Patent Application
20120322632
1. Field of the Invention
The invention pertains to exercise equipment and methods of using the same. More particularly the invention relates to a flexible pole for upper body exercises, particularly when walking.
2. Description of Related Art
It is known in the art of exercise physiology that one can greatly increase the effectiveness of walking by doing various movements to involve the muscles of the upper body. This can be done by the use of wrist weights, for example, or by carrying various poles, sticks, and the like. In some cases, hiking sticks or poles are modeled after ski poles and this practice is commonly referred to as Nordic walking. The poles are generally substantially rigid and are used by grasping the upper end and pushing the lower end backwards against the ground, thereby propelling the user forward and exercising the arm muscles.
Some typical walking poles are disclosed by: Helm in U.S. Pat. Appl. Pub. 2009/0314320; Stephens et al. in U.S. Pat. Appl. Pub. 2008/0121260; and Dale in U.S. Pat. No. 4,958,650.
Ski poles are made of various materials, such as aluminum and composite materials, as taught by Goode in U.S. Pat. No. 5,024,866. As Goode makes clear, a ski pole must be strong enough to adequately support the body weight of a skier, and must withstand significant bending loads without bending too much.
Reilly, in U.S. Pat. Appl. Pub. 2010/0179037, discloses an exercise pole intended to be used primarily for stretching exercises. The pole is substantially rigid along most of its length and has a partially flexible handle, intended to relieve stress on the hands and the wrists of the user.
Wright, in U.S. Pat. No. 5,739,139 discloses a set of lunge poles, which are rotatably mounted in a base. The poles are substantially rigid and serve to help the user maintain his or her balance while performing lunging exercises. The poles may be joined together by a resilient band in order to increase the resistance to relative movement in order to increase the intensity of the workout.
The aforementioned devices suffer from various shortcomings that limit their usefulness in several exercise regimes. First, conventional Nordic walking poles don't provide adequate involvement of the abdominal muscles, because the user is simply pushing backwards against the ground. Second, all of the poles are substantially rigid and therefore don't provide an element of resistance over a wide range of motions. Third, they tend to be limited to either walking or stationary exercises and are not adapted to both.
Objects of the present invention include the following: providing an exercise pole that can be used in both walking and stationary exercise activities; providing a flexible exercise pole that may be elastically deformed over a wide range to provide resistance over a range of muscle movement; providing a walking pole that allows the user to apply a controlled bending moment that is resisted by the user's abdominal muscles; providing an exercise pole that may be used in both walking and stationary settings; providing an exercise pole that may be used in both indoor and outdoor activities; and providing a method of exercise in which walking poles are flexibly bent and unbent to provide additional muscle involvement for the user. These and other objects and advantages of the invention will become apparent from consideration of the following specification, read in conjunction with the drawings.
According to one aspect of the invention, an exercise pole comprises:
a flexible shaft capable of repetitive elastic flexure of at least 2% of its length in response to a bending load;
a hand grip on the upper end of the shaft to allow a user to apply the bending load; and,
a ground-engaging tip on the lower end of the shaft to engage a selected working surface.
According to another aspect of the invention, a method of exercise comprises the steps of:
grasping a flexible shaft, using a hand grip at the upper end of the shaft, the shaft further having a ground-engaging tip at its lower end;
placing the tip on a working surface;
applying a bending moment through the hand grip sufficient to deflect the flexible shaft at its midsection by at least about 2% of its length;
reducing the bending moment so that the flexible shaft returns controllably to a straight position before lifting the tip from the surface.
The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer conception of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting embodiments illustrated in the drawing figures, wherein like numerals (if they occur in more than one view) designate the same elements. The features in the drawings are not necessarily drawn to scale.
In its most general form,
Conventional ski poles and Nordic walking sticks are substantially rigid bodies. They may exhibit a small degree of flex or compliance, but they are not intended to be repetitively flexed by the user in order to work various muscle groups. A Nordic walking stick is used by engaging the lower tip on the ground and pushing backwards, thereby propelling the body forward, in the same way that one would use the poles in Nordic or cross-country skiing. From a kinematic viewpoint, the arms are simply providing some of the work needed to move the user forward, rather than all of the work being provided by the leg muscles. Because conventional poles have no significant degree of elastic flexure, they can't provide the user with a resistive workout over a large rotational movement.
By contrast, the inventive poles are extremely flexible. The user engages the lower tip on the ground and applies a bending moment with the wrist. As shown in
The stick 10 shown in
One material that Applicant has found to be suitable for the stick is a solid polymeric (fiberglass reinforced) shaft about 9 mm diameter (Vinylester Rod ⅜″ diameter, black, Glasforms, Inc., Birmingham, Ala. 35217). With this material, a stick about 1.3 m long can easily be flexed by about 10 cm (measured as the deflection of the center of the stick from the line joining the two ends). Selected specifications for this material are: Glass Content, 75 wt. %; Tensile Strength, 120,000 psi; Tensile Modulus, 6×108 psi; Flexural Strength, 120,000 psi; Flexural Modulus, 6×106 psi; Compressive Strength, 6,000 psi; Barcol Hardness, 60 (ASTM D2583).
Applicant has found that this material is quite resilient and has shown no signs of fatigue or other incipient mechanical failure after repeated flexure.
It will be appreciated that other familiar materials such as wood, metal alloys, polymers and polymer composites may also be used, provided their diameter and length are matched so that adequate flexure can be induced with appropriate force by the user, and the stick will at all times deform in the elastic (rather than plastic) regime.
The stick in the preceding example was fitted with a compliant tip 11 on the end that is intended to engage the ground or other surface. One suitable tip is a standard rubber product (Chair, Cane, and Crutch Tips, black, ⅜ inch ID, McMaster-Carr, Atlanta, Ga. 30036). Other suitable materials may be used, which preferably meet the following criteria: 1. The diameter of the tip is larger than the diameter of the stick so it may be slipped onto the stick; and 2. The tip material is appropriate for the intended working surface.
For outdoor use, the tip may be fitted with a relatively hard point, whereas for indoor use the tip is preferably softer than the stick material, as was used in the preceding example. These qualities allow the tip to engage an irregular working surface securely, and also help to prevent damage to surfaces when used indoors, or damage to the stick when used on pavement or rocky terrain as will be explained in later examples. The hard point intended for outdoor use may be of any suitable material including hardened steel, metal carbides, ceramics, diamond, and hardmetal composites such as cobalt-bonded tungsten carbide.
It will be apparent that a stick of a suitable diameter to allow sufficient flexure will generally be too small to grip comfortably, so in most cases it will be preferred to have a hand grip 12 on the upper end of the stick. Hand grip 12 may be of the type conventionally used on ski poles, and may be mounted on a substantially straight stick. Alternatively, the end of the stick may be bent at an angle to provide a more natural grip. As shown in
The stick of the preceding example was fitted with a hand grip 12 as follows: A length of PVC tubing (˜22 mm o.d.) was heated and bent about 40° in the middle. Stick 10 was adhesively bonded to the inside of the bent PVC tube. A compliant tool grip (Soffoam Grips, Sinclair and Rush, Inc., Arnold, Mo. 63010) was then slipped over the PVC tube to provide a comfortable and slightly compliant gripping surface.
It will be appreciated that many other means of creating a compliant grip may be used. For example, layers of tape such as that used on bicycle handlebars may be used, as well as other grips such as hand grips used on bicycles, motorcyles, wheelbarrows, and the like. The hand grip may include indentations to accommodate the user's fingers, and a retaining strap or handsling as are often used in ski poles. It will be further appreciated that the invention is not limited to a particular angle of bend in the gripping region.
A series of tests were conducted to quantify the flexure of various materials, as shown in the following table. The stick material was supported at two ends and various weights were applied at the center of the span. Downward deflection was measured at that point. Tests used a fairly rigid aluminum pole material (“Swissgear-Anti-shock” three-piece adjustable height aluminum pole) with a span of 108 cm, and two polymer stick materials, (1) a diameter of 0.92 cm (0.312 in.) and a span of 109 cm; and (2) a diameter of 0.95 cm (0.375 in.) and a span of 127 cm.
One can see that the polymer sticks provide a significantly greater degree of flex, up to ˜17%, for a given load than does the aluminum stick, which deflects up to ˜2.5% under the maximum load applied in this test. It will be appreciated that the properties and dimensions of the stick may be adjusted to meet the needs of a particular user; for instance, one use might prefer a more vigorous workout and therefore will want a pole that requires more load to deflect by the desired amount of bend, whereas, another user might prefer a pole that requires less load to make it deflect by the desired amount of bend. A weaker or more flexible shaft might be indicated, for example, for elderly users or those undergoing various rehabilitative activities. In general, Applicant prefers that the pole will deflect elastically by at least 2%, and more preferably by at least 4% as defined by the deflection from the centerline at the midpoint of the stick.
Referring to
The invention may also be used indoors in various ways. The user can simply plant the tips in any convenient place on the interior surface of the room, such as at the intersection of wall and floor, and flex them in various ways to provide an upper body workout or for limbering up after spending time seated at a workstation, for instance.
Alternatively, somewhat shorter sticks (˜75 cm) may be used by elderly users who might be confined to a wheelchair, or might simply wish to remain seated for better balance.
