Abstract:
Current resistance strength-training machines for humans that use structural links and hinges to transfer resistance to muscles constrain the resisted range of motions of the bones of the body&#39;s limbs and trunk at their skeletal joints to one rotational degree of freedom. Alternatively, current strength-training cable-and-pulley machines limit biomechanical movements to two rotational axes against vector-resultant resistance. Unconstrained, the humerus, for example, rotates at its shoulder joint in three directions: pitch, yaw, and roll. Similarly, the radius and ulna can rotate at their elbow joint in two directions: pitch and roll. This invention creates a class of resistance strength-training machines that will provide greater efficiency and effectiveness during exercise by allowing the simultaneous combination of any pair of, or all of, pitch, yaw, and roll motions, each resisted separately, of a single bone or group of bones, such as the vertebrae, primarily about a connected, projected, or virtual skeletal joint.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable  
       DESCRIPTION OF ATTACHED APPENDIX  
       [0003]     Not Applicable  
       FIELD OF THE INVENTION  
       [0004]     This invention relates generally to the field of exercise equipment and more specifically to apparatus for human strength-training.  
       BACKGROUND OF THE INVENTION  
       [0005]     Resistance strength training exercises for the muscles of the human body typically require their repeated contraction and extension through relative motions of the skeletal bones and joints. Commonly understood terms for describing skeletal joints include such terms as shoulder joint, elbow joint, wrist joint, hip joint, knee joint, ankle joint, etc. Other types of joints would include those of the spinal column that allow it to bend and twist as a whole, or locally at individual vertebra or at the neck for example.  
         [0006]     Anatomically, joints such as the elbow joint actually consist of several joints to allow flexion and extension of the forearm as well as pronation and supination of the hand. However from a simplified mechanical perspective the forearm, which consists of the radius and ulna, may be considered able to rotate separately or simultaneously in two directions, pitch and roll, about the elbow joint; that is, about a connected, projected, or virtual point. Similarly, other joints may be viewed in this manner. For example, the humerus about its shoulder joint and the femur about its hip joint can each rotate separately or simultaneously in three directions, pitch, yaw, and roll. A more complex example would be the spinal column which consists of a series of vertebrae whose cumulative rotational and translational motions about their proximate joints allow it to bend and twist. Still, from the mechanical perspective, the spine, in one case, may be considered a column that can not only bend but pitch, yaw, and roll separately or simultaneously generally about a point near the pelvis. In another case, to describe the motions at the neck, the spine may be considered as a series of independent links separated by bearings that allow pitching, yawing, and rolling of the head about a point between the shoulders.  
         [0007]     The concept of this invention is based upon this simplified mechanical perspective of skeletal bones and joints. Particularly, complex localized skeletal joints are considered as a single joint that allows only rotational motions, while bones are considered to rotate about axes that converge at a point within or near a skeletal joint. In reality the axes of rotation may not converge to a single point; however, the intent of the aforementioned mechanical perspective is to approximate and simplify.  
         [0008]     Hence, this invention is intended to provide strength-training efficiency and effectiveness by both allowing and resisting independently the simultaneous paired or triple combinations of pitch, yaw, and roll motions of a bone, or group of bones, about a single virtual skeletal joint. The motions of the machine are independent in that each motion requires of the user an applied dynamic force or moment to the machine that is neither a vector component nor a vector resultant of another respective dynamic force or moment along or about an orthogonal, or virtually orthogonal, axis of mechanical motion. Accordingly, each biomechanical rotation at a skeletal joint may be performed individually without performing another skeletal rotation about an orthogonal axis at that skeletal joint and without feeling resistance about another axis at that skeletal joint. So, for example, by using the invention the user may pitch a skeletal bone about its skeletal joint without incurring a concomitant yaw or roll motion or resistance about either of those axes. Therefore each of the mechanical movements of the machine and each of the corresponding biomechanical rotations at a skeletal joint may be accomplished individually or simultaneously at the discretion of the user.  
         [0009]     In its various embodiments this invention will allow the aforementioned paired or triple combinations of skeletal rotations at individual virtual skeletal joints typically by combinations of a set of mechanical joints. Those joints may be of various types, such as bushings, radial bearings, angular contact bearings, hinges, thrust bearings, spherical bearings, linear or curvilinear slide bearings, etc. They may also be oriented along mutually orthogonal axes or have vector components along such axes or have a permutation thereof.  
         [0010]     For the purpose of strength-training this invention must not only allow the aforementioned skeletal rotations to occur independently, but it must also provide resistance to all of these motions independently. Separate and simultaneous resistance to these combined rotations may occur through passive means and may be constant or variable depending upon the preferred embodiment. Examples of passive means would include weights, deflection beams, helical springs, friction devices, etc. Passive constant loads can be achieved with weights and pulley systems, counter-weighted levers, constant-force springs, etc. Variable passive loads can be achieved by cams incorporated into a system of weights and pulley, or by helical springs, variable friction devices, etc. Examples of active resistance, whether constant or variable, can be achieved by pneumatic, hydraulic, motor, brake, electromagnetic, or other means, perhaps in conjunction with electronic controllers.  
         [0011]     The resistance to motion about each skeletal joint need not be from a single shared source. That is, separate and independent sources of resistance might be applied to resist each motion. This would allow the selection of different loads, all available to be applied simultaneously and, as before, independently in resistance against their designated motions. Also, if the resistance should instead originate from a common source it need not provide a common torque around each axis of a skeletal joint. In this case, some embodiments of this concept would impose different amounts of resistance torque about each rotational axis of a skeletal joint. This might result from mechanical or biomechanical geometry.  
         [0012]     Regardless of the means of resistance, the essential concept is to provide it individually to simultaneous rotations of a bone, or group of bones, whether attached to one another or separated by other skeletal joints, about a single connected, projected, or virtual point that may be considered as a single biomechanical joint of the skeleton. The benefit of this is not only that two or more normally separate exercises can instead be performed at one time, but that muscle groups may be developed more comprehensively and effectively through simultaneous resistance, not a force vector component or resultant, about multiple rotational axes and through extensive ranges of motion. Such benefits have long been recognized, though restricted by inertial physics and ergonomic constraints in their implementation, through user adaptations with free weights.  
         [0013]     Resistance strength-training machines for humans have used a variety of means to transfer resistance to motions of the body and thereby facilitate the development of muscles through their repeated contractions and extensions. Some devices employ the body weight of the user for resistance. Others are simply free weights that provide resistance to motions of the user by gravity and by their rotational inertia. Still others are mechanisms that employ either passive or active means to achieve the said resistance. The means of resistance and the means of transferring resistance are extensive within the prior technology.  
         [0014]     Many varieties of mechanisms exist to provide resistance to specific motions of the user. Those that use structural beams, or links, and mechanical joints are typically designed to provide resistance to rotation of a bone, or group of bones, about a theoretically single body joint, or axis of rotation, of said bone or bones. Accordingly they provide resistance to flexion and extension of muscles about a single axis of rotation of the body or its appendages through a single axis of rotation or translation of the machine. Many examples and embodiments of this exist, including but not limited to those used for the development of the biceps, triceps, deltoids, pectorals, trapezoids, latimus dorsi, abdominals, quadriceps, calves, gluteus, etc.  
         [0015]     Some varieties of resistance strength-training machines employ pulleys and cables without lever arms and hinge bearings. These are intended to provide greater freedom of movement and therefore other forms of exercises.  
         [0016]     Apparatus or devices that employ the body weight of the user as resistance against body motions occur in many varieties. Examples include chin-up bars, parallel dip bars, leg-raise platforms, inclined sliding mechanisms with cables and handles, etc. All of these are intended to develop a primary muscle group, or group of muscles, through resistance intended primarily to be transferred to one rotational axis, or sometimes a sequence of rotational axes, of the skeleton on each side of the body.  
         [0017]     Alternatively, free weights that may be held or attached to a limb of the body do not prevent the normal rotations of skeletal bones, or group of bones, about their joints. However, their resistance to motions comes in two distinct and widely variant forms, their gravitational weight and their rotational inertia. Hence, the user may select a suitable weight for flexion and extension yet find it inadequate in rotational inertia for simultaneously-performed twisting motions, that is, roll motions about the axis of the skeletal bone. Although such commercial weights among the various manufacturers may incidentally vary somewhat in geometry relevant to rotational inertia, their geometry is always ultimately constrained by the ergonomics of body movements.  
         [0018]     Mechanisms that transfer resistance to body motions through other means may also have limitations similar to the devices described above. For example, a common machine for exercising the biceps uses a handle, lever, and radial bearing with a pulley and cable system to transfer resistance from a set of weights. Sometimes a cam may also be used to facilitate ergonomics. Nevertheless, such a machine restricts motion of the forearm to rotation about a single axis, namely a pitch axis, of the elbow joint, through rotation of the machine lever about a single machine joint.  
         [0019]     Another mechanism used for development of the biceps is a cable and pulley system that links a handle to a set of weights. The user grasps a handle in one or both hands and performs flexion to lift the weights and extension to lower the weight. If the machine has a handle designed for one hand, then the user may pronate and supinate the hand during the extension and flexion. However, resistance to pronation and supination would be unintended by the design, slight, and non-adjustable, as it would result merely from twisting of the cable and any incidental friction at the pulley.  
         [0020]     The closest approximation to the concept of this invention is a pulley and cable mechanism intended for development of the triceps. With palms down and either standing or supine, the user holds the handle at about elbow level and extends the forearms to lift the weights. If the handle is rigid the user cannot supinate and pronate the hands during the extension and flexion movements. However, if the handle is a flexible tensile element, such as a rope, the user may also supinate and pronate simultaneously with extension and flexion. This, however, may be an adaptaption of this configuration by users because its purpose may instead be targeted toward extensions coupled with lateral, or outward, movements rather than pronation and supination movements of the hands. If the user chooses to pronate and supinate the hands during the extension and flexion motions the rope will tend to wrap around each side of the hands near the forefinger and thumb. This user adaptation would provide two degrees of skeletal rotational resistance simultaneously about a virtual single skeletal joint. However, because the axis of rotation of the skeletal bone would have a vector component perpendicular to the cable, a concomitant pitching and yawing resistance would result about the said skeletal joint. Hence, although the skeletal rotations and resistance occur simultaneously, they cannot each occur independently. Specifically, pronation and supination of the hands would require rotation of the forearm, consisting of the radius and ulna, through an applied torque combined with lateral and vertical force vectors. Also, as a user adaptation, this said exercise is uncomfortable and abrasive to the hand.  
         [0021]     Other approximations to the concept of this invention include a pulley and cable mechanism that is used to exercise the pectorals. Such systems consist of two opposing pulleys that are mounted on spindles to the floor or an attached framework. With arms extended laterally and downward the user must pull diagonally upwardly and inwardly to lift the weights. This would necessitate rotation of each arm at its shoulder joint in two directions: pitch and yaw. Such machines are designed to allow freedom of movement and will provide a single resistance against two rotations at a skeletal joint. But such machines are specifically designed for, and therefore are restricted to, providing only one load common to each rotational axis at a skeletal joint. That is, because of the vectorial nature of the single cable such that there is a single line of force acting along the axis of the said cable, they do not completely isolate the resistance to motion about each rotational axis at the skeletal joint about more than one axis at a time. A simple cable and pulley arrangement will either provide resistance to rotation about one skeletal axis or it will provide simultaneous, but not independent resistance to rotation about orthogonal axes at a skeletal joint. In the former case the cable must be in the plane of the skeletal motion of the user. In the latter case the cable will be at an angle to the plane of the skeletal motion of the user such that any single motion incurs another or incurs a force or moment from another plane or axis. Hence, any pair of rotations of a skeletal joint cannot be performed separately and distinctly during the exercise and without reconfiguring the apparatus between the different exercises. Additionally, limited by the underlying concept of their invention, such machines cannot provide an intended resistance about a third orthogonal axis of rotation. A cable, which is a tensile element, cannot provide intended resistance about its own axis.  
         [0022]     Instead, this invention is intended specifically, not by user adaptation, to allow the user to rotate a bone, or group of bones, about a connected, projected, or virtual skeletal joint simultaneously, separately, and distinctly against one or more resistance loads about two or more virtually perpendicular axes. Furthermore, this invention is also not intended strictly to increase freedom of movement up to two rotational degrees of freedom with a common resistance as the aforementioned pulley and cable systems do. Rather, in some embodiments this invention will allow and resist separately three independent degrees of freedom in rotation about a skeletal joint. And in other embodiments this invention will provide different amounts of resistance torque from a single source of loading to each of two or more rotational axes of a skeletal joint. And in still other embodiments, this invention can provide selectable amounts of resistance torque from multiple sources of loads for two or more rotational axes of a skeletal joint. So, for a given exercise, although there may exist an ideal combination of simultaneous biomechanical motions, the user can always choose which of two or more skeletal rotations to make about a single skeletal joint, when to make it, or whether to make it at all. And in yet other embodiments, this invention may incorporate guides that constrain the user to an ideal motion path that requires the combination of two or more rotational motions of the skeletal bone about its respective joint. However, in all its embodiments this invention provides for a minimum of two independent rotations of a skeletal bone, or group of bones, at its/their skeletal joint against resistance, that is neither a force or moment vector component nor resultant of another applied force or moment, around each axis of the skeletal joint.  
         [0023]     This invention provides the user greater efficiency during an exercise period because it can reduce what would normally require two or three separate exercises to a single exercise. Additionally, in some cases, this invention will provide new capabilities and benefits in exercise. For example, during a biceps exercise the user would be resisting one or more adjustable loads affecting each rotational axis simultaneously yet separately. Further benefits might also accrue from the greater range of muscle movement and from the simultaneous performance of the two or three rotational motions of the skeletal bone. Hence, the invention would allow exercise that is more comprehensive in recruiting and extending muscle groups simultaneously. In its various embodiments, similar capabilities and benefits would apply to different muscles and muscle groups.  
       BRIEF SUMMARY OF THE INVENTION  
       [0024]     The primary object (advantage) of the invention is to provide humans with resistance strength-training machines that allow, yet can resist severally, two or more simultaneous independent multidirectional rotations of a skeletal bone, or group of bones, of a limb or the spine primarily about a single connected, projected, or virtual skeletal joint.  
         [0025]     Another object (advantage) of the invention is to provide humans with resistance strength-training machines that reduce the need for separate exercises by increasing freedom of movement and therefore allowing more complex body motions.  
         [0026]     A further object (advantage) of the invention is to provide humans with resistance strength-training machines that enhance the development of a targeted muscle, or muscle group, by allowing and resisting more complex, multidirectional, skeletal motions severally.  
         [0027]     Yet another object (advantage) of the invention is to provide humans with resistance strength-training machines that enhance the development of a targeted muscle, or muscle group, by allowing and resisting a more extensive range of motion.  
         [0028]     Still yet another object (advantage) of the invention is to provide humans with resistance strength-training machines that may also recruit muscle groups that are complementary or supplementary to the targeted muscle group.  
         [0029]     Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.  
         [0030]     In accordance with the concept of the invention, there is disclosed a class of resistance human strength-training exercise apparatus that separately allows and resists, neither as a force or moment vector component nor as a resultant, the simultaneous combination or sequence of two or more independent motions of pitch, yaw, or roll of a skeletal bone, or group of bones, of one limb of, or of the trunk or neck of the human body primarily about a single connected, projected, or virtual skeletal joint.  
         [0031]     Various embodiments may include: a structural framework that mounts to, or rests upon, the floor; and one or more mechanical rotation joints and structural links that are supported by the structural framework; and adjustable constant or variable, shared or distributed resistance to rotation of the machine joints through passive means, such as by weights, friction, or magnetic effects, or active means, as by powered devices to allow the human user to rotate the machine joints against the said resistance.  
         [0032]     Furthermore, the embodiments may include a first mechanical rotation joint or functionally-equivalent linear, or planar-curvilinear, mechanical translation joint(s) whose respective axis/axes of rotation or linear or planar-curvilinear translation is/are in a first direction; and  
         [0033]     a mechanism to allow one skeletal bone, or group of bones, of a human limb or trunk to rotate about its, or their, connected, projected, or virtual skeletal joint in a first motion whose axis of rotation is parallel to, or has a vector component parallel to, the axis of rotation of the first mechanical rotation joint or perpendicular to, or projected-perpendicular to, the axis of translation of an alternative first functionally-equivalent translation joint(s) or perpendicular to, or projected-perpendicular to, a tangent to the planar-curvilinear translation of an alternative functionally-equivalent translation joint(s); and  
         [0034]     a second mechanical rotation joint, or secondary function of the first mechanical rotation joint such as that of a spherical bearing, whose axis of rotation is in a direction, possibly projected, perpendicular to, projected-perpendicular to, or with a vector component perpendicular, or projected-perpendicular to, the respective axis of rotation of the first mechanical rotation joint or, for the functionally-equivalent alternative case of a second mechanical linear translation joint(s) with its(their) axis/axes of linear or planar-curvilinear translation parallel, or tangent-parallel, to the axis of the first mechanical rotation joint or perpendicular to, projected-perpendicular to, or tangent-perpendicular to, the axis/axes of motion of the first alternative functionally-equivalent mechanical linear or planar-curvilinear translation joint; and  
         [0035]     a mechanism to allow said bone or bones of said limb or trunk to rotate simultaneously with its/their first skeletal rotational motion about said skeletal joint in a second skeletal motion whose axis of rotation is parallel to, or has a vector component parallel to, the second machine axis of rotation or, for the case of a functionally-equivalent translation joint(s), perpendicular to, or projected-perpendicular to, its/their second machine axis of translation or perpendicular, or projected-perpendicular, to a tangent(s) to its/their second machine axis of planar-curvilinear translation(s); and  
         [0036]     where biomechanically applicable, a third mechanical rotation joint, or tertiary function of the first mechanical rotation joint, such as that of a spherical bearing, whose axis of rotation is in a direction perpendicular to, projected-perpendicular to, or with a vector component perpendicular to, or projected-perpendicular to, the plane or projected plane of said two orthogonal axes of rotation of the said mechanical rotation joints, or for the functionally-equivalent alternative case of a third mechanical linear or planar-curvilinear translation joint, whose axis, or tangent axis, of translation is parallel to the said plane of the perpendicular, or projected-perpendicular, axes of rotation of the said first and second mechanical rotation joints, or perpendicular to, or projected-perpendicular to, the axis of a rotation of a first mechanical rotation joint and parallel to the axis of translation of a second mechanical translation joint; and  
         [0037]     where biomechanically applicable, a mechanism to allow said bone, or bones, of said limb to rotate about said skeletal joint in a third motion whose axis is parallel to, or has a vector component parallel to, the third axis of said mechanical rotation or perpendicular to, or projected-perpendicular to, the third axis of said mechanical translation  
         [0038]     The invention may also include: an integrated or an alternative means to allow simultaneous or sequential rotations of two similar human skeletal bones, or group of bones, of opposing limbs, one on each side of the body, each about its/their respective proximate connected or virtual skeletal joint; and a possible mechanical means to distribute independently or to share mutually all or any sources of rotational resistance, between the two said opposing skeletal bones, or group of bones; and a possible integrated or alternative means to isolate all rotational resistance alternately or exclusively to one or both of said skeletal bones, or group of bones, of said limbs; and a possible means to guide the exercise motion of the user through an ideal path.  
       LISTS  
       [0000]     Qualities &amp; Benefits:  
         [0039]     To provide resistance strength-training machines for humans that allow multidirectional freedom of movement against resistance consistent with, or superior to, free-weight strength training.  
         [0040]     To provide resistance strength-training machines for humans that resist, yet allow, two or more simultaneous independent multidirectional rotations of a skeletal bone of a limb, or of a group of bones, about a single connected, projected, or virtual skeletal joint.  
         [0041]     To provide resistance strength-training machines for humans that allow the user to isolate each applicable skeletal rotation from the other about the same skeletal joint.  
         [0042]     To provide resistance strength-training machines for humans that may allow different quantities of resistance to be applied simultaneously around each axis of rotation of the said skeletal joint.  
         [0043]     To provide resistance strength-raining machines for humans that save the user time by reducing the need for separate exercises.  
         [0044]     To provide resistance strength-training machines for humans that enhance the development of a targeted muscle, or muscle group, by allowing yet resisting complex skeletal motions.  
         [0045]     To provide resistance strength-training machines for humans that enhance the development of a targeted muscle, or muscle group, by allowing and resisting an extensive and multidirectional range of motion.  
         [0046]     To provide resistance strength-training machines for humans that may also recruit muscle groups that are complementary or supplementary to the targeted muscle group.  
         [0047]     Primary Elements:  
         [0048]     A resistance strength-training apparatus for humans that, by use of one or more mechanical bearings, flexures, fluid-filled bladders, or other turnable joints, or a combination of linear or curvilinear guides and turnable joints, allows the simultaneous combination of two or more independent motions of pitch, yaw, and roll of a skeletal bone, or group of bones, against non-interactive resistance about a single connected, projected, or virtual skeletal joint; and  
         [0049]     A resistance strength-training apparatus for humans with a first turnable machine joint or linear guide(s) whose respective axis of rotation or translation is in a first direction; and  
         [0050]     A resistance strength-training apparatus for humans with a mechanism to resist, yet allow one skeletal bone, or group of bones of a limb, or group of bones of the skeletal trunk, to rotate about the aforementioned skeletal joint in a first motion whose axis is parallel to the axis of rotation of the first machine joint; and  
         [0051]     A resistance strength-training apparatus for humans with a second turnable machine joint or linear guide(s) whose respective axis of rotation or translation is in a direction perpendicular, or projected perpendicular to, or with a vector component perpendicular to, or projected perpendicular to the pivot axis of the first machine joint; and  
         [0052]     A resistance strength-training apparatus for humans with a mechanism to resist, yet allow the aforementioned bone or bones of the aforementioned limb or trunk to rotate simultaneously with its first motion about the aforementioned skeletal joint in a second motion whose pivot axis is parallel to the pivot axis of the second machine joint; and  
         [0053]     A resistance strength-training apparatus for humans with a possible third turnable machine joint or linear guide(s) whose respective axis of rotation or translation is perpendicular to, or with a vector component perpendicular to, the plane, or projected plane of the two pivot axes of the aforementioned machine joints; and  
         [0054]     A resistance strength-training apparatus for humans with a possible third provision, or mechanism, to allow the aforementioned bone or bones of the aforementioned limb or trunk to rotate simultaneously about the aforementioned skeletal joint in a third motion whose axis is parallel to the pivot axis of the third machine joint; and  
         [0055]     A resistance strength-training apparatus for humans that, in the case of limbs, and primarily by duplication of design, allows the aforementioned physical motions to occur simultaneously or alternately on each side of the human body for the similar bone or bones of the opposing limb; and  
         [0056]     A resistance strength-training apparatus for humans with handles, levers, bearings, pulleys, and cams as needed that provide the user with freedom of movement against one or more resistance loads in accordance with the particular exercise  
         [0057]     Secondary Elements:  
         [0058]     A structural framework with fastening attachments to mount it to the floor as needed; and  
         [0059]     A structural framework with level adjustability as needed; and  
         [0060]     A structural framework to which are mounted pulleys, cables, levers, links, linkages, and bearing assemblies as needed; and  
         [0061]     A structural framework to which is mounted a means of providing resistance or of transferring resistance to the user; and  
         [0062]     Adjustable, or selectable, resistance to the human user by passive means such as selectable weights, friction or magnetic means, or by active means such as controlled motors, brakes, electromagnetic means, pneumatics, or hydraulics; and  
         [0063]     Handles, levers, cables, linkages, counterweights or other devices to allow the user to rotate his skeletal bone or bones against said resistance; and  
         [0064]     Ergonomic features such as body supports for the seat, back, chest, limbs, joints, or other parts of the body; and  
         [0065]     Integral cams, or other devices, to vary the loading ergonomically along the rotational arcs of exercise motions as needed; and  
         [0066]     Operation and safety instructions to the user on labels mounted to the structural assembly as needed; and  
         [0067]     Journal, radial, and/or spherical bearings as needed; and  
         [0068]     The possible use of free standing weights separately or in combination with weights permanently installed on the framework; and  
         [0069]     The possible use of gearing or power reduction devices; and  
         [0070]     Mechanisms to allow similar motions simultaneously on each side of the body for each similar bone, or group of bones, of a similar limb; and  
         [0071]     Mechanisms to provide a shared resistance, as by a single stack of weights, or to provide separate and independent resistance loads, as by multiple stacks of weights, to each rotational axis; and  
         [0072]     Shields, covers, or guards over pulleys and other potential hand and finger pinch points  
         [0073]     Substitute Elements:  
         [0074]     No Substitute Elements for Primary Element number 1; and  
         [0075]     No Substitute Elements for Primary Element number 2; and  
         [0076]     No Substitute Elements for Primary Element number 3; and  
         [0077]     A spherical turnable machine joint may be used as the first turnable machine joint and therefore also provide, in the same unit, the relative axis geometry of the eliminated second turnable machine joint; and  
         [0078]     A spherical turnable machine joint may be used as the first turnable machine joint and therefore also provide, in the same unit, for the second skeletal motion whose pivot axis is parallel to the pivot axis of the eliminated second machine joint; and  
         [0079]     A spherical turnable machine joint may be used as the first turnable machine joint and therefore also provide, in the same unit, the relative axis geometry of the eliminated third turnable machine joint; and  
         [0080]     A spherical turnable machine joint may be used as the first turnable machine joint and therefore also provide, in the same unit, for the third skeletal motion whose pivot axis is parallel to the pivot axis of the eliminated third machine joint; and  
         [0081]     A resistance strength-training apparatus for humans that, in the case of limbs of the body, and primarily by reduction of design, allows only one side of the human body to be exercised; and  
         [0082]     A resistance strength-training apparatus for humans with handles, levers, bearings, and slots, tracks, rails or other passive or active devices to guide the exercising portion of the body of the user along an ideal motion path 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0083]     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.  
         [0084]      FIG. 1  is a perspective view of a first embodiment of the invention.  
         [0085]      FIG. 2  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 1  with an illustration of the approximate position of the hand and arm at the start of the exercise.  
         [0086]      FIG. 3  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 1  with an illustration of the approximate position of the hand and arm at a secondary stage of the lifting phase of the exercise.  
         [0087]      FIG. 4  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 1  with an illustration of the approximate position of the hand and arm at a third stage of the lifting phase of the exercise.  
         [0088]      FIG. 5  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 1  with an illustration of the approximate position of the hand and arm at the final stage of the lifting phase of the exercise.  
         [0089]      FIG. 6  is a perspective view of a second embodiment of the invention.  
         [0090]      FIG. 7  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 6  with an illustration of the approximate position of the hand and arm at the start of the exercise.  
         [0091]      FIG. 8  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 6  with an illustration of the approximate position of the hand and arm at a secondary stage of the downward pushing phase of the exercise.  
         [0092]      FIG. 9  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 6  with an illustration of the approximate position of the hand and arm at a third stage of the downward pushing phase of the exercise.  
         [0093]      FIG. 10  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 6  with an illustration of the approximate position of the hand and arm at the final stage of the downward pushing phase of the exercise.  
         [0094]      FIG. 11  is a perspective view of a third embodiment of the invention.  
         [0095]      FIG. 12  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 11  with an illustration of the approximate position of the hand, arm, and shoulder at the start of the lifting phase of the exercise.  
         [0096]      FIG. 13  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 11  with an illustration of the approximate position of the hand, arm, and shoulder at a secondary stage of the lifting phase of the exercise.  
         [0097]      FIG. 14  is a magnified perspective view of a portion of the invention shown in the embodiment of  FIG. 11  with an illustration of the approximate position of the hand, arm, and shoulder at the final stage of the lifting phase of the exercise.  
         [0098]      FIG. 15  is a perspective view of the embodiment of the invention, shown in  FIG. 11 , in its secondary stage of the lifting phase of the exercise, subsequent to the position of the machine shown in  FIGS. 11 and 12 , and corresponding with the view shown in  FIG. 13 .  
         [0099]      FIG. 16  is a perspective view of the embodiment of the invention, shown in  FIG. 11 , in its final stage of the lifting phase of the exercise, subsequent to the position of the machine shown in  FIG. 13 , and corresponding with the view shown in  FIG. 14 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0100]     Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.  
         [0101]     In accordance with the present invention for a new class of strength training apparatus for humans,  FIGS. 1, 6 , and  11  are perspective views of various embodiments of the invention. There are many embodiments of this invention that can address many other parts of the human body as well, such as the muscles of the abdominals, back, legs, and neck. Therefore the aforementioned figures are intended only to illustrate the broad applicability of the concept of the invention and emphasize the feasibility and practicality of the invention.  
         [0102]     Turning to  FIG. 1  an embodiment intended primarily for the exercise of the biceps muscles is shown. All of the indicated reference characters of  FIG. 1  identify components and mechanisms that are well known within the industry.  
         [0103]      FIG. 1  shows a new and unique combination of a mechanical system of pulleys, cables, and handles that would provide mechanisms to allow the human user to rotate two mechanical rotation joints independently against resistance. This embodiment would, by virtue of independent mechanical motions, distributed application of resistance, and constrained exercise motion paths, allow and resist, neither as force or moment vector components nor as a vector resultant, two independent simultaneous or sequential rotations of each of two similar human skeletal bone groups, each consisting of the radius and ulna, of opposing limbs, the arms, each primarily about its respective proximate connected or virtual skeletal joint, the elbow joint, against a constant resistance.  
         [0104]     In  FIG. 1 , in which the apparatus is shown in its intended upright orientation, a structural framework, shown by reference character  25 , mounts to, or rests upon the said floor, which would be towards the bottom of the page as seen by looking at  FIG. 1 . Passive adjustable resistance, in the form of weights, is identified by reference character  24 . A first mechanical rotation joint is indicated by reference character  20 . The axis of rotation of said first rotation joint is in a first direction that is approximately parallel to the said floor. A second mechanical rotation joint is indicated by reference character  21 . The axis of rotation of said second mechanical rotation joint is in a second direction that is approximately perpendicular to the axis of the said first mechanical rotation joint.  
         [0105]     In  FIG. 1 , each handle indicated by reference character  22  is attached to the second mechanical rotation joint indicated by reference character  21 . Each of said second mechanical rotation joints is attached to a connecting plate identified by reference character  26 . In turn, each of the said connecting plates is attached to the structural framework identified by reference character  25  through each said first mechanical rotation joint identified by reference character  20 . Rotation of each of the said first mechanical rotation joints, reference character  20 , is independent and mutually exclusive, of rotation of each of the said second mechanical rotation joints, reference character  21 .  
         [0106]     In  FIG. 1 , a system of pulleys and cables, a portion of which is identified by reference character  27 , connects each of the said first mechanical rotation joints to the resistance, in the form of a stack of adjustable, or selectable, weights, identified by reference character  24 . The weights are constrained to vertical movement by each of the guides identified by reference character  28 .  
         [0107]     In  FIG. 1 , the ergonomic supports identified by reference character  23  include a seat, a seatback, and elbow pads. These said ergonomic supports are attached to the structural framework identified by reference character  25 . The arbitrary angles of each of the handles, reference character  22 , and of each of the first and second mechanical rotation joints, reference characters  20  and  21  respectively, do not necessarily represent the ideal ergonomic configuration.  
         [0108]     In  FIG. 1 , the user would be seated with his back against the seatback. Letting his arms hang down, he would place the backs of his elbows against the fronts of the elbow pads. So positioned, his skeletal elbow joints would be nearly aligned with the said first mechanical rotation joints indicated by reference character  20 . He would then rotate his hands so that, looking down from the user&#39;s perspective, his right hand would rotate counterclockwise and his left hand would rotate clockwise. The rotation of each hand would continue until the user would be able to grasp each handle shown in reference character  22 . This embodiment is symmetric about the vertical mid-plane and therefore the approximate starting position of only the right hand and arm of the user is illustrated in  FIG. 2 .  
         [0109]      FIGS. 2, 3 ,  4 , and  5  are perspective views of the invention and are each essentially a magnification of the left side of  FIG. 1  with the addition of a sketch of the human arm and hand. These said figures provide illustrations of the arm and hand of the user as the arm progresses through the contraction, or lifting, phase of the exercise. For each biceps muscle, the ideal use of this machine would be for the user to rotate the second mechanical rotation joint, reference character  21 , with the handle, reference character  22 , against the resistance, reference character  24  while nearly simultaneously rotating the said first mechanical rotation joint, reference character  20 . Whether both of these motions could be biomechanically initiated simultaneously would be dependent upon the initial angle of the handle, reference character  22 . Among these said figures it can be seen that the said skeletal elbow joint is progressively bent in a pitch motion while the forearm, consisting of the radius and ulna, is progressively twist about the same skeletal elbow joint in a yaw motion. In  FIG. 2 , the position of the handle, reference character  22 , is assumed to be at zero degrees and the position of the connecting plate, reference character  26 , is also assumed to be at zero degrees. Compared to  FIG. 2 , in  FIG. 3  the position of the said handle has changed by approximately 90 degrees while the position of the said connecting plate has changed by approximately 45 degrees. Compared to  FIG. 2 , in  FIG. 4  the position of the said handle has changed by approximately 180 degrees while the position of the said connecting plate has changed by approximately 90 degrees. Compared to  FIG. 2 , in  FIG. 5  the position of the said handle has changed by approximately 0 degrees while the position of the said connecting plate has changed by approximately 135 degrees.  
         [0110]     As illustrated in  FIGS. 2, 3 ,  4 , and  5  the rotation of the said first mechanical rotation joint occurs by a first rotational motion of the radius and ulna bones at the said skeletal elbow joint. And also in these said figures the rotation of the second mechanical rotation joint occurs by a second and independent rotational motion of the said bones at the same skeletal elbow joint. Hence, the said first rotational motion at the said skeletal elbow joint may be considered a pitching motion and the second rotational motion at the said skeletal elbow joint may be considered a yawing motion. Therefore, this embodiment allows the simultaneous combination of pitch and yaw skeletal motions about a virtual single skeletal joint. Each of these said motions is independent and allowed and resisted separately because neither contributes force or moment vector components or is a resultant such that the motions may be performed separately and distinctly from one another. Because this invention allows independence of the aforementioned pitch and yaw motions and does not provide a guide for the motion path, the user may deviate as desired from the sequence of motions illustrated in  FIGS. 2, 3 ,  4 , and  5 .  
         [0111]     In  FIG. 1 , this embodiment employs a shared resistance, that is, a single stack of weights. This embodiment also allows similar motions simultaneously on each side of the body for each similar bone, or group of bones, of a similar limb. In this embodiment, if the user were to move both of his arms simultaneously, then one of the user&#39;s arms would assist the other against the resistance. However, for each of his arms, the respective pitching and yawing motions of the humerus bone and each resistance thereupon remain mutually exclusive and independent.  
         [0112]     The embodiment shown in  FIG. 1  is primarily intended to employ the biceps muscles which are recruited by each of the aforementioned pitching and yawing motions about the said skeletal elbow joint. In exercise, the simultaneous combination of these said skeletal motions is efficient and provides effective and relatively comprehensive muscular development of the biceps. As a secondary benefit, exercise of supplementary or complementary muscle groups of the arms would also result.  
         [0113]     Turning to  FIG. 6  an embodiment intended primarily for the exercise of the triceps muscles is shown. All of the indicated reference characters of  FIG. 6  identify components and mechanisms that are well known within the industry.  
         [0114]      FIG. 6  shows a new and unique combination of a mechanical system of pulleys, cables (cables not illustrated), and handles that would provide mechanisms to allow the human user to move two mechanical joints independently against resistance. This embodiment would, by virtue of independent mechanical motions, distributed application of resistance, and constrained exercise motion paths, allow and resist, neither with force or moment vector components nor as a resultant, two independent simultaneous or sequential rotations of two similar human skeletal bone groups, the radius and ulna, of opposing limbs, the arms, each primarily about its respective proximate connected or virtual skeletal joint, the elbow, against a constant resistance.  
         [0115]     In  FIG. 6 , in which the apparatus is shown in its intended vertical orientation, a structural framework, shown by reference character  36 , mounts to, or rests upon the floor. As seen by looking at  FIG. 6 , the floor would be towards the bottom of the page. Passive adjustable resistance, in the form of weights, is identified by reference character  35 . A first mechanical translation joint is indicated by reference character  29 . The said translation joint translates along the linear guide identified by reference character  30 . The axis of translation of the said first translation joint is in a first direction that is approximately perpendicular to the said floor. A second mechanical rotation joint is indicated by reference character  31 . The axis of rotation of said second rotation joint is in a second direction that is approximately perpendicular to the axis of the said first translation joint.  
         [0116]     In  FIG. 6 , each handle indicated by reference character  32  is attached to the said second rotation joint indicated by reference character  31 . Each of said rotation joints is attached, directly or indirectly, to a said translation joint identified by reference character  29 . In turn, each of the said translation joints translates along a linear guide identified by reference character  30 . Each of said linear guides, in turn, is attached to the structural framework identified by reference character  36 , which mounts to, or rests upon the said floor. Translation of the said first translation joint, reference character  29 , is independent and mutually exclusive, of rotation of the second rotation joint, reference character  31 .  
         [0117]     In  FIG. 6 , a system of pulleys and cables, a portion of which is identified by reference character  33 , connects each of the said first rotation joints, reference character  31 , and each of the said translation joints, reference character  29 , to the resistance, in the form of a stack of adjustable, or selectable, weights, identified by reference character  35 . The weights are constrained to vertical movement by each of the guides identified by reference character  34 .  
         [0118]     In  FIG. 6  no ergonomic supports other than the aforementioned handles, reference character  32 , are required or identified. The arbitrary angles of each of the handles, reference character  32 , and of each of the second mechanical rotation joints, reference character  31 , and of each of the first mechanical translation joints and their guides, reference characters  29  and  30  respectively, do not necessarily represent the ideal ergonomic configuration.  
         [0119]     In  FIG. 6 , the user would be standing between the two long extensions of the structural framework, reference character  36 , that rest on the said floor, and would be closely facing the apparatus to grasp each handle, reference character  32 . So positioned, the user would be grasping each handle in each of his hands such that each of his forearms, each consisting of the radius and ulna, were at an approximate angle of 45 degrees or less with respect to his vertical trunk and away from his head. This starting position is illustrated in  FIG. 6  and  FIG. 7 . This embodiment is symmetric about the vertical mid-plane and therefore the approximate starting position of only the left hand and arm of the user is illustrated in  FIG. 7 .  
         [0120]      FIGS. 7, 8 ,  9 , and  10  are perspective views of the invention and are each essentially a magnification of the left side of  FIG. 6  with the addition of a sketch of the human arm and hand.  FIG. 7  is the starting position so the illustrated approximate angle of the forearm and hand may therefore be considered each at zero degrees.  
         [0121]     These said figures provide illustrations of the arm and hand of the user as the arm progresses through the extension phase of the exercise. For each triceps muscle, the ideal use of this machine would be for the user to rotate each of his forearms downward from the elbows by pulling downward on each of the said handles, reference character  32 , against the resistance, reference character  35 . By so doing, the user would be producing a pitch motion at each of his skeletal elbow joints and would thereby move each of the said first translation joints, reference character  29 . Though it is neither a goal of the exercise nor is it precluded by the invention, a concomitant pitching of each shoulder joint would occur to allow the skeletal rotation, or pitch motion, about the said skeletal elbow joint in conjunction with the said linear motion of the said first translation joint. He would continue this downward pitching rotation about each of his skeletal elbow joints against resistance, reference character  35 , for a total of about 45 degrees or more from the position illustrated in  FIG. 7  until each of his forearms were approximately perpendicular to his body as illustrated in  FIG. 8 . The user would then continue the said downward pitching rotation of each of his arms thereby further moving each of the said translation joints, reference character  29 , by pushing downward on each of the said handles, reference character  32 , while starting to simultaneously rotate each of the said rotation joints, reference character  31 , with each of the said handles, reference character  32 , against said resistance, reference character  35 , thereby producing a simultaneous roll motion of each forearm of the user about each of his said elbow joints. This is illustrated in  FIG. 9  where the forearm has pitched a total of about 67 degrees and has rolled a total of about 67 degrees when compared to the illustration of the starting position shown in  FIG. 7 . These said simultaneous pitching and rolling motions about the said skeletal elbow joint continue until the forearm has pitched a total of approximately 90 degrees and the hand and forearm have rolled about the said skeletal elbow joint an approximate total of 135 degrees when compared to the illustration of the starting position shown in  FIG. 7 . This final position of the extension phase of the exercise is illustrated in  FIG. 10 .  
         [0122]     As illustrated in  FIGS. 7, 8 ,  9 , and  10  the rotation of the said first mechanical translation joint occurs by a first rotational motion of the said skeletal elbow joint. And also in these said figures the rotation of the second mechanical rotation joint occurs by a second and independent rotational motion of the same skeletal elbow joint. Hence, the said first rotational motion of the said skeletal elbow joint may be considered a pitching motion and the second rotational motion of the said skeletal elbow joint may be considered a rolling motion. Therefore, this embodiment allows the simultaneous combination of isolated pitching and rolling skeletal motions of a single group of bones, the radius and ulna, about a virtual single skeletal joint, the elbow joint. Each of these said motions is resisted separately because neither motion assists the other and because they can be performed distinctly and separately from one another. Hence, for each of his arms, the said respective pitching and rolling motions of the radius and ulna bones and each resistance thereupon remain mutually exclusive and independent. Because this invention allows independence of the aforementioned pitch and roll motions and does not provide a guide for the motion path, the user may deviate as desired from the sequence of motions illustrated in  FIGS. 7, 8 ,  9 , and  10 .  
         [0123]     In  FIG. 6 , this embodiment employs a shared resistance, that is, a single stack of weights. This embodiment also allows similar motions simultaneously on each side of the body for each similar bone, or group of bones, of a similar limb. In this embodiment, if the user were to move both of his arms simultaneously, then one of the user&#39;s arms would assist the other against the resistance. However, for each of his arms, the respective pitching and rolling motions of the humerus bone and each resistance thereupon remain mutually exclusive and independent.  
         [0124]     The embodiment shown in  FIG. 6  is primarily intended to employ the triceps muscles which are recruited by each of the aforementioned pitching and rolling motions about the said skeletal elbow joint. In exercise, the simultaneous combination of these said skeletal motions is efficient and provides effective and relatively comprehensive muscular development of the triceps. As a secondary benefit, exercise of supplementary or complementary muscle groups of the arms would also result.  
         [0125]     Turning to  FIG. 11 , an embodiment intended primarily for the exercise of the deltoids muscles is shown. All of the indicated reference characters of  FIG. 11  identify components and mechanisms that are well known within the industry. In  FIG. 11  duplicate reference characters are omitted because of the obvious symmetry of this embodiment. In  FIG. 11  where an element of the device may be seen one side rather than the other, it is shown with its reference character on that side.  
         [0126]      FIG. 11  shows a new and unique combination of a mechanical system of pulleys, cables, and handles that would provide mechanisms on each side to allow the human user to rotate two mechanical rotation joints and translate one mechanical linear translation joint against resistance. Motion of the said vertical translation joint would be isolated from, and independent of, motions of the said rotations joints. This embodiment, by virtue of independent mechanical motions, distributed application of resistance, and constrained exercise motion paths, would allow and resist two independent simultaneous or sequential rotations of each of two similar human skeletal bones, the humerus, of opposing limbs, the arms, each primarily about its respective proximate connected or virtual skeletal joint, the shoulder joint, against a constant resistance that imparts no force or moment vector components or resultants from each isolated motion about each orthogonal axis of the skeletal joint.  
         [0127]     In  FIG. 11 , in which the apparatus is shown in its intended upright orientation, a structural framework, shown by reference character  47 , mounts to, or rests upon the said floor, which would be towards the bottom of the page. Passive adjustable resistance, in the form of a stack of weights, reference character  45 , are vertically moveable with a pulley and cable system (cables not illustrated), reference character  44 , along each of two guides, reference character  46 . At each side a first mechanical linear translation stage, or joint, assembly is represented by reference character  37 . To each of said translation joint assemblies is attached a first mechanical rotation joint, reference character  38 . The said first mechanical rotation joint is also attached to the first structural connecting arm, reference character  40 , which in turn is connected to the second mechanical rotation joint, reference character  39 . The said second mechanical rotation joint in turn is attached to a second structural connecting arm, reference character  41 , which in turn is connected to the handle assembly, reference character  42 . Though it is not a requirement of the invention, the said handle assembly is shown to pivot independently without resistance about a vertical axis at reference character  43 . Ergonomic supports in the forms of a seat and seatback are shown by reference character  48 . The said seat is connected to the said structural framework, reference character  47 , with a vertically-adjustable telescoping assembly, reference character  49 .  
         [0128]     In  FIG. 11 , the user would be seated with his back against the ergonomic support, the said vertical seatback, reference character  48 , between the two long extensions of the structural framework, reference character  47 , that rest on the said floor. The user would be facing each of the said handles, reference character  42 , and would bend his elbows with his palms facing him to grasp each of the said handles. So positioned, the user would be grasping each handle in each of his hands such that each of his humerus bones were at an approximate angle of 90 with respect to the floor. Therefore each of his humerus bones would be parallel to his vertical spine. This starting position is illustrated in  FIG. 11  and  FIG. 12 . This embodiment is symmetric about the vertical mid-plane and therefore the approximate starting position of only the right hand and arm of the user is illustrated in  FIG. 12 .  
         [0129]      FIGS. 12, 13 ,  14 , are perspective views of the invention and are each essentially a magnification of the left side of  FIG. 1  with the addition of a sketch of the human shoulder, arm, and hand. These said figures provide illustrations of the shoulder, arm, and hand of the user as the arm progresses through the contraction, or lifting, phase of the exercise.  
         [0130]     For each deltoids muscle, the ideal use of this machine would be for the user to rotate each of his humerus bones about their respective shoulder joints simultaneously about two orthogonal axes at each of the said shoulder joints. One of the said two simultaneous skeletal motions would be a pitching motion of each of the humerus bones such that looking from a right side view of  FIG. 11 , each of the humerus bones of the user would move clockwise about each of his shoulder joints. The result of this said pitching motion would be to cause each of the humerus bones to move upward and away from the trunk of the body thereby raising each of the elbows from their starting positions. A second of the said two skeletal motions would be a yawing motion of each of the humerus bones. As seen from the perspective of the user looking down towards the floor, his right humerus would yaw clockwise about his right shoulder joint while his left humerus would yaw counterclockwise about his left shoulder joint.  
         [0131]     Hence,  FIGS. 12, 13 , and  14  illustrate the sequential motions of the skeletal arm and hand throughout the lifting phase of the exercise. From these figures it can be understood that the humerus bone of each arm has rotated simultaneously around two orthogonal axes intersecting at the corresponding shoulder joint. And each of these motions is allowed and resisted separately such that each rotation of the humerus bone about the said two orthogonal axes at the said shoulder joint requires a separate and distinct effort in that direction and no motion assists or results in another such that the skeletal rotations and imposed loads thereupon are isolated from one another.  
         [0132]     The motions of the exercise apparatus as a whole can be understood from  FIGS. 11, 15 , and  16  which show the sequential motions of the machine.  FIG. 11  is the resting, or starting, position of the apparatus.  FIG. 11  corresponds with the said magnification,  FIG. 12 .  FIG. 15  corresponds with the said magnification,  FIG. 13 . In moving from the machine position of  FIG. 11  to the machine position of  FIG. 15  the said connecting arms, reference character  40  and  41 , have each yawed about their respective mechanical rotation joints, reference characters  38  and  39 . In addition, the said connecting arms have translated independently in the vertical direction through translation of the aforementioned translation joint assembly, reference character  37 . The position of the said connecting arms in  FIG. 15  is intermediate between that of  FIG. 11  and that of  FIG. 16 .  FIG. 16  corresponds with the said magnification,  FIG. 14 . In further moving the said connecting arms from their positions shown in  FIG. 15  to their positions shown in  FIG. 16  they each have again yawed about the vertical axes of their respective mechanical rotation joints. Additionally, these said connecting arms have again translated further vertically through motion of each of the said translation joints, reference character  37 . Also, though it is neither a requirement of, nor a contradiction to, the invention, each of the said handles at reference character  43  has pivoted approximately 90 degrees independently, and at the discretion of the user, without resistance around its corresponding vertical axis.  
         [0133]     Because this invention allows independence of the aforementioned pitch and yaw motions of the humerus and does not provide a guide for the motion path, the user may deviate as desired from the sequence of motions illustrated in  FIGS. 11, 12 ,  13 , and  14 .  
         [0134]     In  FIG. 11 , this embodiment employs a shared and constant resistance, that is, a single stack of weights. This embodiment also allows similar motions simultaneously on each side of the body for each similar bone, or group of bones, of a similar limb. In this embodiment, if the user were to move both of his arms simultaneously, then one of the user&#39;s arms would assist the other against the resistance. However, for each of his arms, the respective pitching and yawing motions of the humerus bone and each resistance thereupon remain mutually exclusive and independent.  
         [0135]     The embodiment shown in  FIG. 11  is primarily intended to employ the deltoids muscles which are recruited by each of the aforementioned pitching and yawing motions of the humerus bone about the said skeletal shoulder joint. In exercise, the simultaneous combination of these said skeletal motions is efficient and provides effective and relatively comprehensive muscular development of the deltoids. As a secondary benefit, exercise of supplementary or complementary muscle groups of the arms and upper back would also result.  
         [0136]     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.