Patent Description:
Massage therapists, sports trainers and chiropractors are now using various types of reciprocating motors driving variously shaped tools that contact the patient's body to provide treatment, alignment adjustment, muscle relaxation, massage, pain relief and other therapies. Reciprocating motors for these devices have included using springs, electric solenoids, rotating motors with eccentric weights, rotating motors driving reciprocating rods with direct linkages such as cams and cranks, and fluid driven pistons. Since the development and mass production of electric and battery powered carpentry jigsaws, these reciprocating motors are being converted for use as therapy devices by replacing the saw blade with a body contact tool. Common with current reciprocating therapy devices is a body contact tool that is rigidly attached to a reciprocating rod driven by a reciprocating motor. Prior art has referred to body contact tools as impact heads, plungers, massage heads, massage fingers, and hitting pads. Body contact tools include differing shapes, sizes and materials of construction. To reduce impact force and pain some body contact tools are made of soft foam rubber or have spring buffers. Miller, <CIT>, discloses different impact heads attached to a reciprocating rod using a coupler that is pinned "so as to prevent rotation of the impact head. " These types of devices with body contact tools connected at a fixed angle to the reciprocating rod are effective but have a small body surface contact area when applied at an angle or they must be applied at a specific angle to the body surface, usually perpendicular, to distribute forces applied to the body over a larger surface area. Small tool contact areas can be useful for some types of therapy but can cause pain and bruising and may not penetrate to deeper tissues and structures. Body contact tools acting perpendicular to the body surface, when used with a reciprocating motor that has a stroke exceeding <NUM>/<NUM> inches, often provide too much motion and impact for delicate patients, sensitive joints, sore muscles and tender body tissues. Documents <CIT> as well as <CIT> also disclose massage systems.

For better treatment during body massage, an improved massage tool is needed to overcome the aforesaid problems.

The present invention provides a massage tool for attachment to a reciprocating motor, such as a hand-held motor of a general size and form as those used for power jigsaws or for known hand-held reciprocating power massage tools. The invention includes a rod and a body follower having a proximal side and a distal side. The rod has a proximal end and a distal end, wherein the proximal end of the rod is configured for attachment to the reciprocating motor. The reciprocating motor has a stroke axis and a stroke length, and the distal end of the rod is configured to rotatably attach to the proximal side of the body follower by means of a rotating joint. The rotating joint defines a center of rotation for the rod as it rotates with respect to the body follower. The distal side of the body follower has a body contact area that has a maximum length at least three times greater than a minimum distance from the center of rotation of the rotating joint to the body contact area, and at least three times greater than the stroke length of the reciprocating motor. In another embodiment, the rotating joint is configured to allow the distal side of the body follower to remain parallel with the surface of the patient's body as the angle of the stroke axis with respect to the body contact area is varied by the operator from about <NUM> degrees to less than about <NUM> degrees.

Various alternative embodiments of the invention provide a swiveled coupling between the rod and the body follower, to allow an operator to translate the body follower around and against the contact area of a patient's body with six degrees of freedom. The massage tool is preferably configured for hand-held operation that allows an operator to freely position and move the body follower against the contours of a patient's body, apply and adjust force applied through the body contact area to the surface of the patient's body, and vary an angle of the stroke axis with respect to the body contact area. Preferably, the body contact area comprises a surface that curves in the proximal direction, allowing the body follower to slide along the surface of the patient's body while reciprocating against the surface of the patient's body without binding or gouging.

Various alternative embodiments of structure for coupling the rod to the reciprocating shaft are also disclosed. The rod may be removably couplable to the reciprocating shaft by keyless friction-fit, or by threaded engagement. Various alternative embodiments of swivel structures are also disclosed that permit the body follower to rotate in either of two orthogonal axes about the distal end of the rod. These structures include rotating joints formed as specialized ball and socket joints, hinges, gimbals, universal joints, flexures, and combinations of the foregoing. In one embodiment, the rotating joint includes a flexure that allows the angle of the stroke axis with respect to the body contact area to be varied by the operator from about <NUM> degrees to less than about <NUM> degrees. In another embodiment, flexure comprises a flexible portion and an inflexible portion. In more elaborate embodiments, a massage tool according to the invention includes a body follower having a distal side configured with a plurality of body contacting nubbins or flexible bristles.

In another embodiment, a massage tool according to the invention includes a rod having a plurality of distal ends, wherein each distal end is attached to a respective one of a plurality of body followers. The plurality of body followers may be symmetrically disposed about a plane passing through the stroke axis, and the rod may include a swiveling joint that allows the plurality of distal ends to rotate about the stroke axis.

Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the invention. Dimensions disclosed or shown are exemplary only. In the drawings, like reference numerals may designate like parts throughout the different views, wherein:.

The following disclosure presents an engineered design for a massage tool for attachment to a reciprocating motor. The reciprocating motor is preferably encased in a chassis, similar to that of a hand-held power jigsaw or hand-held reciprocating power massagers. The massage tool of the present invention is designed to be lightweight and easily removably coupled to a reciprocating shaft of the reciprocating motor, to facilitate manual operation. Preferably, the distal end of the massage tool forms a body follower that may be contoured and/or constructed from a firm but resilient material for comfortable engagement against various surfaces of a human body. A massage tool according to the present invention also preferably features one or more body followers that are coupled to one of various different types a rotatable rods, to enable a user to urge the body follower against and around the contours of the human body with six degrees of freedom.

Several illustrative embodiments of the invention are now disclosed with reference to the accompanying figures. To facilitate understanding, reference is made herein throughout to an operator and a patient; however these terms are not to be interpreted in a limiting sense. The operator is a person handling the massage tool, and may be a professional health care provider such as a chiropractor or massage therapist, or anyone else. The patient is the person whose body is engaged by the body follower of the massage tool when in use by an operator. The patient need not be someone in need of health care, as the invention may have non-medical uses that are purely recreational or relaxational. The operator and the patient may be one and the same; for example, the invention may be designed such that an operator of the massage tool may use it to massage his or her own neck, legs, or lower back.

<FIG> shows a side view of a massage tool <NUM> according to one embodiment of the invention. The illustration shows massage tool <NUM> coupled to a hand-held reciprocating motor <NUM> in a state of use, being manipulated by the left hand of an operator <NUM> grasping the tool at its proximal end. The reciprocating motor <NUM> has a reciprocating shaft <NUM> which is shown in two positions 17A and 17B. The massage tool <NUM> also includes a rod <NUM> having a proximal end <NUM> and a distal end <NUM>, and a body follower <NUM> having a proximal side <NUM> and a distal side <NUM>. The reciprocating shaft <NUM> moves along a stroke axis <NUM> and has a stroke length <NUM>. The stroke length <NUM> of the reciprocating shaft <NUM> is the distance between a fully retracted position 17A and a fully extended position 17B. The massage tool <NUM> is shown connected to the reciprocating shaft <NUM> at the extended position 17B. The proximal end <NUM> of rod <NUM> is removably coupled to the reciprocating shaft <NUM> allowing the massage tool <NUM> to be removed and replaced, preferably by hand without the use of a tool. The distal end <NUM> of rod <NUM> connects to the proximal side <NUM> the body follower <NUM> through a rotating joint <NUM> that has a center of rotation <NUM>. The rotating joint <NUM> may take on many different forms, as will be disclosed further on herein. The distal side <NUM> of body follower <NUM> acts on a contact area on a surface <NUM> of a patient's body <NUM>. During operation, the contact area on the surface <NUM> may vary in both location and size as the body follower <NUM> is moved against and around the patient's body while maintaining contact therewith. However, a design basis for a massage tool according to the invention defines the body contact area <NUM> (<FIG>) as that portion of the overall area of the distal side <NUM> that is substantially parallel to a horizontal plane, i.e., wherein a line tangent to the curvature of distal side <NUM> is less than or equal to about <NUM> degrees with respect to the horizontal plane. When sufficient force is applied to the body follower <NUM> against a relatively large area of a patient's body (e.g., an area greater than body contact area <NUM>, such as an upper thigh or lower back region) to press substantially all of the distal side <NUM> of the body follower against the contact area of the patient's body, the contact area on surface <NUM> and the body contact area <NUM> are substantially the same area.

The configuration of the massage tool <NUM> by which it couples to the reciprocating shaft <NUM> and to the rotating joint <NUM>, which is in turn rotatably coupled to the body follower <NUM>, allows the operator <NUM> to manipulate the position of the body follower <NUM> with six degrees of freedom. For example, the operator <NUM> may adjust the force applied to the body follower <NUM> against the patient's body and the angle <NUM> of the stroke axis <NUM> with respect to the body contact area <NUM>. The rotating joint <NUM> allows the distal side <NUM> of the body follower <NUM> to remain aligned with the surface of the patient's body when the complementary angle of the stroke axis <NUM> is reduced from <NUM> degrees to less than <NUM> degrees, which causes the body follower <NUM> to slide along the surface of the patient's body. As depicted in <FIG>, the angle <NUM> is about <NUM> degrees, and its complementary angle, that is, the angle of the stroke axis <NUM> with respect to the surface of the patient's body, is about <NUM> degrees.

To allow the body follower <NUM> to be more easily translated along the surface of the patient's body, its distal side <NUM> may have a curved or contoured shape <NUM> so that it will tend to slide on, as it reciprocates against, the surface of the patient's body. Preferably, the contoured shape <NUM> is concave, when viewed from the perspective of <FIG>; that is, the curvature of the body follower from its center toward its perimeter turns only toward the proximal direction. According to one embodiment of the invention, for the body follower <NUM> to slide freely along the surface of the patient's body without tipping or gouging an edge, the body contact area <NUM> may have a maximum length about three times greater than a minimum distance <NUM> from the center of rotation <NUM> of the rotating joint <NUM> to the body contact area <NUM>. In addition, the maximum length of the body contact area <NUM> may be at least two times greater than the stroke length <NUM> of the reciprocating shaft <NUM>.

<FIG> is a top view of massage tool <NUM>, as seen from the proximal end of the tool looking toward the distal end of the tool. This figure defines a section A-A that provides a reference for several alternative embodiments <NUM>, <NUM>, <NUM> and <NUM> of a massage tool according to the invention, each varying somewhat in the design of a means for removably coupling the massage tool to the shaft <NUM> of a reciprocating motor <NUM>.

<FIG> shows a cross-sectional view of a massage tool <NUM>, taken along section A-A of <FIG>. Massage tool <NUM> provides a means for removably coupling the rod <NUM> to the reciprocating shaft <NUM>. In this embodiment, rod <NUM> includes a hollow channel sized to accommodate shaft <NUM>. The shaft <NUM> has an o-ring <NUM> installed in a groove cut circumferentially into the shaft. When coupling the rod <NUM> to the shaft <NUM>, and operator forces the rod <NUM> by hand onto the shaft <NUM>, and the o-ring <NUM> provides friction sufficient to maintain engagement of the shaft within the rod during operation of the massage tool.

<FIG> shows a cross-sectional view of a massage tool <NUM>, taken along section A-A of <FIG>. Massage tool <NUM> provides an alternative means for removably coupling the rod <NUM> to the reciprocating shaft <NUM>. In this embodiment, shaft <NUM> includes a hollow channel sized to accommodate the rod <NUM>. O-ring <NUM> is installed in a circumferential groove that is formed on the rod <NUM>. When coupling the rod <NUM> to the shaft <NUM>, and operator forces the rod by hand into the shaft <NUM>, and the o-ring <NUM> provides friction sufficient to maintain engagement of the rod within the shaft during operation of the massage tool.

<FIG> is a cross-sectional view of a massage tool <NUM>, taken nominally along section A-A of <FIG> for ease of illustration. Massage tool <NUM> represents a third embodiment of a means for removably coupling the rod <NUM> to a reciprocating shaft <NUM>. Here, the rod <NUM> and shaft <NUM> are manually threadably engageable and disengageable by a set of mating threads <NUM>. In this embodiment, the threads on rod <NUM> are formed as a female complement to male threads formed on shaft <NUM>.

<FIG> is a cross-sectional view of a massage tool <NUM>, taken nominally along section A-A of <FIG> for ease of illustration. Massage tool <NUM> is a fourth embodiment of a means for removably coupling the rod <NUM> to a reciprocating shaft <NUM>, which is also effected by threaded engagement. The threaded engagement is similar to that of massage tool <NUM>, except that the threads on rod <NUM> are formed as a male complement to female threads formed on shaft <NUM>.

<FIG> is a top view of the proximal side of another embodiment according to the invention of a massage tool <NUM>. Massage tool <NUM> has a rotating joint formed as a ball and socket joint <NUM> on the proximal side of a circular body follower <NUM>. This figure defines a section B-B that provides a reference for several alternative embodiments <NUM>, <NUM>, <NUM>, and <NUM> of a massage tool according to the invention, each varying somewhat in the design of the rotating joint <NUM>.

<FIG> is a cross-sectional view of massage tool <NUM>, taken along section B-B. The socket portion of the joint <NUM> is formed on the proximal side <NUM> of the body follower <NUM>, and is preferably centrally placed thereon, as shown. Other embodiments of a massage tool are possible within the scope of the claims wherein the socket portion is formed on body follower <NUM> off-center. The ball portion of the joint <NUM> is formed on the distal end <NUM> of the rod <NUM>. In this view, the rod <NUM> is shown aligned with the centerline of the figure and substantially perpendicular to the body contact area on the distal side <NUM> of the body follower <NUM>. In operation, the rod <NUM> may be rotated with respect to the body contact area <NUM> about either of two orthogonal axes by an angle in the range of about <NUM> to <NUM> degrees from the vertical centerline. In another embodiment, the range of that angle may be about <NUM> to <NUM> degrees.

<FIG> is an elevation view of the massage tool <NUM>, showing the center of rotation of the rotating joint <NUM> at the intersection of the centerlines. In this embodiment, the body contact area <NUM> on the distal side <NUM> of the body follower may be formed as a spherical section.

<FIG> is a cross-sectional view of another embodiment of a massage tool <NUM> of the present invention. The cross-sectional view is taken nominally along section B-B of <FIG> for ease of illustration. Massage tool <NUM> has a rotating joint formed as a ball and socket joint <NUM> on the proximal side of a circular or oblong body follower <NUM>. In this embodiment, the ball and socket joint <NUM> is reversed from that of <FIG>, with the ball portion being a part of and extending proximally from the body follower, and with the socket portion being formed on the distal end of the rod <NUM>. This arrangement provides a range of angular rotation of the rod <NUM> with respect to the body contact area <NUM> of the body follower about two orthogonal axes, similar to the mechanics of massage tool <NUM>.

<FIG> is a cross-sectional view of another embodiment of a massage tool <NUM> of the present invention. The cross-sectional view is taken nominally across section B-B of <FIG> for ease of illustration. Massage tool <NUM> features a rotating joint formed as a ball and socket joint <NUM> on the proximal side of a circular or oblong body follower <NUM>. A flexible cushion or rubber o-ring <NUM> is positioned between the body follower <NUM> and the ball portion of joint <NUM>. Depending on the materials used to form massage tool <NUM>, it may be desirable to include item <NUM> within the joint assembly to provide sufficient friction during rotation of the ball to enable the rod <NUM> to maintain a desired angular position with respect to the body follower when the rod is under force of gravity alone, or in combination with the force of the reciprocating shaft <NUM>. At the same time, item <NUM> should be selected to limit the rotational friction of the ball within the socket to enable the operator to rotate the body follower without undue difficulty.

<FIG> is a cross-sectional view of another embodiment of a massage tool <NUM> of the present invention. The cross section is taken nominally across section B-B of <FIG> for ease of illustration. Massage tool <NUM> also has a rotating joint formed as a ball and socket joint <NUM> on the proximal side of a circular or oblong body follower <NUM>. Massage tool <NUM> is simplified by providing a hollow void <NUM> in the socket portion of joint <NUM>, without including a cushion or o-ring. This embodiment is suitable where certain plastic or elastomeric materials are used to form the joint <NUM>.

<FIG> is an elevation view of another embodiment of a massage tool <NUM> according to the invention. Massage tool <NUM> features a ball and socket joint <NUM>, wherein the socket portion is formed as a spherical enclosure having a rod slot <NUM> cut circumferentially along its centerline, as shown. The rod slot <NUM> allows the rod <NUM> to rotate further than the range of rotation provided by massage tools <NUM> or <NUM>, as depicted in <FIG> and <FIG>. With this alternate configuration, an operator using massage tool <NUM> can reduce the angle of the stroke axis with respect to the body contact area to about <NUM> degrees to provide a more gentle massage.

<FIG> show an embodiment of a massage tool <NUM> according to the invention that is characterized by a rotating joint having a swivel and hinge. <FIG> is a top view of massage tool <NUM>, <FIG> is a side view thereof, and <FIG> is a cross-sectional view thereof taken along section C-C of <FIG>. The rotating joint of massage tool <NUM> has a hinge <NUM> formed on the proximal side <NUM> of a circular body follower <NUM>. The body follower <NUM> has a dish-like shape, as the round section of a sphere, with rounded edges <NUM> formed on the distal side <NUM> and two hinge brackets <NUM> mounted on the proximal side <NUM>. The distal end <NUM> of the rod <NUM> is cylindrical in form, with ends that fit between the hinge brackets <NUM> and that define a hole to accept a hinge pin <NUM>. The proximal end <NUM> of the rod <NUM> has an o-ring <NUM> set into a groove similar to the arrangement shown in <FIG>. The rod <NUM> is bifurcated and configured as a swivel <NUM> with a swivel retaining shaft <NUM>. Action of the swivel <NUM> allows the body follower <NUM> to rotate around the axis of the rod <NUM>, as the rod rotates about the hinge pin, so that an operator can translate the body follower against and along a contact area of a patient with six degrees of freedom.

<FIG> show an embodiment of a massage tool <NUM> according to the invention that is characterized as having a rotating joint in the form of a swivel and a hinge on the proximal side of an oblong body follower. <FIG> is a top view of massage tool <NUM>, <FIG> is a side view thereof, and <FIG> is a cross-sectional view thereof taken along section D-D of <FIG>. The proximal side of massage tool <NUM> includes a hinge <NUM> with a hinge pin <NUM> to form part of the rotating joint. The body follower <NUM> has the shape of an oblong section of a cylinder having rounded edges on the distal side <NUM> and a hinge bracket <NUM> formed on the proximal side <NUM>. The distal end <NUM> of the rod <NUM> forms a yoke <NUM> having two ends fitting against each side of the hinge bracket <NUM> and a hole defined through all to accept the hinge pin <NUM>. The proximal end <NUM> of the rod <NUM> has an o-ring <NUM> installed within a groove for connection in the manner previously shown in <FIG>. The yoke <NUM> forms a distal portion of rod <NUM> and is connected to the proximal portion of rod <NUM> by a retaining swivel shaft <NUM>. This arrangement allows the body follower to swivel by rotating about the axis of the rod while also rotating about hinge pin <NUM>, to maintain the body contact area <NUM> of the body follower engaged with the contact area of the patient's body.

<FIG> show an embodiment of a massage tool <NUM> according to the invention that is characterized by having a rotating joint formed as a universal joint on the proximal side of a body follower, and by having a body follower that is formed as an circular section of a sphere having rounded edges on its distal side. <FIG> is a top view of the proximal side of massage tool <NUM>, <FIG> is a side view thereof, <FIG> is another side view thereof displaced by <NUM> degrees from the side view of <FIG> is an alternate side view thereof wherein the rod is rotated with the cross axle showing the rod partially rotated on both axes. On massage tool <NUM>, the rotating joint is formed as a universal joint <NUM> having a hinge pin <NUM> and a cross axle <NUM>. The body follower <NUM> has a dish-like shape, as a round section of a sphere, with rounded edges on the distal side <NUM> and two hinge brackets <NUM> formed on the proximal side <NUM>. The distal end <NUM> of the rod <NUM> includes a yoke <NUM> having two ends fitting against each side of the cross axle <NUM> and a hole defined through all to accept the hinge pin <NUM>. The proximal end <NUM> of the rod <NUM> has an o-ring <NUM> installed within a groove cut into the rod <NUM> for connection as previously shown and described in <FIG>. The universal joint of massage tool <NUM> allows an operator to move the body follower with six degrees of freedom, and in particular, to rotate the body follower about two orthogonal axes so that the body contact area <NUM> can remain aligned with the contact area of the patient's body as the body follower glides across varying contours of the patient's body. In one embodiment, beginning at the center of the distal side of the body follower and moving outward toward the perimeter, the contour of the body follower including the rounded edges curve in the proximal direction to provide easy translation across the patient's body and to avoid catching an edge or gouging the patient.

<FIG> shows a top view of another embodiment according to the invention of a massage tool <NUM> having a rotating joint formed as a flexure joint <NUM> on the proximal side <NUM> of a body follower <NUM>. The body follower <NUM> has a dish-like shape, formed as a round section of a sphere, having rounded edges on its distal side <NUM>. Flexure joint <NUM> may comprise a flexure, or a flexible rod having a similar cross-sectional area as rod <NUM>, and may be bonded, as shown, or fastened to the distal end <NUM> of the rod <NUM> and to the proximal side <NUM> of the body follower <NUM>. The flexure joint allows the body follower <NUM> to rotate with respect to rod <NUM> and be translated along contours of the patient's body while the body contact area <NUM> remains engaged to the contact area of the patient's body.

<FIG> shows a cross-sectional view of massage tool <NUM> taken along section E-E of <FIG>. This view shows the proximal end <NUM> of the rod <NUM> aligned for coupling to the male end of the reciprocating shaft <NUM>. An o-ring <NUM> may be installed as described in previous embodiments to provide a friction fit between rod and shaft.

<FIG> shows another cross-sectional view of massage tool <NUM>, taken nominally along section E-E for ease of illustration. This view shows the rod <NUM> rotated off the vertical axis. The rotation of the rod <NUM> is made possible by applying sufficient manual force to the flexible joint <NUM>, which is formed from a material having sufficient strength and resilient flexibility to achieve an angle of deflection in a range between <NUM> degrees and about <NUM> degrees, or in other embodiments, between <NUM> degrees and about <NUM> degrees. The angle of deflection <NUM> of the rod <NUM> is with respect to the vertical line <NUM> that passes through an approximate center of rotation of the rod when the rod is in an undeflected state and oriented substantially perpendicular to the body contact area <NUM>. When the manual force is removed, the flexure returns to its undeflected position.

<FIG> shows a cross-sectional view of an embodiment according to the invention of a massage tool <NUM>. The cross-sectional view is taken nominally along section E-E of <FIG> for ease of illustration. Massage tool <NUM> provides another implementation of a flexible joint. In this case, the flexible joint is formed by mounting a specialized flexure <NUM> to the proximal side <NUM> of the body follower <NUM>. Flexure <NUM> is formed from strong, resilient, flexible material and includes a receptacle <NUM> that is sized to accept and frictionally engage with the distal end of the rod <NUM>. Flexure <NUM> may be bonded or fastened to, or formed integrally with, the proximal side <NUM> of the body follower. In one embodiment, flexure <NUM> includes a flexible portion and an inflexible portion. For example, the flexible portion may be located at the proximal end of the flexure, which the inflexible end may be located at the distal end of the flexure to provide a rigid base for coupling to the distal side of the body follower. In one embodiment, the flexible portion and inflexible portion are made from different materials, e.g. rubber and metal, respectively. In another embodiment, the material of flexure <NUM> is homogeneous, with flexible and inflexible portions determined by material thickness. The proximal end <NUM> of the rod <NUM> may have an o-ring <NUM> installed in a groove cut into the rod as shown and described in previous embodiments.

<FIG> shows a cross-sectional view of massage tool <NUM>, showing the flexure joint implementation with the rod <NUM> rotated off the vertical axis. The cross-sectional view is taken nominally along section E-E of <FIG> for ease of illustration. This view shows a position of the rod <NUM>, deflected off vertical by manual force, to form an angle <NUM> of about <NUM> degrees as shown between an axial line <NUM> running through the rod and a vertical line <NUM>. In one embodiment, the massage tool <NUM> with flexure <NUM> is configured to allow angle <NUM> to span a range from about <NUM> degrees to about <NUM> degrees. In another embodiment, the angular range spans from <NUM> degrees to about <NUM> degrees. When the manual force is removed, flexure <NUM> will spring-return to its undeflected position represented by the vertical line <NUM> that passes through an approximate center of rotation and that is substantially perpendicular to the body contact area <NUM>.

<FIG> show alternative embodiments for the configuration of the body contact area of a massage tool according to the invention. <FIG> is a magnified cross-sectional view of one such embodiment configured with a plurality of body contacting nubbins <NUM> formed on the distal side <NUM> of a body follower <NUM>. Nubbins <NUM> extend generally perpendicularly from distal side <NUM>, and may have rounded ends separated by a distance approximately equal to the length of nubbin protrusion. Other embodiments are possible in which the size and pattern of nubbins may vary. <FIG> is a magnified cross-sectional view of another such embodiment configured as a brush having flexible bristles displaced evenly along the curved surface of the distal side <NUM> of a body follower <NUM>. Nubbins <NUM> and bristles <NUM> provide an operator with the ability to stimulate the muscles of a patient in different ways.

<FIG> shows a side view of another embodiment according to the invention of a massage tool <NUM>. Massage tool <NUM> is characterized as having a rod <NUM> configured for engagement to a reciprocating shaft <NUM>, and having a plurality of distal ends <NUM> coupled to a respective plurality of body followers <NUM>. The body followers <NUM> may be symmetrically disposed about a plane <NUM> passing through the stroke axis <NUM>. A swivel <NUM> formed in the rod <NUM> allows the plurality of body followers <NUM> to rotate about the stroke axis. In this embodiment the proximal end <NUM> of the rod <NUM> is configured to be removably coupled to the reciprocating shaft <NUM>, by means of a friction fit provided by an o-ring <NUM> installed in a groove cut into the rod as shown and described in previous embodiments herein. The body followers thus configured will independently remain in contact with, and aligned with a body surface <NUM>, at multiple different contact areas, such as on a patient's thigh as shown in the figure. While tool <NUM> is depicted with two body followers <NUM>, other embodiments having more than two body followers are possible within the scope of the claims. According to the invention, where multiple body followers are installed on a single massage tool, it is especially beneficial to construct the body contact areas <NUM> so that they curve in a proximal direction, as described in previous embodiments, to allow the tool be freely translated over irregular contours of the patient's body. Curvature of body followers in the opposite or distal direction, e.g., that mimic curvature of the patient's body, may cause a massage tool with multiple such body followers to mis-engage with or gouge the patient's skin as the tool is moved along the surface of the patient's body.

As for materials of construction, the major components of a massage tool <NUM> may be manufactured from stout materials such as certain metals, plastics, elastomers, and woods. For example, body followers may be formed from ABS plastic or synthetic rubber. Rods and balls may be machined from acetyl, nylon, or injection-moldable plastic, or may be formed from steel or aluminum. Branch arms may be machined from ABS plastic or acetyl bar stock. Smaller components such as connectors or fasteners between ball and rod, hinge pins, and swivel shafts may be machined from aluminum or steel. O-rings are preferably synthetic rubber such as neoprene or Viton™. Flexures may also be formed from a synthetic rubber, or from a thermoplastic such as polyurethane, or from a metal coil spring. Adapters needed for coupling the massage tool to jigsaws or other reciprocating motors may be machined from rugged materials, e.g., acetyl, steel, and aluminum. For mass production, a majority of the components may be manufactured from plastics, either by injection molding, heat-forming, or machining.

Claim 1:
A hand-held massaging system for reciprocating against a body surface, comprising:
a reciprocating motor having a reciprocating shaft having a single stroke axis and a stroke length;
a body follower having a proximal side and a distal side;
a rod having a proximal end removably coupled to the reciprocating shaft to maintain the rod in axial alignment therewith, and a distal end configured to (i) rotatably attach to the proximal side of the body follower by means of a rotating joint that defines a center of rotation, and (ii) allow an angle of the stroke axis with respect to the body surface to vary while reciprocating the body follower along the stroke axis and against the body surface; and
a swivel on the stroke axis allowing the body follower to turn about the stroke axis and to reciprocate along the stroke axis;
the distal side of the body follower having a body contact area and having a maximum length at least three times greater than a minimum distance from the center of rotation of the rotating joint to the distal side of the body follower.