1. Field of the Invention
The present invention relates generally to the field of medical devices, and more specifically, to an ergonomic crutch.
2. Description of the Related Art.
Traditional crutches have stationary armpit pads, a hand grip that is vertically aligned with the armpit pad, and no way of adjusting the angle of the hand grip relative to the armpit pad. In an attempt to make crutches more ergonomic, shock absorbers have been incorporated into crutches to generate a more horizontal plane of travel (as opposed to an arc) of the armpit pad when the crutch is in use. Some prior art designs for crutches have incorporated a vertical tilt to the armpit pad itself to provide for a more comfortable fit between the patient's underarm and the armpit pad of the crutch.
In some crutches currently available on the market, the hand grip has been moved from its traditional location inside of the crutch frame to a position outside of the crutch frame and further away from the body. Various accessories, such as crutch pockets and pouch bags, have been added to crutches to make it more convenient for the patient to carry items while using crutches. All of these innovations in crutch design are intended to make crutches easier and more comfortable to use.
None of these prior art crutch designs, however, has solved the particular problem that is addressed by the present invention, and that is, that the angle of a person's palm in relation to the rest of his or her body when the person's arm is allowed to hang freely varies from individual to individual. This problem is solved in the present invention by allowing the armpit pad to swivel horizontally so that the patient can achieve the most comfortable position of the hand grip in relation to the armpit pad.
The present invention also offers the advantage of being collapsible into three pieces, which can be held together with a strap and carried in a stuff bag for easy portability. These and other advantages of the present invention are discussed more fully below.
The present invention is an ergonomic crutch comprising an armpit pad assembly; a top tube; a middle tube; a bottom tube; a hand grip; a shock absorber; and a footpad assembly; the armpit pad assembly comprises an armpit pad and means for allowing the armpit pad to tilt vertically and swivel horizontally; the top tube comprises a top end and a bottom end, and the armpit pad assembly connects to the top end of the top tube; the middle tube comprises a top end and a bottom end; the bottom end of the top tube slides into the top end of the middle tube; the bottom tube comprises a top end and a bottom end; the top end of the bottom tube slides into the bottom end of the middle tube; the hand grip is offset laterally from the middle tube; the shock absorber comprises a barrel and a piston; the barrel of the shock absorber is situated inside of the bottom end of the bottom tube, and the piston of the shock absorber protrudes downward from the bottom end of the bottom tube; the footpad assembly comprises a footpad; the piston of the shock absorber comprises a top end and a bottom end; and the bottom end of the piston of the shock absorber connects to the footpad. In a preferred embodiment, the top, middle and bottom tubes are approximately the same length. Preferably, the armpit pad is gel-filled.
In a preferred embodiment, the middle tube comprises a top half and a bottom half; the middle tube comprises four series of spirally aligned apertures, two of which are located in the top half of the middle tube, and two of which are located in the bottom half of the middle tube; and the spirally aligned apertures are configured such that each aperture has a corresponding aperture exactly horizontal to it on an opposite side of the middle tube to facilitate securing the top and bottom tubes inside of the middle tube.
In a preferred embodiment, the hand grip comprises a cushioned pad and a metal bar; the middle tube comprises a middle; the metal bar is attached to the middle of the middle tube; the metal bar extends from the middle tube in one direction, makes a U turn, and then extends in an opposite direction to a point beyond the middle tube, thereby forming a short arm and a long arm of the metal bar; the cushioned pad is wrapped around the long arm of the metal bar; the cushioned pad comprises a center; the foot pad comprises a center; and the center of the cushioned pad is directly adjacent to the center of the foot pad from the perspective of a top view of the crutch. Preferably, the cushioned pad is gel-filled.
In a preferred embodiment, the present invention further comprises a rubber strap; the rubber strap is used to secure the top, middle and bottom tubes together when the crutch is disassembled; the rubber strap comprises a first end and a second end; the first end of the rubber strap is attached to the middle tube at a point directly beneath the point at which the metal bar of the hand grip is attached to the middle of the middle tube; there is a side of the middle tube that faces the patient when the crutch is in use and a side of the middle tube that does not face the patient when the crutch is in use; and the point at which the rubber strap is attached to the middle tube is on the side of the middle tube that faces the patient when the crutch is in use.
In a preferred embodiment, the present invention further comprises a clipboard, and the clipboard attaches to the middle tube at a point on the middle tube directly opposite the point at which the rubber strap attaches to the middle tube. Preferably, the clipboard comprises a magnetic strip.
In a preferred embodiment, the present invention further comprises a removable beverage holder; the beverage holder comprises a top end and a bottom end; the top end of the beverage holder attaches to the middle tube at a point on the middle tube directly opposite the point at which the rubber strap attaches to the middle tube; and the bottom end of the beverage holder is not attached to the middle tube so that it can swing freely and maintain a vertical orientation when the crutch is in use.
In a preferred embodiment, the crutch is used by a patient, and the shock absorber is adjustable based on the weight of the patient. Preferably, the footpad comprises a broad rounded underside that allows the foot pad to rock in all directions.
In a preferred embodiment, the armpit pad assembly further comprises a primary swivel part, a first washer, a cap, a second washer, a nut, and a shoulder bolt; the armpit pad comprises an underside; the primary swivel part is inserted into the underside of the armpit pad and secured with the shoulder bolt; the primary swivel part comprises a top section, a disc, a bottom extension, and a threaded portion; the shoulder bolt extends through an aperture in the top section of the primary swivel part; the cap comprises a top surface with an aperture and an underside; the first washer is positioned over the bottom extension of the primary swivel part and the bottom extension inserted into the aperture in the top surface of the cap; the second washer is inserted over the bottom extension of the primary swivel part underneath the aperture in the top surface of the cap; the nut is screwed onto the threaded portion of the primary swivel part to secure the primary swivel part on the cap; the cap is affixed to the top end of the top tube; and the disc of the primary swivel part lies flat against the first washer, the first washer lies flat against the top surface of the cap, and the second washer lies flat against the underside of the top surface of the cap, thereby allowing the armpit pad to swivel horizontally in relation to the top tube.
In a preferred embodiment, the disc of the primary swivel part comprises a bottom surface; the primary swivel part comprises a bottom extension that extends downward from the bottom surface of the disc and connects to the threaded portion of the primary swivel part; the bottom extension has a height; the first washer, top surface of the cap, and second washer each has a thickness; and the height of the bottom extension is slightly greater than the total thickness of the first washer, the top surface of the cap, and the second washer.
In a preferred embodiment, the underside of the armpit pad comprises two angled walls and two shoulders; the top section of the primary swivel part fits in between the two shoulders of the armpit pad; the shoulder bolt extends through an aperture on one side of the armpit pad, through one of the two shoulders, through the aperture in the top section of the primary swivel part, and through the other shoulder; and the shoulder bolt comprises a threaded portion that screws into a side wall of the armpit pad.
In a preferred embodiment, the angled walls of the armpit pad allow the armpit pad to tilt vertically when the armpit pad assembly is fully assembled; each angled wall has an angle, and the angle of one angled wall is equal to the angle of the other angled wall; the angle of the angled walls determines how far the armpit pad is capable of tilting vertically; and the angle of the angled walls can be adjusted during manufacture to allow for greater or lesser tilt of the armpit pad.
In an alternate embodiment, the present invention is an ergonomic crutch comprising an armpit pad assembly; a top tube; a middle tube; a bottom tube; a hand grip; and a footpad assembly; the armpit pad assembly comprises an armpit pad and means for allowing the armpit pad to tilt vertically and swivel horizontally; the top tube comprises a top end and a bottom end, and the armpit pad assembly connects to the top end of the top tube; the middle tube comprises a top end and a bottom end; the bottom end of the top tube slides into the top end of the middle tube; the bottom tube comprises a top end and a bottom end; the top end of the bottom tube slides into the bottom end of the middle tube; and the hand grip is offset laterally from the middle tube. Preferably, the armpit pad is gel-filled.
In a preferred embodiment, the middle tube comprises a top half and a bottom half; the middle tube comprises four series of spirally aligned apertures, two of which are located in the top half of the middle tube, and two of which are located in the bottom half of the middle tube; and the spirally aligned apertures are configured such that each aperture has a corresponding aperture exactly horizontal to it on an opposite side of the middle tube to facilitate securing the top and bottom tubes inside of the middle tube.
In a preferred embodiment, the hand grip comprises a cushioned pad and a metal bar; the middle tube comprises a middle; the metal bar is attached to the middle of the middle tube; the metal bar extends from the middle tube in one direction, makes a U turn, and then extends in an opposite direction to a point beyond the middle tube, thereby forming a short arm and a long arm of the metal bar; the cushioned pad is wrapped around the long arm of the metal bar; the cushioned pad comprises a center; the foot pad comprises a center; and the center of the cushioned pad is directly adjacent to the center of the foot pad from the perspective of a top view of the crutch. Preferably, the cushioned pad is gel-filled.
In a preferred embodiment, the present invention further comprises a rubber strap; the rubber strap is used to secure the top, middle and bottom tubes together when the crutch is disassembled; the rubber strap comprises a first end and a second end; the first end of the rubber strap is attached to the middle tube at a point directly beneath the point at which the metal bar of the hand grip is attached to the middle of the middle tube; there is a side of the middle tube that faces the patient when the crutch is in use and a side of the middle tube that does not face the patient when the crutch is in use; and the point at which the rubber strap is attached to the middle tube is on the side of the middle tube that faces the patient when the crutch is in use.
In a preferred embodiment, the present invention further comprises a clipboard, and the clipboard attaches to the middle tube at a point on the middle tube directly opposite the point at which the rubber strap attaches to the middle tube. Preferably, the clipboard comprises a magnetic strip.
In a preferred embodiment, the present invention further comprises a removable beverage holder; the beverage holder comprises a top end and a bottom end; the top end of the beverage holder attaches to the middle tube at a point on the middle tube directly opposite the point at which the rubber strap attaches to the middle tube; and the bottom end of the beverage holder is not attached to the middle tube so that it can swing freely and maintain a vertical orientation when the crutch is in use.
Preferably, the footpad comprises a broad rounded underside that allows the foot pad to rock in all directions.
In a preferred embodiment, the armpit pad assembly further comprises a primary swivel part, a first washer, a cap, a second washer, a nut, and a shoulder bolt; the armpit pad comprises an underside; the primary swivel part is inserted into the underside of the armpit pad and secured with the shoulder bolt; the primary swivel part comprises a top section, a disc, a bottom extension, and a threaded portion; the shoulder bolt extends through an aperture in the top section of the primary swivel part; the cap comprises a top surface with an aperture and an underside; the first washer is positioned over the bottom extension of the primary swivel part and the bottom extension inserted into the aperture in the top surface of the cap; the second washer is inserted over the bottom extension of the primary swivel part underneath the aperture in the top surface of the cap; the nut is screwed onto the threaded portion of the primary swivel part to secure the primary swivel part on the cap; the cap is affixed to the top end of the top tube; and the disc of the primary swivel part lies flat against the first washer, the first washer lies flat against the top surface of the cap, and the second washer lies flat against the underside of the top surface of the cap, thereby allowing the armpit pad to swivel horizontally in relation to the top tube.
In a preferred embodiment, the disc of the primary swivel part comprises a bottom surface; the primary swivel part comprises a bottom extension that extends downward from the bottom surface of the disc and connects to the threaded portion of the primary swivel part; the bottom extension has a height; the first washer, top surface of the cap, and second washer each has a thickness; and the height of the bottom extension is slightly greater than the total thickness of the first washer, the top surface of the cap, and the second washer.
In a preferred embodiment, the underside of the armpit pad comprises two angled walls and two shoulders; the top section of the primary swivel part fits in between the two shoulders of the armpit pad; the shoulder bolt extends through an aperture on one side of the armpit pad, through one of the two shoulders, through the aperture in the top section of the primary swivel part, and through the other shoulder; and the shoulder bolt comprises a threaded portion that screws into a side wall of the armpit pad.
In a preferred embodiment, the angled walls of the armpit pad allow the armpit pad to tilt vertically when the armpit pad assembly is fully assembled; each angled wall has an angle, and the angle of one angled wall is equal to the angle of the other angled wall; the angle of the angled walls determines how far the armpit pad is capable of tilting vertically; and the angle of the angled walls can be adjusted during manufacture to allow for greater or lesser tilt of the armpit pad.
1 Armpit pad
2 Top tube
3 Middle tube
4 Bottom tube
5 Hand grip
6 Footpad
7 Shock absorber
8 Cushioned pad
9 Metal tube (of hand grip)
10 Spirally aligned apertures (on middle tube)
11 Spring pin
12 Adjustment knob (on shock absorber)
13 Piston (of shock absorber)
14 Barrel (of shock absorber)
15 Rubber strap
16 Clipboard
17 Beverage holder
18 Armpit pad assembly
19 Nut
20 Bolt
21 Foot pad assembly
22 Knob (on spring pin)
23 Aperture (on top tube)
24 Knob (on rubber strap)
25 Apertures (in rubber strap)
26 Primary swivel part
27 First washer
28 Cap
29 Second washer
30 Nut
31 Shoulder bolt
32 Aperture (in top section of primary swivel part)
33 Threaded portion (of primary swivel part)
34 Aperture (in cap)
35 Disc (of primary swivel part)
36 Angled wall (of armpit pad)
37 Shoulder (of armpit pad)
38 Top section (of primary swivel part)
39 Threaded portion (of shoulder bolt)
40 Nut
41 Bolt
42 Extension (on barrel of shock absorber)
43 Aperture (in bottom tube)
44 Threaded recess (in foot pad)
45 End piece
46 Magnetic strip
47 Threaded extension (of end piece)
48 Aperture (in armpit pad)
49 Bottom extension (of primary swivel part)
The hand grip 5 is welded onto the middle tube 3 and preferably comprises a gel-filled cushioned pad 8 for ease of grip. The present invention is not limited to any particular type of cushioned pad; the cushioned pad could be made of rubber or foam, for example. The hand grip 5 further comprises a metal bar 9 that extends in one direction from the middle tube 3, makes a U turn, and then extends in an opposite direction to a point beyond the middle tube 3 (this is also shown more clearly in
The middle tube 3 preferably comprises four series of spirally aligned apertures 10, two situated underneath the hand grip 5 on the middle tube 3 and two situated above the hand grip 5 on the middle tube 3. These apertures 10 are aligned spirally to avoid the weakness in the middle tube 3 that would result if they were vertically aligned, and also to provide greater flexibility in terms of positioning the top and bottom tubes 2, 4 inside of the middle tube 3 (see
The shock absorber 7 absorbs some of the weight of the patient and allows the patient to maintain a horizontal plane at the level of the armpit pad 1 when using the crutch as compared to the arc-shaped path of travel of the armpit pad 1 on a crutch without a shock absorber 7. Combined with the vertically tilting armpit pad 1, the shock absorber 7 allows the armpit pad 1 to stay horizontal and in contact with the patient's armpit throughout the walking cycle. This results in a forward motion that is more fluid, level, and comfortable for the patient. It also allows the patient to rely more heavily on the armpit pad to carry her weight as opposed to the patient having to carry all of her weight with her arms.
The shock absorber 7 is designed to fit into the inner diameter of the bottom tube 4 and is fastened to the bottom tube 4 with a nut and bolt (see
In a preferred embodiment, the piston 13 of the shock absorber 7 extends below the bottom tube 4 and has a stroke of approximately three inches. The diameter of the barrel 14 of the shock absorber 7 is slightly less than the inside diameter of the bottom tube 4.
As shown in
The crutch shown in
As this figure illustrates, the top, middle and bottom tubes 2, 3, 4 are preferably approximately the same length. The outside diameter of the top and bottom tubes 2, 4 is slightly less than the inside diameter of the middle tube 3 so that the top and bottom tubes can slide into the middle tube for assembly of the crutch and out of the middle tube for disassembly and storage or transport.
In a preferred embodiment, each spirally aligned series of apertures 10 (there are two on the top half of the middle tube 3 and two on the bottom half of the middle tube 3) is labeled either with numbers or letters (shown with letters in
The primary swivel part 26 comprises a disc 35 that lies flat up against the first washer 27 when the armpit pad assembly 18 is assembled. The nut 30 is screwed tightly enough to hold the assembly in place but not so tight as to preclude the disc 35 from rotating on the first washer 27. Because the threaded portion 33 of the primary swivel part 26 is fixedly connected to the nut 30, the nut 30 rotates on the second washer 29 at the same time and to the same degree that the disc 35 of the primary swivel part 26 rotates on the first washer 27. The cap 28 is stationary during rotation of the primary swivel part 26 because it is fixedly attached (but not necessarily welded) to the top end of the top tube 2.
Because of the primary swivel part 26 and the manner in which it is attached to the cap 28 and then armpit pad 1, the armpit pad 1 can swivel horizontally to accommodate the most comfortable position for the patient using the crutch. In particular, the horizontal swivel allows a patient to achieve the best angle of the hand grip 5 in relation to the armpit pad 1 for maximum comfort. This principle is illustrated in
The angled walls 36 of the armpit pad 1 allow the armpit pad to tilt vertically when the armpit pad assembly 18 is fully assembled (see
In addition to affording the advantageous features described above, namely, the horizontally swiveling and vertically tilting armpit pad, the offset hand grip, the gas shock, the optimally shaped foot pad, and the three-part tubing, the present invention is also designed to accommodate accessories, such as clipboards and beverage holders, to make it even more convenient for the patient on crutches to function.
Although the preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention.