WO2010085668A2

WO2010085668A2 - Sport swing training device and methods therefor

Info

Publication number: WO2010085668A2
Application number: PCT/US2010/021837
Authority: WO
Inventors: Michael Bard; Brad Andress
Original assignee: LEAD DAWG SPORTS LLC
Current assignee: LEAD DAWG SPORTS LLC
Priority date: 2009-01-23
Filing date: 2010-01-22
Publication date: 2010-07-29
Anticipated expiration: 2011-07-23
Also published as: WO2010085668A3

Abstract

A sport swing training device including a resistance mechanism and first and second leg receivers adapted to confront a user's inner legs. The resistance mechanism is movable between an expanded state and a compressed state. The resistance mechanism is operative to resist movement from the expanded state to the compressed state. The first and second leg receivers are disposed on opposite ends of the resistance mechanism. Preferably, the leg receivers have an arcuate configuration and include at least one strap for securing the resistance mechanism to the user's legs. Preferably, the training device also includes a feedback indicator operative to indicate when the resistance mechanism has been moved to the compressed state, which in practice corresponds to the point at which the user strikes a projectile. In an exemplary embodiment, the feedback indicator comprises an audible device, such as a whistle, operated by pneumatic pressure created within the dashpot.

Description

SPORT SWING TRAINING DEVICE AND METHODS THEREFOR

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of United States Provisional Application No. 61/147,054, filed January 23, 2009, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

Many people have seen the classic figure skater's spin where the skater draws in her arms resulting in the speed of her spin increasing significantly. This effect is a result of the law of conservation of angular momentum (L). As the skater pulls in her arms she reduces her rotational inertia (I). In order to conserve angular momentum her rotational speed, or angular velocity, (ω) must increase in proportion to the amount she reduces her rotational inertia.

L = I ω

Note that rotational inertia increases as the square of the distance (r) from the axis of rotation. Doubling the distance of a mass (m) from its axis of rotation quadruples the rotational inertia associated with the mass.

I = mr

Thus, even a minor change in arm and/or leg position can have a significant effect on rotational inertia resulting in a corresponding increase or decrease in angular velocity.

It is less commonly known that the law of conservation of angular momentum can be applied to improve an athlete's performance in swinging a bat, club, or racquet. For example, as a baseball player swings a bat, if he can reduce his rotational inertia just before or at the point of impacting the ball, he maximizes his bat speed; thus, resulting in better horizontal drive and rotational velocity. In baseball this is referred to as "staying tight," which in part refers to bringing the knees together (leg compression) to reduce the batter's rotational inertia.

This concept is much easier to explain than it is to put into actual practice. A batter's swing is all about timing and coordination. To develop a consistently good swing requires skill, natural ability, and most important, practice. However, that practice must be correctly performed; otherwise, incorrect practice can do more harm than good. Thus there is a need for a device to aid players and trainers in practicing and teaching proper swing techniques, such as the optimum amount of leg compression and leg compression timing.

SUMMARY

Provided herein is a sport swing training device including a resistance mechanism and first and second leg receivers adapted to confront a user's inner legs. The resistance mechanism is movable between an expanded or extended state and a compressed or collapsed state. Generally the resistance mechanism is operative to dampen movement of the user's legs. More specifically, the resistance mechanism is operative to resist movement from the expanded state to the compressed state, while being easily expanded. The first and second leg receivers are disposed on opposite ends of the resistance mechanism. Preferably, the leg receivers have an arcuate configuration. The leg receivers may also include at least one strap for securing the resistance mechanism to the user's legs.

In an exemplary embodiment the resistance mechanism comprises a pneumatic dashpot. The dashpot comprises a cylinder sized and configured to slidably receive a plunger. The plunger includes a one-way air valve operative to allow air to flow through the plunger when the dashpot is moved from the collapsed state to the extended state and restrict air flow through the plunger when the dashpot is moved from the extended state to the collapsed state. The dashpot may include an adjustable valve operative to vary the amount of resistance provided by the dashpot. Alternatively or in combination the resistance mechanism may include a compression spring.

Preferably, the training device also includes a feedback indicator operative to indicate when the resistance mechanism has been moved to the compressed state, which in practice corresponds to the point at which the user strikes a projectile. In an exemplary embodiment, the feedback indicator comprises an audible device operated by pneumatic pressure created within the dashpot. In particular, the audible device may comprise a whistle. In an alternative embodiment the feedback indicator is an electronic enunciator.

Various sensors could be included with the training device for recording performance parameters. For example, a pressure sensor and/or displacement sensor may be included on the device and connected to a display and recording device.

Also contemplated are methods for training a user to swing at a projectile, such as a baseball or golf ball, using the leg compression technique described herein. In an exemplary embodiment, the method includes providing resistance to inward movement of the user's knees; instructing the user to swing at the projectile while moving his legs together; providing a feedback signal when the user's legs have moved together a selected amount; and instructing the user to contact the projectile at the same time the user perceives the feedback signal. Preferably, the user is instructed to swing at the projectile while moving his rear leg toward his front leg, which is preferably planted. The feedback signal may be accomplished with an audible signal, for example.

The methods may include recording a user's performance parameters and comparing them over time. For example, the method may include recording how far a user's legs move together over an interval of time. Also, where the resistance to inward movement of the user's knees is provided by a dashpot, the pressure developed in the resistance device may be recorded and compared with data from prior training sessions.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate multiple embodiments of a sport swing training device and together with the description, serve to explain the principles thereof. Like items in the drawings are referred to using the same numerical reference.

FIG. 1 is a perspective view of a baseball player illustrating the use of a sports swing training device according to a first exemplary embodiment;

FIG. 2 is a perspective view of the training device shown in FIG. 1 in an extended state;

FIG. 3 is a perspective view of the training device shown in FIGS. 1 and 2 in a compressed state;

FIG. 4 is a perspective view of a sports swing training device according to a second exemplary embodiment;

FIG. 5 is a perspective view of a sports swing training device according to a third exemplary embodiment; and

FIG. 6 is a perspective view of a baseball player illustrating the use of a sports swing training device according to a fourth exemplary embodiment.

DETAILED DESCRIPTION

The sport swing training device described herein provides positive audible and motion resistive biofeedback to reinforce properly executed leg compression techniques during a swing. The disclosed training device is a convenient and easy to use device that while providing feedback for specific movements, otherwise allows players freedom of movement. Thus, players are free to perform their swing according to their own style and biomechanics yet still benefit from feedback specific to the leg compression technique. The technology of the present application will be explained with reference to the figures and exemplary embodiments. While the technology is explained with particular reference to certain devices and materials, it should be understood that those devices and materials are exemplary in nature and should not be construed as limiting.

FIG. 1 illustrates a baseball player practicing his swing with the aid of training device 10. Training device 10 is worn between the player's right and left legs (5 and 7). Ideally, the device is situated just above the knees, but may be placed anywhere along the thigh, knee, or calf. As player 2 swings bat 3 he moves his legs (5 and 7) closer together as he rotates to strike a ball. Preferably, the player moves his trailing leg 5 towards his forward leg 7, which remains planted. While his legs move together, training device 10 provides resistance to assist the player in developing the proper timing of the leg compression technique. Also, audible feedback is provided at the point of maximum leg compression, which should occur at approximately the same time the player contacts the ball. It should be appreciated that other forms of feedback, such as tactile or visual feedback are also contemplated. Furthermore, while the use of training device 10 is illustrated here with respect to a baseball player, it should be understood that this training device may be used for practicing other sports such as golf, hockey, boxing, and racquet sports such as tennis and racquetball, to name a few.

Training device 10 includes resistance mechanism 20 and first and second leg receivers 30 and 40. Training device 10 is movable between an expanded state (see FIG. 2) and a compressed state (see FIG. 3). Referring to FIG. 3, it can be appreciated that leg receivers 30 and 40 may also rotate and pivot relative to each other. Leg receivers 30 and 40 each include an arcuate yoke 32 and 42 respectively, which define leg regions 34 and 44. Attached to the ends of each yoke are straps 35(l)/35(2) and 45(l)/45(2). The straps include cooperative fasteners 37/38 and 47/48. Accordingly, the user's legs may each be strapped into a corresponding leg region and secured therein with the cooperative fasteners. Straps 35 and 45 may be any suitable material such as nylon webbing, for instance. Cooperative fasteners 37/38 and 47/48 could be a knot tied between the two ends of the straps, cooperative hook and loop materials, a buckle, or as shown in the figures, a male/female style buckle.

In this embodiment, resistance mechanism 20 is in the form of a shock absorber or dashpot, which provides pneumatic, or fluid, resistance when leg receivers 30 and 40 are moved together toward the compressed state. Resistance mechanism 20 is one non-limiting example of a means to determine when the user's legs are compressed sufficiently close to one another. It is envisioned the dashpot or shock absorber would use air to resist movement, but other gases or liquids are possible. Resistance mechanism 20 includes cylinder 22, which has a closed end 24 and an open end 26. Open end 26 is sized and configured to slidably receive plunger 28. Plunger rod 43 is attached to plunger 28 and extends through cylinder cap 46. Cylinder cap 46 is secured to open end 26 of cylinder 22, thereby retaining plunger 28 in cylinder 22. First leg receiver 30 is disposed on the closed end 24 of cylinder 22. Second leg receiver 40 is disposed on plunger rod 43, opposite plunger 28. Thus, relative motion between leg receivers 30 and 40 acts to translate plunger 28 along cylinder 22. Cylinder cap 46 may be secured to cylinder 22 by a press fit, mating threads, or the like. It should also be noted that the cylinder is represented in the figures as being transparent in order to show the internal components of the resistance mechanisms. However, the cylinder may be formed of any suitable material transparent or otherwise. For example, the cylinder may be formed of plastic such as Lexan, Plexiglas, or polyvinylchloride (PVC), to name a few or metals such as aluminum or steel, for instance.

Plunger 28 includes seal 27, such as an O-ring, and a one-way air valve 21. Seal 27 is operative to seal plunger 28 against the interior of cylinder 22. One-way air valve 21 is operative to only allow air to flow through plunger 28 from the rod side of the plunger. Thus, plunger 28 may move freely toward an expanded state yet its movement is resisted by air pressure when moved toward a compressed state. As training device 10 is compressed, air trapped in cylinder 22 between closed end 24 and plunger 28 increases in pressure and thus provides resistive feedback to the player. On the other hand it can be appreciated that as training device 10 is expanded, air on the rod side of plunger 28 is allowed to freely flow through the plunger thus exerting little resistance to the expansion of training device 10. Cylinder cap 46 may also include a vent 49 to further facilitate the flow of air during expansion.

As the air pressure in cylinder 22 increases, air is forced through whistle 23. Whistle 23 is in fluid communication with the interior of cylinder 22. The amount of resistive feedback and corresponding rate of compression is determined by the size of the effective orifice 25 in whistle 23. A smaller effective orifice increases the resistive feedback while a larger effective orifice would decrease the resistive feedback. Optional adjustment valve 29 may also be included. Adjustment valve 29 can be adjusted to vary the amount of resistive feedback and the point at which whistle 23 reaches a threshold pressure where audible feedback is perceptible to the player. Adjustment valve 29 may be any suitable valve with an adjustable orifice, such as a needle valve. Alternatively, whistle 23 and adjustment valve 29 may be combined into a single release valve that provides an audible indication when pressure exceeds a threshold pressure, similar to a pop-off or a release valve. FIG. 4 illustrates a training device 110 according to a second exemplary embodiment. Training device 110 is similar to the first exemplary embodiment described above with respect to FIGS. 2 and 3, except that resistance mechanism 120 comprises a compression spring 127. Plunger rod 143 is connected to plunger 128, which compresses spring 127 when training device 110 is compressed, thereby providing resistive feedback. Plunger 128 includes ports 121 ' and 121 ", which allow air to freely flow, in both directions, across plunger 128 preventing any restriction due to air compression. Accordingly, it is not necessary for plunger 128 to include a seal in this case. An audible feedback device 150 is disposed proximate the closed end 124 of cylinder 122. Audible feedback device 150 could include a sensor for detecting the presence of plunger 128, such as a proximity sensor or a mechanical switch. The feedback signal could be activated at a threshold position or could be a continuous tone that is varied in pitch as the resistance mechanism is compressed. Alternatively, a strain gage or load cell could be used to detect the amount of compression being applied to the spring. Audible feedback device 150 could include appropriate circuitry and power source, as is known in the art, to activate an enunciator such as a piezoelectric buzzer based on the location of the plunger or the amount of compression applied to the spring.

FIG. 5 illustrates training device 210 according to a third exemplary embodiment, which is the same as the first exemplary embodiment with the addition of instrumentation. Training device 210 is instrumented with a pressure sensor 250 and a displacement sensor 252. Displacement sensor 252 may be a linear variable differential transducer (LVDT), which is mounted to cylinder 222 with brackets 251 ' and 251 ". Sensor core 253 may be attached to plunger rod 243 with a suitable bracket 254. Accordingly, as training device 210 is compressed, sensor core 253 moves with plunger rod 243, thereby recording any relative movement of leg receivers 230 and 240. Displacement sensor 252 and pressure sensor 250 may be connected via cable 255 to a suitable display and/or recording device 257, such as an oscilloscope. In this embodiment not only does the player receive immediate feedback but the sensor information may be recorded for later analysis.

FIG. 6 illustrates a fourth exemplary embodiment of a sport swing training device. Swing training device 310 comprises a proximity sensor portion 340 and an emitter portion 330. Sensor portion 340 and emitter portion 330 are another non-limiting example of a means to determine when the user's legs are compressed sufficiently close to one another. In this case emitter portion 330 includes a magnet 335. Proximity sensor portion 340 includes a proximity sensor 345, such as a Hall Effect sensor or other magnetic pick-up, capable of detecting the magnetic field emitted from magnet 335 or other device on emitter portion 330. Sensing portion 340 includes an enunciator 347, such as a speaker, buzzer, or the like that may provide an audible or tactile feedback. As sensor portion 340 is moved closer to emitter portion 330 the frequency of the audible output generated by enunciator 347 varies in relation to the strength of the signal detected by the sensor 345, which in turn varies by the proximity of the emitter 330. As shown in FIG. 6, this embodiment may or may not include a resistance mechanism in conjunction with the feedback indicator. Preferably, the sensor portion and emitter portion are strapped to the user's legs proximate the knee such that the sensor and emitter portions face each other. Swing training device 310 may estimate or simulate resistance using the speed that the sensors are approaching either other, which may be detected using a rate of change of signal strength or the like.

Methods relating to the above described sport swing training device are also contemplated. The methods thus encompass the steps inherent in the above described mechanical structures. Broadly, one method could include the step of applying resistance to a user's inner legs as the user compresses his knees together during a sport swing. The method could include the step of providing audible feedback at the point where the user has properly compressed his legs together. Another method could also include the step of recording and/or displaying information relating to force, time, pressure, and/or displacement.

Accordingly, the sport swing training device has been described with some degree of particularity directed to the exemplary embodiments. It should be appreciated, though, that the contemplated device is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the exemplary embodiments without departing from the inventive concepts contained herein.

Claims

I claim:

1. A sport swing training device, comprising: a resistance mechanism movable between an expanded state and a compressed state, said resistance mechanism operative to resist movement from the expanded state to the compressed state; first and second leg receivers disposed on opposite ends of said resistance mechanism and adapted to confront a user's legs; and a feedback indicator operative to indicate when the resistance mechanism has been moved to the compressed state.

2. A training device according to claim 1, wherein said resistance mechanism comprises a pneumatic dashpot.

3. A training device according to claim 2, wherein said dashpot includes an adjustable valve operative to vary the amount of resistance provided by said dashpot.

4. A training device according to claim 2, wherein said feedback indicator comprises an audible device operated by pneumatic pressure created within said dashpot.

5. A training device according to claim 4, wherein said audible device comprises a whistle.

6. A training device according to claim 1, wherein said resistance mechanism comprises a compression spring.

7. A training device according to claim 1, wherein said feedback indicator is an electronic enunciator.

8. A sport swing training device, comprising: a dashpot movable between an extended state and a collapsed state; and first and second arcuate leg receivers disposed on opposite ends of said dashpot and securable to a user's legs, whereby movement of the user's legs is dampened by said dashpot.

9. A training device according to claim 8, including a feedback indicator operative to indicate when the dashpot has been moved to the collapsed state.

10. A training device according to claim 9, wherein said feedback indicator is a pneumatically operated device.

11. A training device according to claim 10, wherein said feedback indicator is an audible device.

12. A training device according to claim 8, wherein said first and second leg receivers each include a strap for securing said receivers to the user's legs.

13. A training device according to claim 8, wherein said dashpot comprises a cylinder sized and configured to slidably receive a plunger, said plunger including a one-way air valve operative to allow air to flow through the plunger when said dashpot is moved from the collapsed state to the extended state and restrict air flow through the plunger when said dashpot is moved from the extended state to the collapsed state.

14. A training device according to claim 8, including a pressure sensor connectable to a recording device.

15. A training device according to claim 8, including a displacement sensor connectable to a recording device.

16. A method of training a user to swing at a projectile with leg compression, the method comprising: providing resistance to inward movement of the user's legs; instructing the user to swing at the projectile while moving legs together; providing a feedback signal when the user's legs have moved together a selected amount; and instructing the user to contact the projectile at the same time the user perceives the feedback signal.

17. The method according to claim 16, including recording how far the user's legs move together over an interval of time.

18. The method according to claim 16, wherein the step of providing a feedback signal is accomplished with an audible signal.

19. The method according to claim 16, instructing the user to swing at the projectile while moving rear leg toward front leg.

20. A sport swing training device, comprising: means for sensing a proximate distance between a user's legs as part of a sport swing; means for coupling the means for sensing to the user's legs; and means for providing feedback to the user when the user's legs have moved sufficiently close together.