Hand exerciser

A hand exerciser includes a frame having a contoured hand grip portion and a slide mechanism supported within the frame for reciprocative movement. The slide mechanism includes a transverse finger grip which is both rotatable and angled to maximize the contact area between the palm of the hand and the finger grip. Springs are positioned between the frame and the slide mechanism to provide the resistive force necessary. The resistive force may be adjusted by a single internally threaded knob which cooperates with an externally threaded fastening element between the frame and the slide mechanism. A mechanical counter is coupled to the frame and is engaged by the slide element for the purpose of counting the number of strokes. Also provided is a pointer and scale mechanism for indicating the amount of resistive force provided by the springs.

BACKGROUND OF THE INVENTION 
Field of the Invention 
This invention relates generally to an apparatus for exercising the hand or 
fingers and, more particularly, to a hand exerciser which is anatomically, 
physiologically, and functionally correct. It is well known that after 
injury to an upper extremity, it is often necessary to immobilize the hand 
for a period of several days or perhaps several weeks. During this time, 
as a result, a patient may loose strength in the upper extremity due not 
only to the injury or surgery, but also due to the atrophy accompanying 
immobilization of the extremity. When the patient is first allowed to 
engage in resistive exercise, his grip strength may be less than one 
pound. However, much greater strength is required for the patient to be 
able to return to his vocational or avocational activities. 
Studies of the hand have shown that a finger is fully flexed by the flexor 
digitorum profundus and the extensor digitorum communis. Additionally, 
when resistance is added, the flexor digitorum superficialis, the 
interossei and the intrinsics of the thumb are also activated. Therefore, 
by using a resistive exercising device, many muscles are forced to 
function. It has also been shown that the extensor digitorum communis, the 
flexor digitorum superficialis and the flexor digitorum profundus perform 
in direct proportion to the external load applied. Therefore, any hand 
exerciser employed should provide for increasing resistance. 
Many hand exercising devices are known. Exemplary are the devices shown and 
described in U.S. Pat. Nos. 689,652; 756,480; 3,216,259; 3,357,702; 
4,226,412; and Re. 28,845. Unfortunately, each of the devices suffers from 
one or more of the following disadvantages. First, the contact area 
between the palm of the hand and the grip of the device should be 
maximized in order to decrease the pressure in the thumb web space. This 
generally requires a contoured grip which fits along the curve of the 
oppositional crease, and one which is slightly convex so as to rest in the 
concavity of the palm formed by the transverse metacarpal arch. Many of 
the known devices do not include such a grip. 
Second, the transverse portion of the exerciser which is actually engaged 
by the fingers and compressed toward the grip should be angled so as to 
conform to the hand. The transverse palmar axis passes along a line from 
the second to the fifth metacarpal heads. This forms an angle of 
approximately 75 degrees with the axis of the third ray. Furthermore, by 
angling the transverse mechanism, the fourth and fifth digits assist in 
initiating flexion. This is significant since the fourth and fifth digits 
are primarily responsible for power gripping in normal hands. Most of the 
known devices do not include such an angled transverse mechanism. 
Third, the prior art devices do not include means for conveniently altering 
the stroke distance of the device so as to accommodate hands of different 
sizes nor do they provide a transverse mechanism which is not only angled 
but also rotatably mounted. The rolling feature created along with the 
ability to change the stroke distance of the transverse mechanism provides 
for complete flexion of the digits, thus permitting complete joint range 
of motion and full tendon excursion. These two factors are necessary for 
normal hand functioning. 
Fourth, the prior art devices do not include means associated with the 
transverse portion of the exerciser that compensate for the different 
lengths of the fingers that grip the transverse portion. The middle and 
last two fingers have different lengths, therefore, it is necessary to 
provide a transverse portion of the exerciser that will accomodate and 
compensate for the differing lengths of these three fingers. 
Finally, it is very important that the amount of resistance presented by 
the device be capable of being varied. It is especially important that 
this be easily accomplished with one hand during the early stages of hand 
rehabilatation. Such adjustments are difficult in the prior art devices. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an improved hand 
exerciser. 
It is a further object of the present invention to provide an improved hand 
exerciser wherein the hand grip is contoured to maximize contact area 
between the palm of the hand and the hand grip. 
It is a still further object of the invention to provide an improved hand 
exerciser wherein the transverse mechanism which is compressed by the hand 
is not only angled to conform to the hand so as to maximize its 
rehabilitative effect, but is also shaped to compensate for the different 
lengths of the fingers that grip the transverse portion and is rotatably 
mounted so as to permit complete flexion of the digits, complete joint 
range of motion and full tendon excursion. 
It is another object of the present invention to provide an improved hand 
exercise apparatus wherein the stroke distance is easily varied so as to 
accommodate hands of different sizes. 
Yet another object of the present invention is to provide an improved hand 
exerciser wherein the resistive force provided by the apparatus may be 
easily varied. 
In accordance with one embodiment of this invention, a hand exerciser is 
provided having a frame with a contoured hand grip portion and a slide 
mechanism supported within the frame for reciprocative movement. The slide 
mechanism includes a transverse finger grip which is both rotatable and 
angled to maximize the contact area between the palm of the hand and the 
finger grip. Springs are positioned between the frame and the slide 
mechanism to provide the resistive force necessary. The resistive force 
may be adjusted by a single internally threaded unit which cooperates with 
an externally threaded fastening element between the frame and the slide 
mechanism. A mechanical counter is coupled to the frame and is engaged by 
the slide element for the purpose of counting the number of strokes. Also 
provided is a pointer and scale mechanism for indicating the amount of 
resistive force provided by the springs. 
The above and other objects, features and advantages of the present 
invention will be more clearly understood from the following detailed 
description taken in conjunction with the acocmpanying drawings, in which:

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 to 6, the inventive hand exerciser comprises a 
generally rectangular and hollow frame or handle section 10 having a 
contoured convex hand grip portion 12, a channeled slide mechanism 14 
having a first wall 16 and a second wall 18, and an insert assembly 20 
having a width which permits it to be inserted between walls 16 and 18 of 
slide mechanism 14. 
Upper and lower channel sections 22 and 24 of slide mechanism 14 are 
equipped with base sections 26 and 28 respectively each of which have a 
plurality of apertures 30 and 32 respectively therein. A transverse finger 
grip member 34 having a longitudinal bore 36 therethrough is positioned on 
mounting rod 38. The diameter of bore 36 is larger than the diameter of 
rod 38 so as to permit finger grip 34 to freely rotate on mounting rod 38. 
After finger grip 34 is positioned on mounting rod 38, the lower 
protruding end of rod 38 is positioned in one of the plurality of 
apertures 32 in slide mechanism 14. The upper protruding end of rod 38 is 
positioned in one of the apertures 30 in slide mechanism 14. By properly 
choosing which of apertures 30 and 32 mounting rod 38 is positioned in, 
the angle of transverse finger grip 34 can be varied so as to maximize the 
rehabilitated effect of the exerciser. Furthermore, the stroke distance of 
the device may be varied by choosing a different pair of apertures 30 and 
32 which is closer to or farther from grip 12. Choosing the correct 
stroking distance and permitting transverse finger grip 34 to rotate 
provides for complete joint range of motion and full tendon excursion. 
First and second spring mounting rods 40 and 42 each have first 
terminations 44 and 46 respectively which are inserted into and received 
by receiving cylinders 48 and 50, respectively which are fixedly coupled 
to or formed integrally with frame 10. Springs 52 and 54 (preferably 
compression springs where the desired compression depends on the selected 
thickness of the wire of the spring and the type of wire material) are 
inserted over spring mounting rods 40 and 42 respectively. The remaining 
ends of spring mounting rods 40 and 42 are then inserted through apertures 
56 and 58 in a front portion of insert assembly 20. 
An externally threaded fastening member 60 having a widened head portion 62 
is then inserted through an aperture 64 in slide mechanism 14 and exits 
through an aperture 66 in insert assembly 20. An internally threaded 
adjusting knob 68 threadably engages that portion of fastening 60 which 
protrudes from aperture 66. Thus, the further knob 68 is threaded onto 
fastening 60, the more springs 52 and 54 will be compressed. Thus, the 
user will have to exert greater force to squeeze the transverse finger 
grip 34 and hand grip 12 towards each other. The effort required may be 
easily adjusted by turning adjusting knob 68 in an appropriate direction. 
As can be seen, insert assembly 20 is provided with indicia thereon which 
cooperates with a pointed portion 70 on wall 16. Point 70 cooperates with 
the indicia on insert assembly 20 to serve as a measure of the amount of 
force that will be necessary to compress the exercise apparatus. A ratchet 
type mechanical counter assembly 72 is employed and coupled on frame 10 to 
serve as a measure of the number of times the exercise apparatus is 
compressed. As can be seen, counter 72 includes first and second ratchet 
wheels 74 and 76 respectively each of which may be accessed by knobs 78 
and 80, respectively. A counter cover 82 is provided with a slotted 
opening therein through which knobs 78 and 80 will protrude to provide the 
user access. The counter assembly is shown in more detail in FIG. 6. Such 
ratchet type counter assemblies are well known and reference is made to 
U.S. Pat. Nos. 3,807,729 and 4,262,898. 
As can be seen, the inventive hand exercise apparatus includes a contoured 
hand grip to increase contact between the grip and the palm of the hand 
being exercised. This, as stated previously, decreases the pressure in the 
thumb web space. Furthermore, transverse rod 38 may be angled to maximize 
the rehabilitative effect of the device. This transverse rod is preferably 
spaced on an angle of approximately 75 degrees. Transverse finger grip 34 
is rotatably mounted on rod 38 to provide complete flexion of the digits, 
complete joint range of motion and full tendon excursion. Furthermore, the 
stroke distance of the device may be altered to accommodate hands of 
different sizes by simply choosing a different set of apertures 30 and 32 
in which transverse finger grip 34 is mounted. Finally, the resistive 
force of the device may be easily adjusted with one hand by simply turning 
adjusting knob 68 and altering the degree of compression of springs 52 and 
54. 
The exercise apparatus described above is suitable for use by a patient 
from the beginning of resistive exercises, through the rehabilatative 
process, and can still serve as a valuable exercise device when recovery 
is complete. The level of resistance offered by the device can be simply 
varied via adjusting knob 68, and can have even a broader range by simply 
replacing springs 52 and 54 with springs having different compression 
rates. Counter 72 records the number of complete strokes that the patient 
performs which is very important to a patient following an exact 
prescribed force of treatment. 
Referring to FIG. 7 which is a view similar to FIG. 1, like reference 
numerals depict the same or corresponding parts of this preferred hand 
exerciser apparatus. The preferred hand exerciser embodiment of FIG. 7 is 
even more adaptable for use than the embodiment of FIG. 1 because of the 
unique contour or shape of transverse finger grip member 34A. As can be 
seen with reference to FIG. 7, transverse finger grip member 34A has a 
bulge portion which is an integral part of the transverse finger grip 
member 34A. The portion of the transverse finger grip member 34A is 
tapered inwardly from the bulge portion so that the different sizes of the 
middle and the last two fingers of a person's hand can be better fit or 
accomodated by means of the bulge portion for the longer middle finger and 
the inwardly tapered portion below the bulge portion for the gradually 
smaller sizes of the bottom or last two fingers. Thus, this hand exerciser 
apparatus of FIG. 7 is better anatomically than the embodiment of FIG. 1 
and also provides a better fit, fill or skeletal match for the arch shape 
of the hand and the differing finger sizes. 
The above description is given by way of example only. Changes in form and 
details may be made by one skilled in the art without departing from the 
scope of the invention as defined by the appended claims.