Exercise machine with movable user support

An exercise machine with a two directional pivoting user support assembly has a user support or platform which supports the user and pivots about a first pivot axis during an exercise movement, and is also pivotable about at least one second pivot axis to involve the user's core muscles in balancing and maintaining the user support in a stable position. A manually operable locking device with a simple flip switch lever is provided for selectively locking the user support against rotation about the second pivot axis, so that the user can easily chose whether to perform the exercise with a stable support or to add a level of difficulty by using the unstable seat mode and exercising core muscles during the exercise.

BACKGROUND

1. Field of the Invention

This invention relates generally to exercise machines and is particularly concerned with exercise machines having two directional pivoting user supports.

2. Related Art

User supports which support an exerciser in seated, prone, kneeling, or upright positions while performing an exercise on an exercise machine are known. Such supports may be stationary, or may be designed to rock during an exercise. In a rotary torso exercise machine, a user support is mounted for rotation about a vertical axis and the user rotates their lower torso relative to their upper torso to the right and left of a central position.

Some user supports are rotatable about a second pivot axis during exercise so as to exercise a user's core muscles, for example the abdominal exercise machine described in U.S. Pat. No. 8,172,732 of Webber et al.

SUMMARY

In one aspect, an exercise machine with a two directional pivoting user support assembly is provided, in which a user support or platform which supports the user pivots about a first pivot axis during an exercise movement, and is also pivotable about at least one second pivot axis to involve the user's core muscles in balancing and maintaining the user support in a stable position. Thus, the user support is unstable about the second pivot axis. In one embodiment, a manually operable locking device is provided for releasably locking the user support against rotation about the second pivot axis, so that the user can easily chose whether to lock the user support and perform the exercise with a stable support or to add a level of difficulty by releasing the lock and allowing the seat to rock in an unstable seat mode, requiring the exerciser to use core muscles during the exercise to hold the support in a level position.

In one embodiment, the user support assembly comprises a base which is rotatable about the first pivot axis, and the user support is pivotally mounted on the base for rotation about at least one second pivot axis non-parallel to the first pivot axis, adding instability to the user support or platform during the exercises. A manually operable locking mechanism is provided between the base and user support, comprising a first lock part having an opening and a second part comprising a releasable locking pin movable between a locked position engaging the opening to prevent rotation of the user support about the second pivot axis and an unlocked position retracted from the opening. In one embodiment, the first lock part may be a lock plate or bracket located under the user support and the second part is mounted on the base. A manually engageable lock tab or switch lever is rotatable between first and second positions to extend and retract the locking pin.

The user support may be designed for supporting a user in a seated or kneeling position while performing an exercise on an exercise machine, and may be pivotally mounted on the base for side to side pivoting motion about a pivot axis beneath the user support platform, or for side to side tilting or swiveling motion about a pivot axis extending transversely through the user support. In one embodiment, a pair of bumper pads may be provided on the base on opposite sides of the pivot axis for engaging the user support pad to limit rotation of the user support pad in each direction to a predetermined angular range.

In one embodiment, an unstable, tiltable user support is designed for supporting a user in a kneeling position, and may be provided on a rotary torso exercise machine. The rotary torso machine in one embodiment comprises a main frame, a user lower torso support rotatably mounted on the frame for rotation about a first, vertical axis, and an upper torso support mounted on the frame for supporting the upper torso in a fixed position while the lower torso is rotated. The lower torso support comprises the unstable user support and is also pivotally mounted for limited rotation about a horizontal pivot axis so that the user has to balance the support while performing the rotating or twisting exercise motion. This produces a greater engagement of the user's core muscles in maintaining the user support in a horizontal plane while rotating their lower torso about a central vertical axis. The addition of the releasable locking mechanism allows the user to select whether or not to use core muscles during the exercise.

In another embodiment, the exercise machine is an abdominal exercise machine, and the base is pivoted on a frame for rotation about the first pivot axis, and the user support is pivotally mounted on the base for rotation about the second pivot axis transverse to the seat in which the user's lower torso pivots from side to side from a central position. An exercise arm is pivotally mounted on the frame for rotation about a third pivot axis parallel to the first pivot axis, and a connecting link is provided between the exercise arm and user support base so that movement of the exercise arm automatically moves the user support in a first direction to perform an abdominal exercise. In this embodiment, the locking mechanism is provided between the base and user support seat and can be controlled by the user to lock the user support seat relative to the base so that exercises are performed on a stable user support. When the mechanism is unlocked, the user support is freely rotatable about the second pivot axis during the abdominal exercise, and this movement is controlled by the user using core muscles to maintain the user support in a steady position.

In another embodiment, an unstable user support may be provided on any one of a plurality of different upper torso machines or other exercise machines to support a user in an exercise position while performing an exercise, so the user employs core muscles to hold the seat level while exercising selected muscles. The unstable user support may be provided on an arm exercise machine, a shoulder press exercise machine, a chest exercise machine, a pec fly exercise machine, or a seated mid row exercise machine, or other types of exercise machine in which the user is supported in a seated, kneeling, or other exercise position. Unstable user supports may also be designed in a similar way for supporting users in other exercise positions in other alternative embodiments, such as prone or standing positions.

The releasable locking mechanism or device is easily operated manually by the user for movement between the locked and unlocked positions when positioned on or off the user support, simply by turning or flipping a lock control tab or switch lever between first and second positions with their finger or thumb.

DETAILED DESCRIPTION

Certain embodiments as disclosed herein provide for an exercise machine with a two directional pivoting user support assembly, in which a user support or platform which supports the user in an exercise position pivots about a first pivot axis during an exercise movement, and is also pivotable about at least one second pivot axis to involve the user's core muscles in balancing and maintaining the user support in a stable position. Thus, the user support is unstable about the second pivot axis. In one embodiment, a manually operable locking device is provided for releasably locking the user support against rotation about the second pivot axis, so that the user can easily chose whether to perform the exercise with a stable support or to add a level of difficulty by using the unstable seat mode and exercising core muscles during the exercise.

After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation.

FIGS. 1A to 2illustrate a first embodiment of an exercise machine10incorporating a pivoting user support assembly12rotatable about two or more axes, whileFIGS. 3 to 10illustrate a second embodiment of the user support assembly12A which may replace assembly12of the machine ofFIGS. 1A to 2. User support assembly12A is modified to incorporate a manually operable locking device or mechanism14, but is otherwise identical to user support assembly12ofFIGS. 1A to 2. Locking mechanism14is configured to releasably lock user support or platform15against rotation about the second pivot axis, as described in more detail below. One embodiment of locking mechanism14is illustrated in more detail inFIGS. 11 to 16. However, other locking devices or mechanism may be used in alternative embodiments.

Exercise machine10ofFIGS. 1A to 1Cis a rotary torso machine. However, locking mechanism14may be incorporated in other exercise machines having pivoting user supports with more than one direction of rotation in other embodiments, such as an arm exercise machine, a shoulder press exercise machine, a chest exercise machine, a pec fly exercise machine, a seated mid row exercise machine, or an abdominal exercise machine as illustrated inFIGS. 17 to 22, or other types of exercise machine with rocking or pivoting user supports in which the user is supported in a seated or kneeling position.

The user support assembly12or12A is designed to support a user in a kneeling position, but it should be understood that the device may alternatively be designed for supporting users in different positions, such as seated positions, for example as shown in the second embodiment described below in connection withFIGS. 17 to 22. The kneeling user support assembly12or12A may also be incorporated on other exercise machines in which a user performs an exercise in a kneeling position.

Apart from the locking mechanism14, the user support assembly ofFIGS. 3 to 10is identical to the user support assembly ofFIGS. 1A-1C and 2as described in detail in co-pending application Ser. No. 13/491,256 filed on Jun. 7, 2012, the contents of which are incorporated herein by reference. Unstable user support assembly12basically comprises a base28and user support or platform15mounted on base28via support post60and support bracket21secured to the upper end of post60, as best illustrated inFIG. 2. Base28is rotatably mounted on stationary frame member or plate55for rotation about a first, vertical pivot axis19(seeFIGS. 1B and 1C). A kneeling pad115and side support pads16are mounted on user support15as illustrated inFIGS. 1A to 1C. The side support pads16are mounted on side support plates17on opposite side ends of the user support platform15. User support platform15is rotatably mounted on bracket21via a pivot connection18for rotation about a second, horizontal pivot axis20beneath platform15which is aligned with the direction of the user's knees when kneeling on the user support and parallel to the plane of platform15. As best illustrated inFIG. 2, the pivot connection18comprises a pivot pin22secured between end plates or portions24of U-shaped bracket21and rotatably engaged in pivot sleeve25secured to the lower surface of user support platform15. A pair of bumper pads26which may be of rubber or the like are secured to the mounting bracket21on opposite sides of the pivot axis, as best illustrated inFIG. 2.

Mounting bracket21is designed for attaching to a user support mounting post or other mounting device on an exercise machine, in place of a conventional, stable user support, such as the user support of a rotary torso machine or any other exercise machine designed for users to perform exercises in a kneeling position. In the illustrated embodiment, mounting bracket21is secured to base28via mounting post60. An angled guide121with a notch23for receiving a rotational range adjust lever29projects from the forward end of user support platform15, as illustrated inFIGS. 1A, 1B and 2, but guide121may be eliminated in alternative embodiments of the unstable user support.

The user support platform15of the unstable user support device12can pivot from side to side relative to support bracket21about the horizontal pivot axis20by an amount determined by the height of rubber bumper pads or stops26. Modified user support device12A can also pivot or rock from side to side in the same manner when the manually operable locking mechanism14is in the unlocked condition.FIG. 10illustrates the right and left tilted end positions of the user support platform15in dotted outline, with reference numbers ending in an R representing rotation to the right (clockwise as viewed inFIG. 10) and reference numbers ending in an L representing rotation to the left (anti-clockwise as viewed inFIG. 10). Thus, the user support platform in the illustrated embodiment has a degree of instability of five degrees off horizontal from side to side. In the illustrated embodiment, the user support can pivot down to the left or the right about axis20through an angle of 0 to around 5 degrees in either direction before contacting a bumper pad or stop26, as illustrated in dotted line inFIG. 10. When locking mechanism14is in the unlocked or rocking position, a user kneeling on the user support must use core muscles in order to maintain the platform in a stable, horizontal position while performing an exercise.FIGS. 3 to 9illustrate a balanced, centered or 0 degrees orientation of the user support platform15in which the platform does not contact either bumper pad, and the platform may be locked in this position by locking mechanism14if desired by the user, as described in more detail below.

Although the user support platform tilts from side to side about a horizontal pivot axis extending in a front to rear direction in the illustrated embodiments, other embodiments may have different pivot joints between platform15and mounting bracket21to allow pivoting about different pivot axes or in different planes, for example a universal joint to provide instability in all directions, or a horizontal pivot axis perpendicular to axis20to permit pivoting down at the front and rear of the platform15. Additionally, although the user support platform is oriented horizontally in the illustrated embodiment, it may be slightly tilted or angled downwards or upwards when mounted on an exercise machine support structure in other embodiments, depending on the type of exercise. In such alternatives, the axis20is not horizontal but extends parallel to the plane of the user support platform, and the platform still tilts or rocks from side to side about the axis20. In each of these alternatives, the platform of user support assembly12A may be locked in a single, central position to prevent tilting if desired by the user.

In the illustrated embodiment ofFIGS. 1A to 2, the user support platform pivots freely up and down between zero and five degrees on each side about pivot axis20. In the modified user support assembly ofFIGS. 3 to 10, releasable locking mechanism14selectively secures user support platform15in the horizontal orientation ofFIG. 2if a user wishes to perform the exercise without core muscle involvement. When locking mechanism14is in the locked position ofFIGS. 3 and 4, the user support platform15rotates only about the vertical axis18during a rotary torso exercise.

FIGS. 11 to 16illustrate one embodiment of manually operable locking mechanism14between base28and user support15in more detail. However, it will be understood that different locking mechanisms may be used in alternative embodiments to releasably lock the user support to base28. As illustrated in the exploded view ofFIG. 11, the locking mechanism or device14basically comprises a first part or lock plate110having an opening112and a mounting portion114, and a second part135including a lock pin housing116in which plunger or lock pin118is movably mounted. Housing116is mounted on mounting post120from which bumper plate122extends in a radial direction. Oppositely directed bumper pads124are secured to bumper plate122. Switch lever body or sleeve125has a first end telescopically and rotatably engaged over the end of lock pin housing116, as best illustrated inFIGS. 16A and 16B. A switch lever or manually operable lock release tab126is secured to rotatable sleeve125. Plunger or lock pin118is secured to cam member127at the opposite end of switch lever body or sleeve125, as best illustrated inFIGS. 16A and 16B, and extends from cam member127through a bore in housing116. Return spring129urges lock pin118towards the locked position, as described in more detail below. A stop plate128secured to sleeve125engages one of the pads124in the unlocked position ofFIGS. 4 and 10and the oppositely directed pad124in the locked position ofFIGS. 5, 6 and 15. In the illustrated embodiment, the first part or lock plate110is secured to the user support platform15while the support post120of the second part is secured to the user support base28. However, in alternative embodiments, the first part or lock plate may be mounted on support base28and the second part may be secured to the user support platform15.

FIGS. 12, 13 and 16Aillustrate the locking mechanism in the released or unlocked position, in which the lock pin is retracted into housing118and not engaged in opening112. In this condition, user support15is unstable and can pivot or rock from side to side about axis20in addition to rotating about vertical pivot axis19during a rotary torso exercise.FIGS. 14, 15 and 16Billustrate the locking mechanism in the locked position in which lock pin118is advanced out of housing116and into opening112, locking the user support to the base so that the user support is in a stable, horizontal orientation throughout the exercise. The user can choose whether to perform the exercise with the user support in the stable, locked condition or in an unlocked, unstable or rocking condition, depending on whether or not they wish to employ core muscles to maintain the user support in a horizontal position during the exercise. The user can readily flip lock release tab126back and forth between the unlocked and locked positions ofFIGS. 16A and 16B.

When the user wishes to lock the device, they simply reach under the user support and rotate the lock control tab or switch lever126along with the attached switch lever body125from the first position illustrated inFIGS. 3, 12 and 13into the second position illustrated inFIGS. 6, 14 and 15. As the switch lever body125and attached cam member127rotate from the position illustrated inFIG. 16Ato the 180 degree rotated position ofFIG. 16B, the rear edge130of the pin housing116which engages angled cam face131travels along the inclined face to the end position illustrated inFIG. 16B, and spring129extends to urge lock pin118and the attached cam member127and sleeve125into the extended position under the action of spring129, so that pin118extends out of the housing and into locking engagement with lock plate opening12. This locks the user support platform15to the rotatably mounted base28and prevents tilting of the platform about pivot axis20. Rotation of the switch lever or tab126in the opposite direction rotates the cam plate back to the position ofFIG. 16A, so that the fixed rear edge130of the pin housing forces cam member127and thus pin118back into the retracted position ofFIG. 16A, again allowing the platform to rock back and forth about axis20. This lock mechanism is very easy for the user to operate with their thumb or a finger, simply flipping lever or tab126back and forth between the locked and released positions, and the mechanism can be operated by a user when supported on the user support or prior to engaging the user support. Although a spring and cam mechanism is used for extending and retracting the lock pin in the embodiment ofFIGS. 3 to 16, other pin or plunger extension and refraction mechanisms may be operated by rotating tab or lever126in alternative embodiments.

The exercise machine10incorporating the releasably lockable, two directional pivoting user support12(or12A) inFIGS. 1A to 1C and 2is a rotary torso machine in which the user rotates their lower torso between left and right swiveled positions relative to the upper torso, back into an aligned, front facing position relative to the upper torso. However, it will be understood that the user support device12or lockable user support device12A may be used on other exercise machines for performing different exercises in other embodiments.

Rotary torso exercise machine10ofFIGS. 1A to 1Cbasically comprises a main frame having a base strut42and a main upright44, an upper torso stabilizing assembly45mounted at the upper end of main upright44, and the unstable kneeling user support device12(or12A) is mounted on rotational pivot assembly30supported on the base strut42of the main frame and configured for rotation of the user support device about vertical pivot axis19(seeFIG. 1B). In this embodiment, exercise resistance is provided by a selectorized weight stack48located in weight stack housing50secured to the vertical upright44via cross bar52and to base strut42via cross member or guide tube53. A selected amount of weight is secured to the rotating base28of the user support via one or more cables54extending around various guide pulleys in a conventional manner, as illustrated inFIG. 1A. Other types of exercise resistance may be provided in alternative embodiments.

User support base28is rotatably mounted on base plate55which is secured to base strut42via a pivot pin56at the center of plate55which is rotatably engaged in hollow mounting tube60which extends upwards from base plate28. Rotational range adjustment lever29is pivotally secured to the mounting tube60and extends outwardly and upwardly at an angle from tube60so that it is conveniently located for gripping by a user kneeling on the platform in order to adjust the starting position for a rotary torso exercise. A user can adjust the user support device to a desired exercise starting position at an angle to the right or left of a forward facing position in alignment with the upper torso by gripping and pulling the handle and rotating the user support device to the desired position.

The upper torso stabilizing assembly45is secured to main upright44via four bar pivot assembly61and comprises a pair of stabilizing handles62and a pair of upper torso stabilizing pads64for engaging the user's chest. Handles62and pads64are mounted on a support post71secured to the forward end of the upper pair of bars of the four bar pivot assembly61via mounting bar63. A range of motion (ROM) device65between the upper and lower bars of the four bar pivot assembly allows user adjustment of the height of chest pads64and handles62so that the pads are at chest level. Device65comprises ROM plate67also secured to support post71and having a series of openings69. Range of adjustment knob66is mounted on a forward end of one of the lower bars of the pivot assembly, as illustrated inFIG. 8, and extends into an aligned opening in ROM plate67. Range adjustment knob66is released from the ROM plate67by a user to allow the height of the pads to be adjusted, and is then released to engage in the appropriate opening when the pads are at the desired chest level height. Gas springs73extend between the upper and lower bar of the four bar pivot assembly on each side of the assembly.

FIG. 1Aillustrates a first start position for a rotary torso exercise in which the user support device12is rotated to the left of a central position aligned with the upper torso stabilizing assembly45.FIG. 1Billustrates a user70kneeling on user support pad15with the user support in the position ofFIG. 1A, with their upper torso rotated to the right to engage the chest support pads64while they grip handles62. The central position is illustrated inFIG. 1C. In the central position, the user support device10faces the main upright and the lower torso of a user kneeling on the support pad15is aligned with the upper torso. In an alternative or second start position for a rotary torso exercise, the user support device10is rotated to the right of the central position, i.e. facing in the opposite direction toFIGS. 1A and 1B, and the user rotates their upper body to the left to engage the upper torso support. The start position may be adjusted by the user by gripping the handle of adjustment lever29, pulling it towards their body so as to lift a pin72out of one of two slots74on opposite sides of the lower fixed plate or base plate55of pivot assembly30, then rotating the user support device into the desired adjusted position and releasing the lever29so that the pin72drops back into aligned slot74. The angular length of slots74controls the amount of rotation of the lower torso relative to the upper torso.

In order to perform the exercise, the user70first adjusts the kneeling user support device10to the desired starting position, i.e. degrees of exercise range to rotate lower torso to face forward alignment with upper torso. Exercise is performed in one direction, starting either from the position ofFIGS. 1A and 1B, or the oppositely directed position. Once the user support device12or12A is in the desired start position, user70assumes a kneeling upright position on the kneeling platform, as illustrated inFIG. 1Bfor the starting position ofFIG. 1A. Note that the kneeling platform rocks side to side about axis20during this positioning, unless locked against this rocking movement by locking mechanism14where user support assembly12A replaces assembly12ofFIGS. 1A to 2. The side to side rocking requires balancing using core muscles to keep the user support platform level and thus adds difficulty to the exercise.

The upper torso stabilizing pads/handles assembly45is then adjusted so the pads64are at chest level, using ROM device65. Once the pads are locked in position, the user grasps the handles and pulls their chest tight to pads for stabilization, as illustrated inFIG. 1B. Alternatively, the exercise may be performed using handles62only to stabilize the upper torso, keeping the chest off the pads64during the exercise. This provides an added level of core engagement.

Once the user is properly positioned on the kneeling platform or user support device12or12A, while gripping handles62and optionally engaging the chest pads of the upper torso support assembly45, the user's lower torso is in a rotated away position from the upper torso. In the start position ofFIG. 1B, the lower torso is rotated to the left relative to the upper torso. In order to perform the exercise, the user rotates their lower torso and the user support platform15on which they are kneeling to the right, into alignment with the stabilized face forward position of the upper torso, using a slow controlled movement, and ending up in the end position ofFIG. 1C. During this movement, the user exercises core muscles in order to keep the kneeling platform15of unstable user support device10balanced during the movement. Alternatively, when the user support assembly12A ofFIG. 3with the releasable locking mechanism14replaces user support12, the user can choose to perform an easier exercise with the user support platform locked in the horizontal or substantially horizontal orientation, by moving the locking pin into the locked position, as described above. When the user's body is in the central position ofFIG. 1C, the lower torso and user support device are rotated back to the starting position ofFIG. 1Band the exercise is repeated for the desired number of repetitions. The platform is then readjusted to the opposite starting position, the user70kneels back on the kneeling pad15, and again grips the handles42and pulls the chest pads64in to their chest. In this start position, the lower torso is rotated to the right of the upper torso. They then rotate their lower body on the user support device20or20A to the left, back into the forward facing or central end position ofFIG. 1C, and the exercise is repeated for the desired number of repetitions. Load bearing cable54linked to the selected number of weights in weight stack48provides the desired amount of resistance to rotation of the user support device between either start position and the end position.

The user support device or assembly12or12A is designed to provide a level of instability for the purpose of greater challenging the core muscles to balance the platform while performing the exercise motion. The kneeling platform instability may be provided in any or all planes to aid in engaging the core muscles. The unstable plane selection for the user support device ofFIGS. 1 to 10is left to right or side to side. The degree of instability is approximately 5 degrees off horizontal, left or right. The rubber bumper pads26contact the undersurface of the platform when tilted through five degrees to the left or right, limiting the amount of instability. Different degrees of instability may be provided in alternative embodiments by bumper pads of different heights, for example the platform may be tiltable through an angle in the range of about 3 to 10 degrees off horizontal. The more weight stack resistance selected, the greater degree of aided core muscle engagement necessary to keep the kneeling platform balanced. For an added level of core engagement, the handles alone may be used to stabilize the upper torso while keeping the chest off the pads during the exercise motion. By incorporating modified user support assembly12A into machine10in place of user support assembly12, the user is able to select whether or not to use core muscles to keep the platform15balanced during the exercise, simply by rotating switch lever or lock release tab between the unlocked and locked positions ofFIGS. 4 and 5.

The releasably lockable, unstable user support device12A in the previous embodiment is designed to support a user in an upright kneeling position. In alternative embodiments, the unstable user support device may be designed to support users in different positions, such as seated positions.FIGS. 17 to 22illustrated an abdominal exercise machine200incorporating a second embodiment of an unstable user support device202which is designed for supporting a seated user, and includes a manually releasable locking mechanism204for releasably locking the user support against rotation about one pivot axis. Device202may be used to replace a stable user support seat on an abdominal exercise machine designed for supporting a seated user.

Some other examples of exercise machines on which unstable seated user support device80may be used are upper body exercise machines such as biceps curl exercise machines, seated mid row exercise machines, pec fly exercise machines, and chest press and shoulder press exercise machines. Some examples of such exercise machines on which unstable user support device80may be used are the RS-1102 biceps curl exercise machine, the RS-1203 seated mid row exercise machine, the RS-1302 pec fly exercise machine, the RPL-5301 chest press exercise machine, and the RS-1501 and RPL-5501 shoulder press exercise machines which all have rocking seats and are manufactured by Hoist Fitness Systems, Inc. of San Diego, Calif., or any of the rocking user support exercise machines described in U.S. Pat. Nos. 7,717,832, 7,760,269, 7,766,802, 7,794,371, 7,901,337, 7,938,760, 7,976,440, 7,981,010, 7,993,251, and 8,002,679 of Hoist Fitness Systems, Inc. The unstable user support device202with releasable locking mechanism204may also be used on other types of exercise machines with rocking user supports in alternative embodiments.

The abdominal exercise machine200ofFIGS. 17 to 22is similar to the abdominal exercise machine described in U.S. Pat. No. 8,172,732 of Webber et al. ('732 patent), and has a swiveling seat as described in U.S. Pat. No. 7,867,149 of Webber et al. ('149 patent), and the contents of each of the aforementioned patents are incorporated herein by reference. In the machine200of this embodiment, the releasable locking mechanism of the '732 and '149 patents is replaced with locking mechanism204which is similar to locking mechanism14described above in connection withFIGS. 3 to 16, as described in more detail below. In one embodiment, machine200has a main frame214on which the user support assembly202is pivotally supported at a location spaced above the ground. The user support assembly includes a user support pad or platform215which is pivoted for movement about two different pivot axes, as explained in more detail below. A pivoted exercise arm assembly216is linked to the user support assembly202by a connecting link217to control movement about one of the pivot axes, and is also linked to a selected number of weights in weight stack218to provide exercise resistance.

The exercise arm assembly216is pivoted to an upper part of the main frame214for rotation about a first horizontal pivot axis222, while the user support assembly202is pivoted to the frame at a location spaced below the first pivot axis for pivotal motion about a second horizontal pivot axis225parallel to the first pivot axis. A user seated on the user support pad215pulls down on handles226to perform an abdominal exercise, so that the exercise arm assembly pivots downward about axis222while the user support assembly pivots upward about axis225.

The user support assembly202is illustrated in more detail inFIGS. 19 to 22with the user support pad or platform215removed to reveal details of the releasable lock mechanism204. Assembly202includes base having a base strut224which is pivoted to the main frame for rotation about pivot axis225via cross bar227. User support platform215is rigidly mounted on user support frame223, which in turn is pivotally mounted on the base or strut224for swiveling about a pivot axis275extending transverse to user support platform215via pivot pin extending into pivot sleeve276on the upper surface of base strut224, as best illustrated inFIG. 22. A mounting plate beneath user support pad215is secured to the base frame via fasteners228. A stabalizing support256for engagement by the user's lower legs is provided at the end of strut230which extends downward from a forward end of member232of frame223on which the pad215is supported. Stabilizing support256comprises a pair of roller pads designed to engage over the feet of a user when seated on the support assembly. In alternative embodiments, the stabilizing support may alternatively comprise one or more foot plates on which the user's feet rest, or one or more knee or leg pads designed to engage in front of the user's knees or shins.

In the embodiment ofFIGS. 17 to 22, manually releasable locking mechanism204replaces the locking device described in U.S. Pat. No. 7,867,149 and is easier to use. Mechanism204is similar to locking mechanism14of the previous embodiment, and like reference numbers are used for like parts as appropriate. In this embodiment, the first part or locking plate234is mounted at the forward end of pivoting base strut224rather than depending from user support215which is engaged by the user, and second part235which includes retractable lock pin118is mounted on the downwardly depending strut230of the user support frame223. As in the previous embodiment, rotation of the manually engagable tab or switch lever126between the unlocked position illustrated inFIG. 20and the locked position illustrated inFIG. 19moves lock pin118between a retracted position in which it does not engage the opening in locking plate234and an extended position in which pin118engages the aligned opening (seeFIGS. 18 and 22) to lock the user support or seat against rotation about vertical axis275. The lock actuating mechanism in this embodiment is identical to the mechanism illustrated inFIGS. 16A and 16Band described above, and is therefore not described in detail. Because entering and exiting a free swiveling seat can be awkward, the locking mechanism may be used to temporarily secure the seat in a centered, forward facing orientation, and then refracted to allow free swiveling of the seat during an exercise. Alternatively, if the user wishes to perform the abdominal exercise in a stable position without engaging core muscles, the seat may remain locked in position throughout an exercise.

To perform an exercise, a user sits on the seat pad with their buttock up against tail bone pad or secondary support258which is supported on the rear end of base strut232, knees bent over the front edge of the seat pad and their feet hooked behind the stabilizing roller pads256. The user then unlocks the user support frame223from the base strut224by reaching down in front of the seat and rotating locking tab or switch lever126from the position illustrated inFIG. 19to the position illustrated inFIG. 20, if they wish to perform the exercise on a free swiveling seat. Next, the user leans back against user engaging back and head pads240,242on the exercise arm216, grabs the user engaging handles226and pulls the handles forward in a downward motion. This action pulls the user engaging pads into contact with the user's head, upper back and shoulders, pushing them forward and downward and causing the user's upper body to bend just below the rib cage and activate the upper abdominal muscles. At the same time, the connecting link217attached to the exercise arm is pushed down by pivotal movement of exercise arm216in an anti-clockwise direction about pivot axis222, simultaneously pushing the lower pivoting cross strut227of the user support assembly to pivot downwardly in a clockwise direction about pivot axis225. This simultaneously pivots the rear end of base support or strut224downwards and lifts the forward end of strut224upward in a rearward direction, simultaneously tilting the user support upward and rearward. This movement lifts the user's knees while it lowers the user's hips, causing the user to bend forward at the waist, activating the lower abdominal muscles. The combined movement of upper and lower body produces a compound movement abdominal exercise.

Swiveling, side-to-side movement of the user support about pivot axis275is supplied by the pivotal connection to the base support or base strut224via a pivot axle which engages in pivot sleeve276as seen inFIG. 22. This is an unrestricted, free-swiveling movement that is controlled by the user. It allows the user to pivot the seat from side to side as the user support movement arm52is pivoted by actuation of the exercise arm assembly, involving a greater number of torso muscles. Swiveling the knees to one side or the other involves the oblique muscles as well as the upper and lower abdominal muscles. Just trying to prevent the seat from swiveling and keeping it centered during the exercise movement requires core stabilizing muscles in the abdominal and low back area to become involved. The end result is a movement pattern that provides simultaneous vertical and horizontal seat movement that involves multiple muscle groups and requires multiple joint actions. If the user wishes to perform a simple abdominal exercise without engaging the core stabalizing muscles, they can easily reach down in a centered position and rotate locking tab or switch control lever126back from the released or unlocked position ofFIG. 20to the locked position ofFIG. 19.

The unstable user support devices described above allow for tilting or rocking of a user support platform from side to side through a limited angle of rotation about a pivot axis parallel to the support platform, or rotation of a user support seat from side to side about a pivot axis extending transverse to the seat, so as to involve core muscles to stabilize the support platform while performing various types of exercises, including exercises performed in kneeling and seated positions. Although the rocking or rotation in the described embodiments is about a single pivot axis different from the main user support pivot axis or rocking axis, tilting about different axes may be provided in alternative embodiments, including an alternative embodiment with a universal or multi-directional pivot connection between the mounting bracket or base and the user support platform. The instability of the user support platform may therefore be provided in multiple directions or planes, and through any desired angular range. The instability of the user support platform challenges the core muscles in balancing the platform while performing the exercise, providing enhanced exercise and training. At the same time, the manually releasable locking mechanism provided in the above embodiments allows a user to switch easily back and forth between an unstable or freely swiveling user support, and a locked user support which rotates only about a single or main rocking axis.