CA2292553A1 - Sitting type lower limb bending exercise equipment - Google Patents

Abstract

A sitting type lower limb bending exercise equipment comprising a saddle (12) supported on a body (10) and load generating means (15, 16, 20) for placing a load on both lower limbs, wherein the load generating means (15, 16, 20) comprise pedals (13a, 13b) on which to place both legs respectively with the user seated and hip joints and knee joints bent and a pedal drive mechanism (21) for moving the pedals (13a, 13b) forward from behind the trunk of the user in the diagonally downward direction so that the hip joints and knee joints can be changed almost simultaneously from a flexion position to an extension position and ankle joints from a dorsal flexion position to a plantar flexion position.

Description

r SEAT-TYPE LEG BENDING EXERCISE APPARATUS
TECHNICAL FIELD
The present invention relates to a leg training apparatus, and more specifically to a leg bending exercise apparatus which promotes joint exercises of the hip joint, knee j oint and ankle j oint substantially equivalent to uphill walking or stair climbing.
BACKGROUND ART
In general, known seat-type leg bending exercise apparatus hold the hip j oint angle at a substantially fixed position in flexion. Even when the hip joint angle is altered, the angle change remains within the range of flexion. In their exercise mode, the hip joint angle is generally held in flexion, and the hip joint bending exercises are carried out with a limited flexibility within a range of flexion, accompanied by knee joint bending exercises under such restrictions.
Exercises of ankle joints include an exercise of independent plantarflexion and dorsiflexion and a comprehensive exercise of these joints in a sitting posture with the hip joint angle set in flexion.
Alternatively, the exercise a~baratllS inri"~ao bicycle ergometer which installs pedals forwardly of S
the saddle. In using the exercise apparatus of this structure, even when the hip j oint angle opens in the extension direction of the hip joint, the hip joint angle does not vary beyond the range of flexion as held at the start of the exercises.
As above, the known seat-type leg bending exercise apparatus effect exercises as holding the hip joint angle at a substantially fixed position in flexion. Even if the hip joint angle is altered to some degree, the angle remains within the range of flexion.
Hence, they show some drawbacks to be mentioned below.
Namely, while the hip joint angle is in flexion, the pelvis rotates backwardly at up to 22°. This rotation causes the spinal column to align straightly, in which posture a great muscular strength is required to maintain the posture of back muscles. Therefore, this posture prevents the back muscles from promptly receivingtheforcetransmittedfromthelegs. Besides, during exercises, the change of the hip joint angle in this posture shows such a poor flexibility that the moment of unexpected force may be imposed on abdominal muscles and back muscles as well as leg joints, depending on the magnitude or position of the imposed load. To be specific, when a load is imposed on a hip joint, with abdominal muscles and back muscles being i substantially in contraction, the pelvis and spinal column are to take an unduly heavy load and be exposed to a higher risk of injuries. Thus, the known exercise apparatus which continuously impose a load as holding the hip joint angle in flexion are unsuitable not only for healthy persons but particularly for those with a weak muscular strength such as handicapped or aged persons.
Moreover, the amount of employed muscles is limited in the exercises which continuously impose a load with the hip joint angle being held in flexion.
Hence, some of the muscles employed in cooperation with the joint exercises leave the joints with an extremely poor flexibility. Under this condition, the muscles related to the joint movement are not employed enough.
In addition, the known exercise apparatus used as holding the hip joint angle in flexion can be useful for independent bending exercises of the other leg joints. Nevertheless, such exercises fail to estab-lish cooperation between the joints, and there remain possibilities of imposing unexpected stresses on the other leg joints to cause injuries.
The present invention has been worked out in view of the above problems and intends to provide a seat-type leg bending exercise apparatus of a simple structure ~, which enables even frail persons such as handicapped or aged persons to perform antigravity exercises without imposing a burden on joints and the like nor raising the heart rate extremely, which provides a remarkable amount of exercise, and which effectively promotes the recovery of deteriorated athletic abilities.
DISCLOSURE OF THE INVENTION
The seat-type leg bending exercise apparatus of the present invention, as invented to solve the object of the present invention, is characterised in comprising a saddle for seating a user and supported by a base unit, and a load generating means for imposing a load on both legs, wherein the load generating means comprises a step for holding each foot, with the user being seated and a hip joint and a knee joint being in flexion, and a driving unit for displacing the step from behind a trunk of the user diagonally down to a front thereof, such that the hip joint and the knee joint are substantially concurrently shifted from flexion to extension and at the same time an ankle joint is shifted from dorsiflexion to plantarflexion.
Preferably, in this constitution, the driving unit is arranged to displace the step in a clockwise direction along an arc. In this case, the hip joint angle is brought into near-extension by designing the bottommost position of the step to locate substantially right below the saddle during the exercises . It should be noted that the clockwise exercises allow the hip joint, knee joint and ankle joint to move principally from the start of the exercises. With regard to the movement of leg joints and leg muscles, their motions are substantially equivalent to those observed in uphill walking or stair climbing particularly in the backward exercise mode.
The above leg bending exercise apparatus of the present inventionenablesbendingexercisesequivalent to uphill walking or stair climbing. Besides, as a user is seated on a saddle, the muscular exercises merely require conversion of potential energy into kinetic energy at the leg muscles. Now that a physical strength for supporting the body is unnecessary, an exercise endurance property can be achieved.
As the most relaxed leg bending exercises for human beings, the present invention has taken special notice of an exercise mode according to which uphill walking or stair climbing is performed in the backward direction. The present invention utilises this exercise mode for the following reasons.

According to the sports medicine, the most efficient health exercise is an exercise which employs the maximum amount of muscles within the threshold of aerobic exercises, one of such exercises being exercises of the whole body. In regard to antigravity exercises, the exercise level is maximised when a greater potential energy is converted into kinetic energy, one of such exercises being stair climbing.
Nevertheless, typical stair climbing is likely to be exhausting and turn to anoxic exercises. This is because stair climbing does not make much use of flexors which exhibit the greatest force among the muscles employed at the start of motions: In conse-quence, except for exceptionally tough persons, the muscles are exhausted so severely that the threshold of aerobic exercises is exceeded in a short period. On the other hand, backward stair climbing employs almost all flexors from the start of motions, whereby the exercises can be continued substantially infinitely in an aerobic state with minimum muscle exhaustion, just as normal walking.
These two exercise modes, i.e. stair climbing in the forward direction and in the backward direction are compared in terms of the kinetic momentum. Both exercises have the same potential energy deriving from the step difference, and hence they have the same kinetic energy converted therefrom. Moreover, strictly speaking, under the same exercise conditions, the kinetic momentum varies in accordance with the speed of motion. Considering that backward stair climbing is less exhausting than forward stair climbing, backward stair climbing can be performed at an over-whelmingly increased speed, thereby to permit a phe-nomenal increase of the actual kinetic momentum. For these reasons, of all aerobic exercises, backward stair climbing provides the maximum level of exercise within the unit time, whereas its degree of exhaustion is almost the same as that of walking.
In another aspect, deterioration of athletic abilities is largely attributable to the deterioration of learning ability of the internuntial motoneurons locating at the lateral horn of the spinal column, irrespective of the age. The most effective method for the recovery of the deteriorated athletic abilities is to perform ordinary actions in a completely reverse way.
In other words, the reverse exercise means to perform a reverse action using the same reflection arc (under the polysynaptic kinetic reflex). According to this theory, backward stair climbing is the maximum-level exercise also in terms of the recovery of athletic abilities.
Based on these theories, we analyse the bending exercises of leg joints effected by the leg bending exercise apparatus of the present invention in terms of the dynamics and the exercise physiology. The exercises concurrently employ the hip j oint, the knee joint and the ankle joint, during which the hip joint and the knee joint are substantially concurrently shifted from flexion to extension and the ankle joint is shifted from dorsiflexion to plantarflexion. Thus, such exercises constitute the most desirable exercise mode. Besides, the present invention achieves an exercise endurance property by installing a saddle which helps to save the physical strength for supporting the body. Further, the force of kicking the ground or stairs is regarded as an essential element for the bending exercises of leg joints, the force being intensified or weakened by the kinetic stroke of the leg exercises and the exercise load deriving from the lower thigh.
As has been explained, the bending exercises by means of the leg bending exercise apparatus employ more muscles principally, thereby moving respective joints principally. Such exercises are most desirable, be-cause the exercise load is imposed not locally but evenly on leg muscles and joints.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is an entire perspective view showing an embodiment of the present invention.
Fig. 2 is a view showing the embodiment of the present invention of Fig. 1 in use.
Fig. 3 is an explanatory view showing the motion according to the embodiment of the present invention of Fig. 1.
Fig. 4 is an entire perspective view showing another embodiment of the present invention.
Fig. 5 is a view taken in the direction of arrow X of Fig. 4.
Fig. 6 is a view taken in the direction of arrow Y of Fig. 4.
Fig. 7 is a view taken in the direction of arrow Z of Fig. 4.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present inven-tion are described with reference to the drawings.
Fig. 1 is an entire perspective view showing an embodiment of the present invention. Fig. 2 is a view showing the embodiment of Fig. 1 in use.

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A height-adjustable saddle mount 2a is provided on a pedestal-form base unit 1 via a saddle post 6 upwardly extending therefrom. A saddle 2 for seating a user H rests on the saddle mount 2a via a coil spring 2b. A pair of handles 4a, 4b for supporting the trunk of the user H are disposed on the right and left of the saddle mount 2a. The backside of the trunk of the user H is to be supported by a backrest 5 provided at the back of the saddle mount 2a. The saddle post 6 is formed with a plurality of screw holes 6b and can be adjusted to a desired height by inserting a height adjustment screw 6a through a spigot lc to a desired screw hole 6b. By this adjustment, the height of the saddle 2 is adjusted in accordance with the height of the user and the length of his legs.
On each side of the base unit 1, there is provided a pedal 3 for holding each foot such that the hip joint and the knee joint are in flexion. A strap 3a is attached on each pedal 3 in order to prevent the foot from slipping off from the pedal 3 and secure the foot thereon during the exercises . The base unit 1 is loaded therein with a pedal driving unit 7 which provides exercises of substantially concurrently shifting the hip joint and the knee joint from flexion to extension and at the same time shifting the ankle joint from dorsiflexion to plantarflexion such that the ankle j oint is displaced from behind the centre of the trunk He of the user H diagonally down to a front thereof.
The pedal driving unit 7 is comprised of a mechanism for guiding the pedal 3 via a pedal frame 3b in a clockwise direction along an arc, arranged to follow the respective foot action with the use of a brake or the like, such that when one foot effects a downward stroke, the other foot is raised to the initial position for effecting the next downward stroke, and provided with a drive source for supplying a driving force to these mechanisms. These mechanism permits free and appropriate setting of the kinetic stroke and exercise load of the leg exercise, according to the user's requirements.
Referring to Fig. 3, description is made of the motion observed in the embodiment of the present invention shown in Fig. 1. With the user H seated on the saddle 2, the pedal 3 is positioned to be in unforced contact with the foot, with the hip joint angle B 1 being set within 45° which is in less acute flexion and the knee j oint angle 8 Z being held in near-neutral ( in the neighbourhood of 90°). The user H rests the foot on the pedal 3 and effects a downward stroke of the pedal 3. owing to the pedal driving unit 7 which displaces the pedal 3 in a clockwise direction along an arc-like track m from a position behind the centre of the trunk He diagonally down to a front thereof, the hip joint of the user H shifts from less acute flexion to extension, and the knee joint angle 92 of the knee joint shifts to extension in an unforced manner. At the same time, the ankle joint moves and shifts from dorsiflexion to plantarflexion. In a series of above motions, a downward stroke of the pedal 3 corresponds to the kinetic stroke. As for the arrangement of returning the pedal 3 to the initial position to take the original position, the return may be effected by an automatic return means or by the physical strength of the exercising person. As described above, the essence of the present embodiment is to shift the hip joint of the user H from less acute flexion to extension when the above-mentioned kinetic stroke brings the pedal 3 to the bottommost position P1 or substantially right below the saddle 2 . At that moment, the knee j oint only needs to form a relaxed angle depending on the muscular strength or the range of joint motion of the user H, which means the knee joint is not necessarily brought into near-extension.
In this embodiment, the pedal 3 is designed to move in the clockwise direction, based on the essential v requirement of the dynamics. The bending exercises in this embodiment are intended to employ more muscles principally and thereby to move respective joints principally. Such exercises are most desirable, be-cause the load is imposed not locally but generally and evenly on leg muscles and leg joints. The reason is explained in more detail, taking counterclockwise exercises using a bicycle ergometer as an example.
Even if the pedal is provided at a similar position to the present embodiment, the exercises mainly employ the muscles at the lower thigh, to which the principal muscular strength corresponds. Since the femur is moved subordinately, the exercises of the femur muscular strength are considerably limited, in which case neither the back femur (hamstring group) nor the front femur (quadriceps femoris muscle) can work principally. As a result, force generation is pre-vented in the muscles constituting the enteric and lumbar part which muscles are essential in the hip joint bending exercises. From the viewpoint of motion analysis, the exercises are virtually bending exercises of a knee joint. Even when the hip joint is in extension, the hip joint remains almost free from a principal load during the exercises. Such exercises never provide the effect of the concurrent or combined joint bending exercises of the hip joint and the knee joint as achieved in the present embodiment.
Another embodiment is illustrated in Fig. 4 as a perspective view thereof, in Fig. 5 as a view taken in the direction of arrow X of Fig. 4, in Fig. 6 as a view taken in the direction of arrow Y of Fig. 4, and in Fig. 7 as a view taken in the direction of arrow Z
of Fig. 4. The detail of the embodiment is hereinafter described.
The exercise apparatus of this embodiment com-prises a support frame 11 and a base unit 10 supported on the support frame 11. A saddle post 18 extends arcuately from the rear portion of the base unit 10.
The saddle post 18 is fitted with a saddle height adjustment screw rod 12a for adjusting the height position of the saddle 12 and equipped with a saddle locking handle 12b for locking the saddle 12 at a desired height position. They serve to lock the saddle 12 at a desired height position. Besides, a handle 14 is equipped at the front portion of the base unit 10 for supporting the trunk of the user, and a load adjustment handle 15 for adjusting an exercise load is positioned beneath the handle 14. With the operation of the load adjustment handle 15, a brake unit 20 is driven via a load adjustment wire 19. Under an adjusted load, v pedals 13a, 13b disposed on each side of the base unit are arranged to be driven through a pedal driving unit 21. In addition, at the front central part of the handle, there is provided a timer for clocking the 5 exercise time or a counter for displaying the amount of exercise, so that the user can read it while seated on the saddle.
The thus structured exercise apparatus of the other embodiment allows the user to move the pedals 13a, 10 13b in a relaxed posture as seated on the saddle 12, without forcing a stiff leg posture. This embodiment ensures similar exercises with an equal action and effect, as is the case with the first embodiment. The explanation therefor is the same and omitted herein to avoid redundancy.
The above-explained embodiments may be modified to apply a plain mechanism which merely comprises a unit for effecting downward pedal strokes, thus simplifying the structure of the apparatus.
In the above-explained embodiments, the pedal driving unit is designed for cooperative two-leg strokes effected by both legs pedalling .down one after another. Alternatively, for example, the unit may be designed for single-leg strokes effected by the same one leg or alternating legs with the use of a spring, or simultaneous two-leg strokes effected by both legs pedalling down simultaneously. It goes Without saying that the pedal driving unit may include other known devices utilised in this kind of exercise apparatus such as weight rubber, wire rope, air cylinder, etc.
Furthermore, the front of the trunk may be supported by a board, pat, etc. so as to reinforce the support of the trunk during the exercises.
INDUSTRIAL APPLICABILITY
The seat-type leg bending exercise apparatus of the present invention is advantageous in providing bending exercises equivalent to uphill walking or stair climbing, and, as used in a posture seated on a saddle, also advantageous in enabling even frail persons such as handicapped or aged persons to. perform antigravity exercises without imposing a burden on joints and the like nor raising the heart rate, while ensuring a considerable amount of exercise. It is further advantageous in effectively promoting the recovery of athletic abilities as well as walking ability. The exercise apparatus of the present invention is embodied by a plain mechanism including a unit for effecting downward pedal strokes. The apparatus of remarkably simple structure hence reduces the production cost and exhibits excellent economic performance.

Claims (2)

1. A seat-type leg bending exercise apparatus comprising a saddle for seating a user and supported by a base unit, and a load generating means for imposing a load on both legs, wherein the load generating means comprises a step for holding each foot, with the user being seated and a hip joint and a knee joint being in flexion, and a driving unit for displacing the step from behind a trunk of the user diagonally down to a front thereof, such that the hip joint and the knee joint are substantially concurrently shifted from flexion to extension and at the same time an ankle joint is shifted from dorsiflexion to plantarflexion.

2. A seat-type leg bending exercise apparatus according to claim 1, wherein the driving unit displaces the step in a clockwise direction along an arc.