user contracts the muscles being stretched (e.g. the thigh adductors when assuming a side stretch) for a period of time to invoke a reflex triggered by the golgi tendon organs. It is believed that this has the effect of "re- setting" the stretch reflex in the stretched muscle and allows a slightly greater range of muscle motion when the stretch is reapplied. This exercise of stretching and contracting the stretched muscles will hereinafter be referred to as a "stretch-and-contract" exercise. Preferably, the user performs the stretch- and-contract exercise at least 2 or 3 times, employing the Proprioceptive Neuromuscular Facilitation (PNF) method to increase the range of motion exhibited by the muscles being stretched. A final stretch using the maximum range of motion may then be applied and held without contracting the stretched muscles, before the user exits the stretched position. The exercise machine illustrated in Figures 1A to 1 D also includes control apparatus which enables a user to perform a programmed stretching routine consisting of a sequence of stretch-and-contract and hold/relax exercises. An example of a console 20 for providing input and output from the control apparatus is shown in Figure 6. Console 20 presents information and/or instructions which may be written or diagrammatic for using the exercise machine and facilitates input to the control apparatus. An example of diagrammatic basic stretch options is illustrated in Figure 7. Logic and electronic circuitry for implementing the control apparatus can be realised in a number of ways known to the skilled addressee as can sensors and circuitry for determining the amount of stretch achieved by the user. Such sensors may include optic and infra red sensors, accelerometers and the like. In one example embodiment the sensor incorporates a radar device having fixed location, and using one of the foot supports as a reference point for measurement. As the foot support moves, the reference point moves and is detected by the radar sensor. The sensor is calibrated so as to display the distance moved in millimetres, although other dimensions such as inches or centimetres may be used as an alternative. In this example embodiment, the measurement displayed is actually the distance between the 2 foot supports. However, in other embodiments the display may indicate the distance moved by one foot support or by both foot supports but displayed separately. Preferably, the control apparatus is pre-programmed with one or more stretching programs consisting of stretch-and-contract exercises and the user can execute, program, store and/or delete additional stretching programs. A "Program" button may be provided and pressed by the user to toggle through pre-programmed stretching programs. Preferably these are "PNF mode" stretching programs although other modes of stretching programs may also be pre-programmed into the control apparatus. The user may also retain one or more pre-defined programs entered in "manual" mode. Console 20 includes four display regions, 30, 40, 50, and 60. Display regions 30 and 40 enable the user to enter parameters for use in "Proprioceptive Neuromuscular Facilitation (PNF)" stretching mode or "manual" stretching mode respectively. Display region 50 includes four light emitting diodes (LEDs) which are illuminated at different times to indicate whether the user should be assuming, holding or exiting the stretched position or contracting the stretched muscles. Any suitable illumination means may be used as an alternative. To use the exercise machine in "PNF" mode, buttons in display region 30 are employed and the user performs the following steps.

1. Press, "start" button 32 to commence the stretching routine. A 5 second period will follow in which the user will stretch to the first stretched position. During this time, "stretch" LED 51 will illuminate.

2. An audible cue will then sound for 5-15 seconds during which the user holds the first stretched position and contracts the stretched muscles. Preferably, this audible cue is accompanied by illumination of "contract" LED 52. The sound level of the audible cue can be adjusted using volume adjust controls 63. The "contract" duration may be adjusted according to the user's preference when the control apparatus is programmed with a stretching routine.

3. Once the audible cue and/or illumination of "contract" LED 52 has expired, a 5 second period will follow in which the user moves deeper into the stretch (the second stretched position). During this time, "stretch" LED 51 will illuminate. 6. An audible cue will sound again for 5-15 seconds during which the user holds and contracts the stretched muscles in the second stretched position. Preferably, the audible cue is accompanied by illumination of "contract" LED 52.

7. Once the audible cue and/or illumination of "contract" LED 52 has expired, a 5 second period will follow in which the user moves deeper into the stretch (the third stretched position). During this time, "stretch" LED 51 will illuminate.

8. An audible cue will sound again for 5-15 seconds during which the user holds and contracts the stretched muscles in the third stretched position. Preferably, the audible cue is accompanied by illumination of "contract" LED 52.

9. Once the audible cue and/or illumination of "contract" LED 52 has expired, a 5 second period will follow in which the user moves into the final (fourth) stretched position. During this time, "stretch" LED 51 will illuminate. 10. An audible cue will then sound for 15-60 seconds (adjustable according to the user's preference) signalling for the user to relax into the stretch with no contraction. Preferably, the audible cue is accompanied by illumination of "hold" LED 53. At the end of the "hold" period, the PNF routine is complete. 11. An audible cue will then sound for 3 seconds, preferably accompanied by illumination of "end of routine" LED 54 to indicate that the user may now exit the final (fourth) stretched position. Progress meter 61 will display a measurement of the amount of stretch achieved by the user in the final stretched position. This value will be retained until such time as reset button 62 or start button 32 or 42 (PNF or Manual mode) is depressed.

To use the stretching device in "manual" mode, buttons in display region 40 are used. The user may set up an individual timing sequence for a simple stretch and hold routine using the following steps. 1. Press "start" button 42 to commence the stretching routine. A 5 second period will follow in which the user stretches into the first position. During this time, "stretch" LED 51 will illuminate. 2. An audible cue will then sound for a pre-programmed length of time adjustable between 5 and 60 seconds signalling for the user to hold the stretch. Preferably this is accompanied by illumination of "hold" LED 53. At the end of the "hold" period, the "manual" routine is complete. 3. An audible cue will then sound for 3 seconds, preferably accompanied by illumination of "end of routine" LED 54 to indicate that the user may now exit the stretched position. Progress meter 61 will display a measurement of the amount of stretch achieved by the user. This value will be retained until such time as reset button 62 or start button 32 or 42 (PNF or manual mode) is depressed. The audible cues may include beeps, tones or a pre-recorded voice providing verbal instructions to "assume a stretched position", "hold the stretched position", "contract the stretched muscles" and the like. The audible output level may be adjusted using volume adjust controls 63. In an alternative arrangement where foot supports 2 are not linked, two numerical displays may be included to show different numerical values indicating respective distances travelled by the foot supports 2. The durations and ordering of "stretch-and-contract" exercises provided in the preceding description are examples only and may be adjusted as necessary. Advantageously, the present invention can be used to improve flexibility as well as strength. Accordingly, the present invention may be used to improve general health and fitness and may also be used to train high level athletes such as those involved in dancing, martial arts, gymnastics, football and the like. The present invention is also suitable for use in rehabilitation. The exercise machine is adaptable for use by users of different stature, age, strength and proportions, and can be adjusted to comfortably stabilise a user when using the exercise machine to perform a front stretch or a side or adductor stretch. It is to be understood that the durations, visual and audible cues and other aspects of the stretching routine are examples only, and various modifications, additions and/or alterations may be made to the parts previously described without departing from the ambit of the present invention as defined in the claims appended hereto.

Claims

1. An exercise machine including: a base; a pair of foot supports; guide means to accommodate sliding of the pair of foot supports away from and toward each other; and body support means, adjustable relative to the guide means to stabilise a user facing in one of a plurality of directions when using the exercise machine; wherein a user places a foot on each of the pair of foot supports and slides the foot supports apart to assume a stretched position in which leg muscles are stretched, and exits the stretched position by contracting the leg muscles to slide the foot supports together.

2. An exercise machine according to claim 1 wherein the plurality of directions includes a first direction in which the user faces along the guide means, a second direction in which the user faces away from the guide means and any direction between the first and second directions.

3. An exercise machine according to claim 1 wherein the body support means includes a pair of handles positioned either side of the user.

4. An exercise machine according to any one of the preceding claims wherein the guide means are adjustable relative to the horizontal to accommodate inclined, straight or declined sliding of the foot supports.

5. An exercise machine according to any one of the preceding claims further including biasing means for returning the foot supports to a home position.

6. An exercise machine according to any one of the preceding claims further including stopping means to preclude movement of at least one of the foot supports until a suitable force has been applied.

7. An exercise machine according to claim 6 wherein the stopping means includes a detent and roller arrangement.

8. An exercise machine according to any one of the preceding claims further including linking means linking the two foot supports so that they move equidistantly from a starting location.

9. An exercise machine according to any one of the preceding claims further including end means to limit the distance over which one or both of the foot supports slide.

10. An exercise machine according to any one of the preceding claims further including foot retaining means on each of the foot supports.

11. An exercise machine according to any one of the preceding claims further including height adjustment means for adjusting the height of the body support means.

12. An exercise machine according to claim 3 further including splay adjustment means to adjust an amount of splay of the handles.

13. An exercise machine according to any one of the preceding claims wherein the foot supports are adjustable to accommodate at least the following orientations in which one or both of the foot supports is: (a) parallel with the ground;

(b) inclined toward the base; or

(c) inclined away from the base.

14. An exercise machine according to any one of the preceding claims wherein the foot supports- are adjustable to accommodate positioning of the user's foot in at least the following orientations:

(a) in line with the guide means; or

(b) perpendicular to the guide means; or

(c) at an angle between (a) and (b).

15. An exercise machine according to any one of the preceding claims further including control apparatus having a timing device, input and output means and a memory component, the control apparatus being programmable to indicate to the user to:

(i) assume the stretched position; (ii) hold the stretched position; and (iii) exit the stretched position.

16. An exercise machine according to claim 15 wherein the control apparatus is programmable to indicate to the user to contract the stretched muscles for a period of time.

17. An exercise machine according to claim 15 or claim 16 wherein the control apparatus is programmable with a stretching routine in which the leg muscles are stretched and the stretched position is held for a pre-determined length of time.

18. An exercise machine according to any one of claims 15 to 17 wherein: the control apparatus further includes measuring means for determining an amount of stretch measurement; and the output device displays one or more amount of stretch measurements.

19. An exercise machine according to claim 18 further including a memory component configured to retain one or more amount of stretch measurements.

20. An exercise machine according to any one of claims 15 to 19 wherein the control apparatus is programmed to instruct the user to execute a stretching routine which uses proprioceptive neuromuscular facilitation of muscle fibres to increase subsequent stretches by performing steps including but not limited to:

(i) assuming the stretched position;

(ii) contracting the stretched muscles for a pre-defined duration;

(iii) assuming a deeper stretched position; and

(iv) exiting the deeper stretched position.