Abstract: The instant invention provides a portable, compact and easy held exercise apparatus that uses two or more resilient members, a securing structure surrounding the resilient members and at least two straps, each attached to one resilient member, to provide flexing resistance exercises to a number of muscle groups of the body.

Abstract: A neck exercise apparatus comprises a thin elongate leaf spring spanning between two supports. One or both of the supports includes a clamping actuator configured for clamping the leaf spring to the support during exercise. The actuator is also configured for releasing the clamping force, thereby permitting adjustment of the position of the support along the length of the leaf spring. Lower ends of the supports are configured to permit the supports to pivot over a flat support surface as the leaf spring is flexed during exercise.

Abstract: An adjustable scissors-action exerciser includes two motion arms pivotable relatively to each other and adjustably set in one of multiple operation angles. When the operation angle between the two motion arms grows beyond a predetermined angle, a locking mechanism is unlocked to allow the user to adjust the operation angle of the scissors-action exerciser. When the operation angle between the two motion arms is reduced within a predetermined angle, the locking mechanism is locked.

Abstract: The present invention features a a muscle strengthening exerciser to be worn at specific parts of the body. This inventive muscle strengthening body frame apparatus can be worn on isolated body parts as non-apparel items for direct longitudinal resistive forces exerted on the body part of the wearer during movement. The apparatus comprises a frame assembly consisting of a first and second portions which are joined together by a resistance bar. The resistance bar provides the resistive forces providing muscular activity to adjacent body parts.

Abstract: An exercise machine includes a bench and board section including a stationary bench having first and second opposite ends, and a board having first and second opposite ends, with the first end of the board pivotally mounted adjacent the second end of the stationary bench, each of the bench and board being formed substantially from a single piece which can selectively support a torso of a person and legs of the person, and a resistance device in contact with the single piece board and which applies a resistance to pivotal movement of the board, while permitting the board to swing up and down against a resistance applied by the resistance device.

Abstract: An exercise device has a pair of handle portions that are connected by a pair of connection portions to form an annular body. The pair of connection portions have a flattened cross-section that provides a rotation bias towards a rest configuration. The rotational bias of the pair of connection portions enables a twisting exercise that is useful for strengthening the hands and forearms of a user.

Abstract: An improved device for athletic exercise by pulling at a resisting force. The device consists of a number of spring housing assemblies that are stacked and clamped in a column with at least one pulley wheel assembly to which a cord and pull handle is attached. A grooved metal shaft is disposed throughout the column longitudinal axis to drive all the constant-force spring assemblies which are stacked inside the device when the pulley wheel is caused to rotate. A person uses the device by first selecting which spring assemblies he wants to produce a particular resisting force level, by pushing separate selector levers, one for each spring. He then pulls at the pull handle to experience the chosen resisting force. The device design allows a user the choice of many resisting force levels, using only a small number of spring assemblies. The device is small, light in weight and conveniently shaped for easy attachment to any suitable restraining object.

Abstract: A demountable multi-purpose exercise device including a pair of elongate plunger members, a central guide member having a pair of oppositely disposed portions for demountable telescopic engagement with the pair of elongate plunger members. Further included is a depressible resilient means disposed between the pair of elongate plunger members and the central guide member, operative to permit mutual contraction of the plunger members in response to opposing axial forces applied thereto. There is an elongate flexible member longitudinally looped about the exercise device in engagement with the pair of elongate plunger members. Further, there are included, for use with the exercise device an exercise apparatus comprising retractable spool or drum members in cylindrical casings and elongate flexible members fixably attached and resiliently coiled about the spool members to be uncoiled in response to a force applied thereto.

Abstract: The portable flexible exercise device is a quadrilateral with handles at the corners. Compression members extend between the adjacent handles and are pivoted thereto. A tension member is engaged so that one pair of opposite handles is resiliently urged apart while the other pair is resiliently urged together so that the exercise device can be utilized in different forms of exercise.

Abstract: An exerciser includes a shaft rotatably disposed on a base, a housing rotatably engaged on the shaft and having a chamber formed by an outer peripheral wall which has a groove, a belt wound around the tube for rotating the housing, a barrel received in the chamber of the housing and secured to the shaft and having a slot. A coil spring is received in the housing and has two ends engaged into the slot of the barrel and the groove of the outer peripheral wall of the housing. A cover includes a space formed by an outer peripheral fence, to suitably enclose the chamber of the housing.

Abstract: Hip Rotation Training Device with a base plate, a torsion resisting element such as a torsion spring, a torsion spring attachment rod, an inner vertical support tube, a tube support socket, an outer vertical support tube and a hip retaining assembly. The tube support socket is fixedly attached to the base plate. The torsion spring is fixedly attached to the bottom of the inner vertical support tube. The spring attachment rod is fixedly attached to bottom of said torsion spring, said spring attachment rod slidalbly attached at its opposite end to said tube support socket and held in place by a cross pin.

Abstract: An exercise device comprises left and right hand levers each including a rod and a pivot seat attached to one end of the rod; a pull member consisting of a stem and a block, the stem being vertically disposed in the center of the block; a torsion-adjusting mechanism sleeved onto the stem; and two arms, one of which has two ends pivotally connected to one end of the block and the pivot seat of the left hand lever, respectively, and the other of which has two ends pivotally connected to the other end of the block and the pivot seat of the right hand lever, whereby a user grips one end of the left and right hand levers with his two hands and apply a bending force thereon to achieve the object of exercise of the arm portion.

Abstract: An exercise device guides the user during performance of a squatting exercise while the exercise device repetitively moves down and up any suitable vertically oriented surface, such as a wall. During performance of the squatting exercise the user rests against a back support surface. Rolling members provide for a smooth rolling contact between the exercise device and the wall during performance of the squatting exercise. A grip member, or members, positioned distal from the rolling members and in front of the user provides the user with ready and true control over the exercise device during the performance of the squatting exercise. The squatting exercise achieved using the exercise device strengthen or otherwise tone many muscle groups including the quadriceps, the knees, the hamstrings, the ankles, the glutenous maximus, the abdomen and the lower back.

Abstract: A multi-directional swivel body builder constitutes a bent shank, two sections of joint tube having a ring groove and a lock hole at its far end. The joint tube houses a retaining spring having a turnover leaf and a lock post fitted into the lock hole of the joint tube. The joint tube is inserted into the sleeve tube of the handle. The sleeve tube provides a plurality of adjusting holes. When the joint tube slides in place in the sleeve tube, the catch lug on the inner wall of the sleeve tube will enter the ring groove of the joint tube and press the retaining spring so to allow the handle to move freely along the ring groove for proper angular adjustment. The far end of the handle links with an end wheel. When waving the end wheels with two hands, the bent shank will rotate in cycle.

Abstract: A multipurpose hand puller mainly comprises at least one set of hand pullers, pedals, handgrips and operation levers, in which each set of the puller consists of a casing, brake mechanism, sheave and pulling rope. The delicately designed structure and diverse manipulation of a handgrip and operation lever provide a great number of combination and multipurpose exercises with least space occupied and maximum benefit achieved.

Abstract: A folding portable exercise apparatus having a contoured chest bar and a contoured lap bar. Two pairs of rods connect the bars. Each pair of rods is joined by a coil spring. An adjustable belt may be fastened around underneath the user. The device may be used to exercise the upper abdominal muscles, the triceps, the biceps, the pectoral muscles, the latissimus muscles, the back and lower abdominal muscles and the leg muscles such as calves, quadriceps, hamstring and gluteal muscles. The device may be disassembled and folded into a compact arrangement for storage and travel by detaching the coil springs from one pair of rods. This allows the device to be separated into components. The four rods may lie in the cavity along the major length of the respective chest bar and lap bars. The belt, springs and thumbscrews may then also lie together within the cavities and when closed produce a compact package the length and width of the chest bar and lap bar.

Abstract: A portable personal training and exercise device having a base assembly, a pole assembly and cable and pulley assembly. The base assembly has a tilt mechanism for holding the pole assembly in different orientations. The cable and pulley assembly is attached to the pole assembly and has two coaxial pulleys rotatably mounted on a common single stationary shaft. Each pulley is spring biased for rewinding a cord onto the pulley. The cable and pulley assembly also has a tension adjustment unit for adjusting the resistance of the pulleys, and two multi-direction guide units mounted on the housing of the cable and pulley assembly for allowing the pulley cords to be pulled in multiple directions with reduced friction. A user may pull the cords of the pulleys for exercising various muscles of the user and adjust the resistance force of the cords at an appropriate level suitable to the user.

Abstract: A height-adjustably mounted apparatus has a flexible supply line that is conducted to the apparatus from above and is provided with a weight compensation device so that the apparatus can be easily adjusted to different vertical positions. The weight compensation device includes a cable drum that accepts a first carrying cable which is loaded with the height-adjustably mounted apparatus and is subjected to a force directed opposite to the weight of the device and the weight compensation device includes a second carrying cable that is accepted on the cable drum and has an end secured to a supply line at a fastening location, so that the fastening location is lifted by the second carrying cable during vertical adjustment of the apparatus.

Abstract: This invention describes a novel gravity-independent exercise unit designed for use in microgravity, or on the ground, as a means by which to counter muscle atrophy and bone degradation due to disuse or underuse. Modular resistive packs comprising constant torque springs provide constant force opposing the withdrawal of an exercise cable from the device. In addition to uses within the space program, the compact resistive packs of the CFREU allow the unit to be small enough for easy use as a home gym for personal use, or as a supplement for rehabilitation programs. Resistive packs may be changed conveniently out of the CFREU according to the desired exercise regimen. Thus, the resistive packs replace the need for expensive, heavy, and bulky traditional weight plates. The CFREU may be employed by hospitals, rehabilitation and physical therapy clinics, and other related professional businesses.

Abstract: A chest exerciser includes a hollow seat with top and bottom walls, and left and right side walls interconnecting the top and bottom walls. Each of the side walls has a horizontally extending slide groove which has front and rear groove ends proximate to front and rear ends of the hollow seat, respectively. Each of a pair of lever members includes an inner shaft which has a pivot end extending through the slide groove in a respective side wall and pivoted to the hollow seat about a vertical pivot axis, an outer tube sleeved on the inner shaft and having an abutment end abutting against an outer wall surface of the respective side wall, and a resistance unit for providing resistance to relative axial movement between the inner shaft and the outer tube.

Abstract: An exercise device has a pair of handle portions that are connected by a pair of connection portions to form an annular body. The pair of connection portions have a flattened cross-section that provides a rotation bias towards a rest configuration. The rotational bias of the pair of connection portions enables a twisting exercise that is useful for strengthening the hands and forearms of a user.

Abstract: A resistance adjustment mechanism for an easy pull exerciser mainly comprises an outer shell, adjustment device, winding wheel and gear axis. The outer shell is composed of the first and second shells. The first shell has an adjustment device containing a rotating knob, a retainer and a one-way clutch bearing. The retainer is clamped and attached to the first shell with outside for the rotating knob's thread stud to pass through. Normally, the teeth on gear axis match the inner ring gear of the second shell. A flexible arrangement for gear axis makes the gear axis rotate under inward pressure, so the degree of tightness for the spiral spring can be adjusted to control the resilient force for the pull string. Therefore, when back to the normal state, the gear axis is positioned to the inner ring gear. The mechanism provides easy adjustment and secured position for the gear axis.

Abstract: A rhythmic motion driver having a case containing flywheels and a guide along which the flywheels move linearly while rotating. A spring is within the case that compresses and expands in response to oscillatory motion of a bar that extends through an opening in the case. The spring compression and expansion is slowed but not dampened by the movement of the flywheels.

Abstract: An exerciser includes an exercise module defined by hinged first and second plates with a spring therebetween to provide biasing resistance, and a bracket member for attaching the exercise module to a surface such as a bed. The exerciser provides a simple means for exercising, especially for users in a supine position.

Abstract: A collapsible combination waist and leg exerciser comprises a base, two elastic frames, and two connected handles. In use, user may stand on base with hands grasped on the handles and bend waist forward facing elastic frames in order to exercise up and down repeatedly. User may also sit on a chair with the chair's legs pressed on base by the weight of user. User's feet are urged against the top of handles for exercising up and down repeatedly. User may lay back with feet urged against the top of handles in a continuous up and down movement. This can train or develop the parts of body such as chest, arms, waist, legs, and buttock effectively in a small environment.

Abstract: A resistance exerciser aimed at working the core muscles of a human body.

Abstract: The invention relates to different embodiments of an exercises apparatus in which the pulling motion exerted on a cable system is transmitted to a brake device so as to generate a load on the user. The invention relates in particular to examples of how the apparatus can be used to simulate different kinds of movements. To this end the apparatus has a modular structure and/or advantageous mechanical additional elements of the apparatus permit a multiple use thereof.

Abstract: An exercise wheel comprises a housing, two grip rods respectively secured to two sides of the housing, a chassis housed by the housing, a main shaft supported by the chassis, a main gear mounted around the main shaft, two wheel assemblies, and two torsion springs. Each wheel assembly is rotatably mounted to the chassis and includes a shaft with a toothed portion for meshing with the main gear. The torsion springs are mounted around the main shaft and respectively located on both sides of the main gear. Each torsion spring includes a first end securely attached to the housing and a second end securely attached to the main gear. The main gear comprises a peripheral stop surrounding at least one of the torsion springs to thereby avoid radial outward expansion of the torsion springs resulting from movements of the wheel assemblies in a rearward direction.

Abstract: An exercise device for a person. The exercise device includes mounting straps for mounting on each of two body members on opposite sides of a selected joint of the person, a support member connected to each mounting strap, and a resistance mechanism interconnecting the support members for exercising at least one of the two body members upon repeated moving at least one of the members. The selected joint comprises one of a knee, a hip, an ankle, a wrist, an elbow, and a shoulder. The resistance mechanism includes one of a damper and a pulley with associated rubber bands connected to the oppositely disposed support members.

Abstract: An exercise apparatus including a platform, attached to a resilient member, which can rotate, twist, and tilt in every angle while also providing a resistance force to all degrees of movement. The resilient member is also attached to a base, such that strength, agility and balance can be trained while also providing a cardiovascular workout. The platform may be modified by the addition of an elastomeric material over its surface to provide additional traction or padding. The platform may also have notches placed around its perimeter, through which resistance tubing or rope may be placed, such that upper body resistance motion may be integrated into the exercise apparatus. Furthermore, support members may be disposed under both the platform and base for additional support and rigidity. The base may also be in the form of legs extending out from a central portion.

Abstract: An exercise device for enhancing the mobility of a user who may be suffering from tendinitis of the wrist. The device includes a forearm brace portion that is hingeably connected to a hand brace portion with a spring element connecting the two brace portions together. The spring element can be changed to vary the resistance against which the user works. Straps and loops connect portions of the user's hand and forearm to the device.

Abstract: A torsion board comprising a platform for supporting a user, a ground contacting member for maintaining the torsion board generally in a fixed position and orientation with respect to a ground surface and a resilient interconnecting member mounted between the ground contacting member and the platform to permit pivoting of the platform about first, second and third orthogonal axes, said first axis being generally coincident with a gravitational axis along which gravitational forces act upon said user.

Abstract: An exercise wheel comprises a housing, two grip rods secured to two sides of the housing, respectively, a chassis housed by the housing, a main shaft supported by the chassis, a main gear mounted around the main shaft, and two wheel assemblies rotatably mounted to the chassis and each including a shaft with a toothed portion for meshing with the main gear. Two torsion springs are mounted around the main shaft and respectively located on both sides of the main gear. Each torsion spring includes a first end securely attached to the chassis and a second end securely attached to the main gear. The main gear further comprises a peripheral stop surrounding at least one of the torsion springs to thereby avoid radial outward expansion of the torsion springs.

Abstract: This invention describes a novel gravity-independent exercise unit designed for use in microgravity, or on the ground, as a means by which to counter muscle atrophy and bone degradation due to disuse or underuse. Modular resistive packs comprising constant torque springs provide constant force opposing the withdrawal of an exercise cable from the device. In addition to uses within the space program, the compact resistive packs of the CFREU allow the unit to be small enough for easy use as a home gym for personal use, or as a supplement for rehabilitation programs. Resistive packs may be changed conveniently out of the CFREU according to the desired exercise regimen. Thus, the resistive packs replace the need for expensive, heavy, and bulky traditional weight plates. The CFREU may be employed by hospitals, rehabilitation and physical therapy clinics, and other related professional businesses.

Abstract: An exercise wheel comprises a housing, two grip rods secured to two sides of the housing, respectively, a chassis housed by the housing, and two wheel assemblies. Each wheel assembly comprises a shaft mounted between two side walls of the chassis, two wheels mounted in the housing and connected by the shaft to thereby allow rotational movement of the wheels, and a torsion spring. The torsion spring has a coil portion mounted around the shaft, a first end securely attached to one of the wheels, and a second end securely attached to one of the housing and the chassis. Rotational movement of the wheels in a forward direction is stopped when the torsion spring is twisted such that the coil portion of the torsion spring is in contact with an outer periphery of the shaft. A sleeve is mounted around the coil portion of the torsion spring to prevent radial outward expansion of the coil portion when the wheels are moved in a direction opposite to the forward direction.

Abstract: A sliding exerciser includes a body unit equipped with a front castor and a transversely extended top handle, and a damping unit, the damping unit including a revolving shaft disposed in parallel to the wheel axle, an elastic cord member coupled to the revolving shaft, two wheels, a wheel axle coupled between the wheel and adapted to alternatively roll up and release the elastic cord member when the user pushes and pull the sliding exerciser on a flat surface.

Abstract: Methods of use of a portable in-bed exercising machine are provided for strengthening and/or strength maintenance of the musculature and ligaments associated with an extremity. The exercise apparatus employs the principles of closed kinetic chain exercise of the extremity in both concentric and eccentric modes and for isometric, isotonic and isokinetic exercise. Each extremity is engaged separately allowing for bilateral, unilateral and reciprocal motion. As exemplified for lower extremities, force is actively applied to the feet with each lower extremity having the force level continuously adjustable from zero force to a force equal to or greater than body-weight The exercise motions and force applications use the same major muscle groups as functional activities such as standing from a chair, climbing stairs walling, jumping and jogging. Vertical support is provided for the lower extremity to stabilize and control the lower extremity motion within safe limits.

Abstract: An exercise wheel includes a housing, a chassis housed by the housing and including a compartment, a pair of rollers rotatably mounted in the compartment of the chassis and connected by a shaft, a main gear rotatably mounted in the compartment of the chassis, and a transmission gear for providing transmission between the shaft of the rollers and the main gear. Two torsion springs are respectively mounted to two sides of the main gear and each has a first end and a second end. The first end of each torsion spring is attached to an associated side of the main gear. The second end of each torsion spring is attached to the chassis. Each of the torsion springs is deformed to store resilience when the main gear is turned, thereby returning the main gear. Two grip rods are secured to the two sides of the housing, respectively. A universal caster is mounted to an underside of the chassis, thereby allowing the user to change moving direction of the exercise wheel.

Abstract: A leg swing exerciser for a walker includes a support bar with a threaded hole defined in each end and a shoulder formed on each end. An attachment bar attached to the support bar and two springs respectively mounted around each end of the support bar. The spring abuts the shoulder of the support bar. Two swing arms each with a pivot ring pivotally mounted on opposite ends of the support bar and abutting the spring, and a pedal attached to the other end. A bolt with a head extending radially outward from one end is screwed into the threaded hole of the support bar to hold the swing arm and the spring in place.

Abstract: A muscle strengthening apparatus comprising a substantially arch-shaped member having a first end and a second end, the arched-shaped member having a predetermined degree of resiliency, an ankle contact member having a pair of ankle contact portions for contacting the ankles of a user, the ankle contact member being attached to the arch-shaped member adjacent to the first end, and a buttocks contact member for contacting the buttocks of the user, the buttocks contact member being attached to the arch-shaped member adjacent the second end.

Abstract: A cord controlling device is used in conjunction with a game racket and is composed essentially of a housing formed of a base and an upper cover. The base is provided with a fastening portion by which the device is fastened with the head frame network of the game racket. The base is provided at the center of the upper side thereof with a shaft on which a rotary seat is rotatably mounted. The rotary seat is provided with a receiving chamber in which a volute spring is located such that the volute spring is fastened at one end thereof with the rotary, seat, and at other end thereof with the shaft of the base. A cord reel is mounted on the rotary seat for winding up or letting out a cord which is wound on the cord reel such that the cord is fastened at one end thereof with the cord reel, and that other end of the cord is let out via a cord outlet of the housing for fastening with a ball.

Abstract: An exerciser has a rod engaged through a frame, and a wheel rotatably engaged on the rod and having one or more holes for threading a resilient belt which is received in the rod and which has two ends retained to the ends of the rod. The middle portion of the belt is engaged through either of the holes of the wheel and may be wound around the rod when the wheel is rotated relative to the rod. The frame has one or more wheels for facilitating moving of the frame and has one or more pulleys for winding the belt. Two pulleys are rotatably engaged on the rod for winding the belt.

Abstract: The present invention relates to the field of knee down push-pull assistive exercise with a compact mobile exercise machine that exercises the abdominal, back and arm muscles in the kneel-prone-kneel movement. The push-pull tractor has a roller in contact with a random supporting surface, a handle offset to the roller axis to support a portion of operator body weight and an energy storage device that returns the tractor towards the starting position. In several embodiments, a wheel is added to the tractor to counteract windup torque energy.

Abstract: A therapeutic exercise apparatus for use by a patient comprises a base and a tubular post pivotally mounted at a lower end thereof to the base for pivotal, back and forth movement about a pivot axis. Springs are used to urge the tubular post toward a substantially upright position. A handle is mounted distal from the lower end. The tubular post and the springs are adapted to provide only nominal (light) resistence to the tubular post pivoting about the pivot axis to allow the therapeutic exercise apparatus to be used by weak patients, such as accident victims, to regain use of a limb.

Abstract: A portable in-bed exercising machine is provided for strengthening and/or strength maintenance of the musculature and ligaments associated with an extremity. The exercise apparatus employs the principles of closed kinetic chain exercise of the extremity in both concentric and eccentric modes and for isometric, isotonic and isokinetic exercise. Each extremity is engaged separately allowing for bilateral, unilateral and reciprocal motion. As exemplified for lower extremities, force is actively applied to the feet with each lower extremity having the force level continuously adjustable from zero force to a force equal to or greater than body-weight. The exercise motions and force applications use the same major muscle groups as functional activities such as standing from a chair, climbing stairs, walking, jumping and jogging. Vertical support is provided for the lower extremity to stabilize and control the lower extremity motion within safe limits.

Abstract: Variable Resistance Exercise Device with a resistance mechanism comprised of a housing, spring reel, extension cable and resistance applying knob. A strap helps attach the resistance mechanism to a persons arm or leg. An eye bolt or bracket is attached to a wall. A retaining clip attaches to the wall bracket at the end of the cable of the resistance mechanism. An alternate embodiment where the resistance mechanism is removably attached to a wall at one end and a user retaining or holding means attached to said cable at the opposite end. A preferred embodiment includes wherein said housing has a padded portion on its underside where it interfaces the users arm or leg.

Abstract: An exercise apparatus with a plurality of infinitely adjustable resistance mechanisms, a flat horizontal platform having a plurality of sockets located about its perimeter capable of receiving the resistance mechanisms and a pair of smaller arm sized platforms, also containing sockets, rotatably pinned to the main platform. The resistance mechanism has a constant force spring that allows a nylon cable to retract quickly and has a belville spring washer that increases resistance on the retractable cable as a tension knob is turned clockwise. A ratchet plate allows resistance to be felt on the outward pull of the cable but no resistance to be felt on the inward retraction of the cable. A ring member attaches to the nylon cable is capable of acting as a hand grip or a foot retainer.

Abstract: A exercise belt for exercising the upper body of a user. The exercise belt includes a belt and a pair of cable retracting devices coupled to the belt. Each of the cable retracting devices comprises a housing and a cable that is retractably extended from the housing. A pair of handles are coupled to free ends of the cables.

Abstract: A folding portable exercise apparatus having a padded chest bar and a padded lap bar. Two pairs of length-adjustable telescoping rods connect the bars. Each pair of telescoping rods is joined by a coil spring. An abdominal belt may be fastened around and underneath the user. The device may be used to exercise the upper abdominal muscles, the triceps, the pectoral muscles, and the back and lower abdominal muscles. The device may be disassembled and folded into a compact arrangement for storage and travel by detaching the coil springs from one pair of telescoping rods. This allows the device to be separated into two components. The telescoping rods may be folded so that they lie along the major length of the respective chest bar and lap bar. The belt may then be used to secure the two folded components together producing a compact package approximately the length and width of the chest bar and lap bar.

Abstract: A muscle strengthening apparatus comprising a first elongate member, a second elongate member, a feet securing member and a support member. The first and second elongate members have a pair of end portions. The feet securing member secures the feet of a user and is attached to an end of the first elongate member. The other end of the first elongate member has an engagement portion. The second elongate member is slidably engaged with the first elongate member. The axes of the first and second elongate members are substantially coaxial and the movement of the first and second elongate members is substantially linear. The apparatus further comprises a system for exerting a force on the first and second elongate members so as to urge the first and second elongate members in opposite directions. The support member is configured to contact the buttocks of the user and is attached to the other end of the second elongate portion.