US20090243238A1

US20090243238A1 - Skate boot

Info

Publication number: US20090243238A1
Application number: US12/249,741
Authority: US
Inventors: Scott Van Horne; David CRUIKSHANK
Original assignee: Dasc LLC
Current assignee: Bauer Hockey LLC
Priority date: 2007-10-10
Filing date: 2008-10-10
Publication date: 2009-10-01
Also published as: WO2009049244A1

Abstract

A skate boot includes a foot portion configured to receive and secure a foot of a wearer. The skate boot includes a first tendon guard positioned proximal an Achilles tendon of a wearer of the skate boot, the first tendon guard being connected to the foot portion at a first articulation point and adjacent the foot portion along a medial abutment line and a lateral abutment line. The skate boot may optionally include a second tendon guard connected to the foot portion at a second articulation point and to the first tendon guard, the second tendon guard covering the first articulation point. In at least one embodiment, an elastomeric band is connected to the foot portion and to the first tendon guard and configured to bias the first tendon guard to a closed position. In at least one embodiment, an electrical generator is provided to heat an ice skate interconnected to the boot.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Patent Application No. 60/978,758 filed on Oct. 10, 2007, entitled “Skate Boot,” the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.

FIELD

The present invention relates generally to ice skates and more specifically to the construction of the rigid support component of the skate boot, traditionally referred to as the sole and counter of the boot.

BACKGROUND

Skating locomotion is based on propulsion through a glide technique. The skate blade that is performing the push glides at a right angle to the direction of the push force (Boer et al., 1986; Boer et al., 1989; van Ingen Schenua et al., 1980; van Ingen Schenua et al., 1985, van Ingen Schenua at al., 1987). This causes the trajectory of the body to look like a sine wave (Boer et al., 1986; Deloij et al., 1986). The motion of one leg during skating involves a glide phase, a push phase, and a recovery phase (Allinger and Motl, 2000). The push phase is the only phase where the generation of velocity occurs.
Nothing herein is to be construed as an admission that the present invention is not entitled to antedate a publication by virtue of prior invention. Furthermore, the dates of publication where provided are subject to change if it is found that the actual date of publication is different from that provided here.

SUMMARY

One or more inventions are described herein. In one embodiment, a skate boot is provided that includes a foot portion configured to receive and secure a foot of a wearer. The skate boot includes a first tendon guard positioned proximal an Achilles tendon of a wearer of the skate boot, the first tendon guard being connected to the foot portion at a first articulation point and adjacent the foot portion along a medial abutment line and a lateral abutment line. The skate boot may optionally include a second tendon guard connected to the foot portion at a second articulation point and to the first tendon guard, the second tendon guard covering the first articulation point. In at least one embodiment, an elastomeric band is connected to the foot portion and to the first tendon guard and configured to bias the first tendon guard to a closed position. In at least one embodiment, an electrical generator is provided to heat an ice skate interconnected to the skate boot.
It is to be understood that the present invention includes a variety of different versions or embodiments, and this Summary is not meant to be limiting or all-inclusive. This Summary provides some general descriptions of some of the embodiments, but may also include some more specific descriptions of certain embodiments. As used herein, “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
It is to be noted that the term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.
Various embodiments of the present invention are set forth in the attached figures and in the detailed description of the invention as provided herein and as embodied by the claims. It should be understood, however, that this Summary does not contain all of the aspects and embodiments of the present invention, is not meant to be limiting or restrictive in any manner, and that the invention as disclosed herein is and will be understood by those of ordinary skill in the art to encompass obvious improvements and modifications thereto.
Additional advantages of the present invention will become readily apparent from the following discussion, particularly when taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the below and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1A illustrates an embodiment of an articulating tendon guard from a sagittal view according to one embodiment of the invention.

FIG. 1B is a rear view of the articulating tendon guard illustrated in FIG. 1A.

FIG. 2A is a top view of the primary tendon guard and neoprene strap of the embodiment of FIG. 1A.

FIG. 2B is a sagittal view of the primary tendon guard and neoprene strap of the embodiment of FIG. 1A.

FIG. 3A illustrates a an articulating tendon guard from a sagittal view according to a further embodiment of the invention.

FIG. 3B is a rear view of the articulating tendon guard illustrated in FIG. 3A.

FIG. 3C is another sagittal view of the embodiment of FIG. 3A. In FIG. 3C the skate boot is illustrated with the tendon guards in an ankle plantar flexed position.

FIG. 4A illustrates an articulating tendon guard according to another example embodiment of the invention.

FIG. 4B is a sagittal view of the articulating tendon guard of FIG. 4A with the tendon guards in an ankle plantar flexed position.

FIG. 4C is a sagittal view of the articulating tendon guard of FIG. 4A with the tendon guards in an ankle dorsi flexed position.

FIG. 5 is a photograph of the Graf Supra 703 (left), and the CCM 952 Super Tacks (right), showing maximal ankle extensions (plantar flexion). The ankle joint axis is marked by dot 18, and the knee joint axis is marked by a dot 19.

FIG. 6 is a photograph of the Graf Supra 703 modified for the ankle extension (left), and the CCM 952 Super Tacks modified with a removed upper tendon guard (right), showing maximal ankle extension (plantar flexion). The ankle joint axis is marked by a dot 18, and the knee joint axis is marked by a dot 19.

FIG. 7 is a photograph of a bare foot showing three successive ankle extension positions. The ankle axis of rotation is marked by a dot 18.

FIG. 8 is a photograph of a VH stock custom speed skate showing maximal ankle extension (plantar flexion). The ankle joint axis is marked by a dot 18, and the knee joint axis is marked by a dot 19.

FIG. 9 is a schematic of a speed skating push with the pivot point positioned in the same place as the end of the hockey skate blade, and a schematic of a hockey skating push. Rigid links were created between the hip joint, knee joint, ankle joint, and the point where rotation of the foot occurs (pivot point) for biomechanical analysis.

FIG. 10 is photographs showing the data collection set up in the laboratory.

FIG. 11 is a graph showing the final center of mass velocity for a simulated skating push with a conventional hockey skate and the ankle extension skate. Data presented are averages with 95% confidence intervals for ten subjects.

FIG. 12 is a graph showing the ankle energy generated during the explosive push phase for a simulated skating push with a conventional hockey skate and the ankle extension conversion skate. Data presented are averages with 95% confidence intervals for ten subjects.

FIG. 13 is a diagram of the gliding direction of the pushing skate, final CM velocity vector, and the component of the CM velocity vector in the direction of forward motion for the ankle extension conversion skate and the traditional hockey skate.

FIG. 14 is a diagram representing the movement of two hypothetical hockey players skating maximally towards a puck 12.27 m away. Player 1 represents a player wearing the ankle extension conversion skate. Player 2 represents a player wearing a traditional hockey skate.

FIG. 15 is photographs of the Graf Supra 703 unmodified, and modified for the ankle extension, during maximal eversion and inversion of the ankle joint. Photographs were taken from the frontal view. The center of the ankle joint axis is marked by a dot 18, and the center of the knee joint axis is marked by a dot 19.

DETAILED DESCRIPTION

Reference will now be made to the drawings to describe various aspects of exemplary embodiments of the invention. It is to be understood that the drawings are diagrammatic and schematic representations of such exemplary embodiments, and are not limiting of the present invention, nor are they necessarily drawn to scale.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known aspects of skate boots have not been described in particular detail in order to avoid unnecessarily obscuring the present invention.
With reference now to FIGS. 1A and 1B, according to a first example embodiment of the invention an articulating tendon guard uses a neoprene lower leg strap 5 to connect the articulating tendon guard to the lower leg of a wearer. In one embodiment the skate boot has two cuts 2 angled distally towards the ankle axis of rotation, forming the tendon guard 1 between them. The two cuts meet approximately 20 mm shy of each other at the point of articulation 3. The point of articulation is along the same horizontal axis as the ankle joint center and therefore allows complete unrestricted plantar flexion of the ankle joint. An elastomeric band 4 is inserted between the inner and outer layers of the upper and sewn in place. The elastomeric band 4 crosses the cut 2 and provides recoil of the tendon guard 1, after ankle extension. Also, to ensure adequate recoil of the tendon guard 1 a lower leg strap 5, which may be made of neoprene for example, is preferably adhered and stitched 6 to the tendon guard. In one embodiment the strap 5 fastens to the lower leg by a hook and loop attachment 7 on the anterior side of the leg (shin), as illustrated in FIGS. 2A and 2B.
In one example embodiment of the invention the tendon guard is formed by modifying an existing skate boot by cutting the skate boot at cuts 2 and adding the lower leg strap 5 and elastomeric band 4. In another example embodiment the tendon guard is formed separately from the skate boot and attached thereto at articulation point 3 by a method known in the art of connecting the selected materials.
Another example embodiment of the invention is illustrated in FIGS. 3A, 3B, and 3C. In this embodiment a lower leg strap 5 may optionally be omitted while a secondary tendon guard 10 is added to help protect the articulation 3 of the primary tendon guard 1. The secondary tendon guard 10 is also preferably biased to assist in recoil of the primary tendon. The secondary tendon guard 10 articulates at a point 8 that is between 1 cm and 5 cm below the articulation of the primary tendon guard 3. The secondary tendon guard 10 is attached to the primary tendon guard 1 at point 9 with a connector such as a rivet, bolt and t-nut, and the like.
With reference now to FIGS. 4A-4C, in yet another example embodiment of the invention electrical generation components are added to moving parts in the skate boot so that current can be conducted to the blade where resisters will convert the electric current into heat. It has been shown that heated blades glide 50-75% better than non-heated blades due to reduced ice friction. Electrical generation component 12 generates a current when component 13 slides over it as the tendon guards are extended and then recoiled. Electrical generation component 15 also generates a current when component 14 slides over it as the tongue is flexed forward and then recoiled. The current that is generated is conducted along the wire 16 and is converted into heat by the resistors 17 that lie in small recesses in the skate blade.
The following Performance Comparison describes attributes of an embodiment of the present invention in comparison to another device.

Performance Comparison

1. Biomechanical and Performance Aspects of a Skate in Accordance with at least one Embodiment of the Present Invention
The Performance Comparison looked at the performance effects of increasing ankle joint range of motion during the skating push with certain modifications to the tendon guard (ankle extension). The purposes of this investigation were:
To compare the total amount of push energy and center of mass velocity generated during a skating push with the constraints of a conventional hockey skate versus that with the reduced constraints of a hockey skate that incorporates the new ankle extension. These results will then be related to actual skating kinematics.
To determine if the ankle extension has any deleterious effects on ankle support, stability, and protection.
Data collection consisted of two parts. The first part was a detailed analysis of angular energetics and center of mass movement during the push phase of a simulated skating push. Data were collected on ten subjects in the laboratory while the subjects performed a maximal effort skating push on a modified slide board apparatus. The second part of the investigation consisted of two case studies that tested prototypes of the ankle extension, on the ice. The case studies involved digital picture analysis of ankle inversion and eversion, along with anecdotal feedback.
The lab testing indicated that there was a strong positive influence, of the increased ankle range of motion allowable with the ankle extension, on skating performance. It was shown that the increased energy generation per push resulted in a higher final velocity of the center of mass during the push phase. It was further shown that the increased velocity would have a significant effect on hockey skating performance.
The case studies revealed no decrease in ankle support and stability, with positive anecdotal feedback relating to the matter.

2. Introduction

The skate boot embodiment analyzed in this testing has a tendon guard that allows a much larger range of motion at the ankle joint than what is currently allowed with conventional hockey skate boots. The ankle extension allows for a larger range of motion through increased ankle extension. It was speculated that this increased ankle joint extension would result in higher energy generation and a slight elongation of the push, resulting in increased acceleration and maximal skating velocity.
Purpose
To compare the total amount of push energy and center of mass velocity generated during a skating push with the constraints of a conventional hockey skate versus that with the reduced constraints of a hockey skate that incorporates the new ankle extension. These results will then be related to actual skating kinematics.
To determine if the ankle extension has any deleterious effects on ankle support and stability.

3. Methods

Data collection consisted of two parts. The first part was a detailed analysis of angular energetics and center of mass movement during the push phase of a simulated skating push. The second part of the investigation consisted of two case studies.

Skates

The hockey skates analyzed were the Graf Supra 703 and the CCM 952 Super Tacks. All skates were commercially available and modified for analysis after purchase. The Graf Supra 703 skates were initially analyzed for maximal extension angle (FIG. 5), and subsequently modified for the ankle extension and tested for maximal extension angle (FIG. 6). The CCM 952 Super Tacks were initially analyzed for maximal extension angle (FIG. 5), and subsequently modified for an increased range of motion (FIG. 6), to mimic what has been done commercially to allow for increased ankle extension (i.e. Graf727, Bauer Supremes, Mission Super Fly). An uninhibited foot was analyzed for anatomical extension characteristics (FIG. 7). A VH Stock Custom speed skate boot was also analyzed for maximal extension angle to provide accurate comparison information between the collected data and the hockey skates (FIG. 8).
FIG. 5 shows an ankle extension angle of 106.5°. This angle was believed to be the common extension angle with conventional hockey skates. FIG. 6 shows an extension angle of 122° for the ankle extension. Even in FIG. 6 where the upper tendon guard is removed from CCM 952 Super Tacks an extension angle of only 110.5° could be achieved. The reason for the 11.5° larger extension angle can be clearly seen in FIG. 7, where rotation occurs through the ankle axis. The ankle axis of rotation runs approximately through the malleoli (ankle bones). It can be clearly seen that any rigid structure extending vertically above the ankle axis will inhibit ankle extension, and prematurely end the skating push. Therefore, even with the upper tendon guard cut (FIG. 6) the lower portion of the tendon guard is still too high to allow full ankle range of motion. With the ankle extension the cut in the tendon guard is angled distally towards the ankle axis of rotation, allowing for a less inhibited ankle extension, and a longer skating push. FIG. 8 shows an ankle extension angle of 137°, the maximum allowable with a speed skate. This information was used to extrapolate a skating push with a conventional hockey skate and a hockey skate with the ankle extension from the data.

Subjects

A total of ten male subjects participated in this study. All subjects were elite level speed skaters. All subjects were free from recent lower extremity injury or pain. Informed written consent in accordance with the University of Calgary's Research Ethics Board was obtained from all subjects.

Angular Energetics and Center of Mass Movement

Angular energetics and center of mass (CM) movements were determined on all ten subjects while using their own klap speed skates. The klap skate pivot point (point of foot rotation) was positioned in the same place as the end of the hockey skate blade, to create similar pushing mechanics (FIG. 9).
The push phase was analyzed on a modified slide board apparatus to greatly reduce the errors associated with on-ice kinetic and kinematic testing; exact testing methodology used by Van Home and Stefanyshyn. The modified slide board model was set up as follows: a 20 foot by 4 foot melamin sheet had a small block of wood at one end where the subject performed the simulated skating push, from this point the subject slid along the board until friction stopped him. The slide board was bolted to a force platform, and was surrounded by seven high-speed digital cameras, at the location of the board where the pushes occurred. The pushing foot was in a speed skate that had a protective low resistance material under the blade, so that the blade and slide board was not damaged. The contrilateral foot was clad in a running shoe covered with a wool sock. Ten maximal pushes were executed by each subject.
The start of the push phase was defined as the instant when the knee angular velocity exceeded 90 deg/s, a value previously used in the literature to identify the start of the explosive push phase (Houdijk et al., 2002). The end of the push phase used to simulate the conventional hockey skate push was at the instant when the ankle reached an extension angle 30.5° less than the maximal ankle angle achieved during the actual push (137°−106.5°=30.5°), that was executed with a klap speed skate. The end of the push phase used to simulate a hockey skate push with the ankle extension conversion was at the instant when the ankle reached an extension angle 15° less than the maximal ankle angle achieved during the actual push (137°−122°=15°) that was executed with a klap speed skate.
Maximal ankle extension angle is the factor that affects the push termination because beyond 110° of ankle extension the knee joint, even though still extending, is producing negative power (absorbing energy) (Houdijk et al., 2002; Van Home & Stefanyshyn). Therefore, the ankle is the only joint that can continue to contribute and elongate the push. If ankle extension is stopped the push will be terminated.
Kinetic data were collected with a force platform (Kistler, Winterthur, Switzerland) sampling at 2400 Hz, which was underneath and attached to the slide board. Kinematic data were collected simultaneously using a multiple video camera system (Motion Analysis Corp., Santa Rosa, Calif.) sampling at 240 Hz. Three reflective markers (1 cm diameter) were placed on each of the boot, the shank and the thigh for kinematic data collection (FIG. 10). Anthropometric data collected included the subject's height and mass and were used to determine inertial parameters from Clauser et al (1969). Three-dimensional coordinates of each of the markers were quantified (Expert Vision Analysis, Motion Analysis Corp., Santa Rosa, Calif.) and the movement within the specific two-dimensional planes of interest were then calculated.
A two-dimensional sagittal plane analysis was performed after smoothing both the video data (fourth-order low-pass Butterworth filter with a cutoff frequency of 10 Hz) and the force data (fourth-order low-pass Butterworth filter with a cutoff frequency of 100 Hz). Resultant joint moments were determined using inverse dynamics and then used to calculate joint power by taking the product of the resultant joint moment and the joint angular velocity (Winter, 1987). Energy was determined by integration of the joint power curve. Energy absorption occurs when the resultant joint moment is opposite in direction to the angular velocity. Energy production occurs when the resultant joint moment is in the same direction as the joint angular velocity. For this study, energy productions at the ankle, knee, and hip joints were determined. Paired t-tests (p=0.05) were used to analyze the data for significance.
Whole body center of mass positioning and movement were determined from the right foot, right shank, right thigh, and torso center of mass (CM) positioning and movement. Pilot testing showed very close agreement between this calculation and CM movement determined from whole body tracking.

Case Studies

Two subjects (proficient hockey players) with similar foot size and shape skated on prototypes of the ankle extension. Frontal view digital pictures were taken during maximal ankle eversion and inversion with the Graf Supra 703 before and after the ankle extension conversion. The images were analyzed for maximal eversion and inversion angles to quantify whether the ankle extension conversion reduced ankle support. Anecdotal accounts were taken for ankle stability qualification.

4. Results and Discussion

Angular Energetics And Center Of Mass Movement

There was a significant difference between the simulated final CM velocity of the push with the conventional hockey skate and the ankle extension skate (FIG. 11). The ankle extension conversion skate had a final CM velocity of 2.83 (±0.045) m/s. The conventional hockey skate had a final CM velocity of 2.66 (±0.045) m/s.
The reason for the higher final CM velocity with the ankle extension conversion skate was that the push took 0.018 seconds longer to execute, which allowed for more energy to be generated at the ankle joint. The simulated push with the ankle extension conversion skate produced significantly more energy at the ankle (9.67 J) than the conventional hockey skate (FIG. 12). It should be noted that the increased push time did not allow for an increase in the knee energy generated because during the final 0.05 seconds of the push the knee does not generate positive energy (Houdijk et al., 2000; Van Home & Stefanyshyn).
The following example will show the effects of the 0.17 m/s higher CM velocity, that could potentially be generated with the ankle extension conversion skate, in an actual hockey game scenario.
Assuming the direction of glide of the pushing skate is at 30° to the longitudinal direction of the skating path (direction of forward motion) the contribution of the push to forward motion velocity can be easily calculated (FIG. 13). During the acceleration phase of skating an elite hockey player takes approximately 0.462 seconds per stride (glide phase, push phase, and recovery phase). Therefore, if the push phase for the ankle extension conversion skate is 0.018 seconds longer, then a player using that skate would take approximately 0.480 seconds per stride. Knowing the time duration of the stride and the acceleration per stride, with certain simplifying assumptions, one could calculate the following problem.
Problem: how much faster would Player 1 (wearing the ankle extension conversion skate) get to a puck that is 12.27 m away than Player 2 (wearing a traditional hockey skate)? Assuming both players start from a stand still at the exact same position. Also, assuming that both players are physiologically identical, and their power per stride and stride frequency remain constant through out the 12.27 m. The problem is answered in the diagram presented in FIG. 14.

Case Studies

There was no change in maximal eversion and inversion angles of the ankle joint when the frontal plane digital still pictures were analyzed (FIG. 15). This indicates that the medial/lateral support was not compromised with the ankle extension conversion. The anecdotal claims support these findings.

5. Comments

The ankle extension allowed for a 15.5° larger range of ankle joint motion than the traditional hockey skate through increased ankle extension. Through simulations, this increased ankle extension was shown to allow a skater to generate 9.67 J more energy at the ankle joint during the push phase. This translated into a higher final center of mass velocity during the push phase. In a hypothetical scenario where two players were racing for a puck 12.27 m away the player with the ankle extension skate reached the puck 0.04 seconds sooner than the player with traditional hockey skates. A 0.04 second time advantage at a velocity of 8.52 m/s translates into a distance of 34 cm, more than enough distance to gain control of the puck.

6. Description of the Ankle Extension

The ankle extension is a tendon guard with the addition of a neoprene lower leg strap (FIGS. 1A, 1B, 2A, and 2B). The tendon guard [1] has two cuts [2] angled distally towards the ankle axis of rotation. The two cuts meet approximately 20 mm shy of each other at the point of bending [3]. An elostomeric band [4], that is inserted between the inner and outer layers of the upper and sewn in place, crosses the cut [2] and provides recoil of the tendon guard [1], after ankle extension. Also to ensure adequate recoil of the tendon guard [1] a neoprene lower leg strap [5] is adhered and stitched [6] to the tendon guard. The neoprene strap [5] fastens to the lower leg by a hook and loop attachment [7], on the anterior side of the leg (shin).
The advantage of the ankle extension over previous embodiments is simplicity, effectiveness, and comfort. Very little adjustment to the traditional manufacturing process is needed to build the new skate into a traditional hockey skate: two cuts and four stitch-lines need to be added. The new skate allows for increased ankle joint extension without any detriment to support or stability. With the addition of the neoprene lower leg strap the wearer feels increased comfort, and the tendon guard stays within a closer proximity to the achilles tendon throughout the range of motion, increasing protection.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A skate boot, comprising:

a foot portion configured to receive and secure a foot of a wearer;

an articulating tendon guard positioned proximal an Achilles tendon of the wearer of the skate boot, the articulating tendon guard being connected to the foot portion at an articulation point and adjacent the foot portion along a medial abutment line and a lateral abutment line; and

an elastomeric member connected to the articulating tendon guard and connectable to a lower leg of the wearer; and

an elastomeric band connected to the foot portion and to the articulating tendon guard and configured to bias the articulating tendon guard to a closed position where the articulating tendon guard abuts the foot portion long the medial abutment line and the lateral abutment line.

2. A skate boot, comprising:

a foot portion configured to receive and secure a foot of a wearer;

a first tendon guard positioned proximal an Achilles tendon of a wearer of the skate boot, the first tendon guard being connected to the foot portion at a first articulation point and adjacent the foot portion along a medial abutment line and a lateral abutment line;

a second tendon guard connected to the foot portion at a second articulation point and to the first tendon guard, the second tendon guard covering the first articulation point; and

an elastomeric band connected to the foot portion and to the first tendon guard and configured to bias the first tendon guard to a closed position where the first tendon guard abuts the foot portion long the medial abutment line and the lateral abutment line.

3. An ice skate, comprising:

a foot portion configured to receive and secure a foot of a wearer;

a first tendon guard positioned proximal an Achilles tendon of the wearer of a skate boot, the first tendon guard being connected to the foot portion at a first articulation point and adjacent the foot portion along a medial abutment line and a lateral abutment line;

a second tendon guard connected to the foot portion at a second articulation point and adjacent to the first tendon guard, the second tendon guard covering the first articulation point; and

an elastomeric band connected to the foot portion and to the first tendon guard and configured to bias the first tendon guard to a closed position where the first tendon guard abuts the foot portion long the medial abutment line and the lateral abutment line

an electrical generator, comprising:

a first electrical generation component connected to the first tendon guard;

a second electrical generation component connected to the second tendon guard, wherein movement of a leg of the wearer forwards and backwards moves the first electrical generation component with respect to the second electrical generation component, thereby generating an electrical current;

the ice skate connected to the skate boot; and

a plurality of resistors connected to the ice skate and configured to receive the electrical current from the electrical generator to thereby generate heat and heat the ice skate.