Chapter 10. Design and Materials in Ice Hockey

CHAPTER Design and Materials in Ice Hockey
D. Pearsall and S. Robbins
McGill University, Montreal, QC, Canada INTRODUCTION
The origins of ice hockey date back to the sin Canada and Europe.
Since then, it has evolved into a fast-paced game with international appeal. In addition to increasing popularity, ice hockey has become increasingly sophisticated in terms of technological innovations, equipment design, and improvements in training, coaching, and game strategies.
Due to the specialized environmental conditions (e.g., low surface friction, ice hockey requires a unique skill set. These skills can be subdivided into general categories of skating, shooting, and checking. The intent of this chapter is to examine the design of ice hockey skates and sticks ICE HOCKEY SKATE DESIGN
The modern skate design has evolved primarily as a result of trial and error on the part of designers in the ice hockey industry.
Fig. shows the basic features and appearance of modern skate. Most ice hockey skate boots are designed using leather and synthetic materials. Designers desire to optimize durability, performance, comfort, and fit for the skater. The amount of each type of material used, including materials such as Kevlar
(Dupont) and graphite, depends on the quality of the skate. Recent designs include a molded hard plastic boot that offers good protection against blows from sticks and pucks. This type of skate can also provide a great deal of support for the skaters ankles. Some recent designs using hard molded skates respect the foot anatomy more closely and may offer better kinesthetic awareness during skating maneuvers.
The skate has a history that originates from activities unrelated to the sport of ice hockey. During the age of the Renaissance, it has been documented that individuals used carved animal bones strapped to their boot
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DOI:
https://doi.org/10.1016/B978-0-08-102582-6.00010-1
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Figure 10.1 Depiction of atypical modern ice hockey skate.

soles as skates. Old paintings dating back to the s depict individuals skating on ice with this early skate model (
Koning, Houdijk, Groot, &
Bobbret, 2000
). Some of these early skating scenes were observed in
Scandinavia. By the late s the use of bones as blades was replaced with metal blades strapped to a wooden slab fitted to the sole of the boot.
A further modification included a complete metal blade which increased the weight but decreased skating speed (
Minkoff & Simonson, This was one of the first skate design modifications showing that changes to skate construction affected skating performance. Weight was decreased with the implementation of tubular skate blades in the sand by the
1960s and s blade ends were covered, increasing safety and the use of composite plastics like polyethylene resins, carbonates, and fiberglass with metal blade assemblies resulted in a further decrease in mass facilitating skating speed and maneuverability (
Pearsall, Turcotte, & Murphy, Thus these previous design changes demonstrate that the alterations of skate characteristics and materials can have an effect on the performance capabilities of the athlete.
Historically, there has been relatively little research conducted to elaborate on the effects of changes in skate design on skating performance.
Recent studies have been conducted in an effort to begin this process of characterization of the impact of specific skate design changes on comfort,
fit, and performance of ice hockey skating. Most of the work done in ice hockey has been what one might call
“reverse engineering since many products have been conceived by intuition and evaluated post hoc. In order fora skate design to provide optimal function, it would seem logical that a number of conditions must be met when evaluating the design. For skate design to be considered optimal a skate must. permit adequate kinesthetic sense of joint position and limb orientation. avoid pinching sensitive soft tissue areas overlying muscles and neuro- vascular structures. accommodate for geometric anthropometrics and orientation of bony structures. provide for effective anterior posterior and medial lateral alignment stability and range of motion. provide for effective forefoot and rear foot leverage for controlled blade movement, and. accommodate for the restriction of joint movements and coupled foot-ankle-knee-hip chain coordination.
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10.3 EVALUATING SKATE BOOT DESIGN
Skate boot design must provide a compromise between providing stiffness and protection while allowing range of motion. Often, these two goals are at odds. For example, a high-cut boot provides medial lateral support during turning tasks however, this could restrict plantarflexion and dorsi- flexion depending on the skate construction. A stiffer boot may enable the generation of appropriate forces both for support and for power generation during skating. The skate is likely used as a lever that helps support and generate force, and the dynamics of skating may preclude the use of the full anatomical range of motion of the ankle joint (
Turcotte, Pearsall,
& Montgomery, 2001
). Alternatively, increasing boot flexibility would permit additional range of motion, and this could aid in power generation.
Specifically, increasing ankle plantarflexion would potentially allow the calf muscles to generate more power. Therefore it appears that increased stiffness is desired in the medial lateral direction, while increased flexibility is desired in the anterior posterior direction. Research over the past two decades has examined both the impact of boot stiffness and flexibility on skating performance and comfort Analyzing and Improving Stiffness Properties of the
Skate Boot
It has been a common perception that a stiff skate offers better support and with the right materials also offers better protection. A previous study constructed a jig that made it possible to measure skate stiffness during the execution of simulated on-ice tasks (
Turcotte et al., 2001
). The jig was used to measure the load in Newton versus the extension in centimeter
(stiffness/rigidity modulus) in various movements including dorsiflexion,
plantarflexion, eversion, inversion, and medial and lateral torsion movements. Three different skate models were examined, and differences in stiffness values were consistent with the construction parameters. The results confirmed that it is possible to manufacture a
“stiffer” skate which was the goal of the equipment maker.
But several questions emerged from this study. Was such an increased stiffness truly desirable What effect does increasing stiffness have on the fit and comfort of the skate What are the possible advantages of increasing stiffness of the skate boot from a performance perspective Researchers have attempted to answer these questions using pressure-sensing technology.
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One such study examined the measured pressures (kPa) in various areas of the skate to document wherein the skate high pressures were experienced by athletes (
Gheorghiu, 2006
). Mapping of pressure patterns indifferent areas of the foot in this manner helped to determine whether the skate fit was appropriate and was suggestive of possible design changes that would improve fit by decreasing overall pressure hot points. A common problem of athletes is having a comfortable fit without the skate being too
“loose” so as to negatively affect a perceived snug fit of the skate. This study mapped pressure patterns and documented which areas of the foot exhibited the greatest and lowest pressure points with the present conventional modern skate design. Generally, greater pressures were on fifth metatarsal and medial malleolus, while lower pressures were on the Achilles tendon.
Also, the perception of pressure was negatively related to the perception of comfort. Such a study has important implications for determining the ideal fit for comfort and appropriate skate boot fit (
Gheorghiu, Performance might be impacted by boot stiffness, in addition to comfort and fit issues. The interface between the skate and foot and pressure generation has been examined (
McGrail, 2006
). Pressures were measured in various areas of the skate boot interface during the execution of a variety of skills such as tight turns, forward and backward crossovers, as well as forward skating in elite and recreational skaters. Elite skaters were able to generate higher peak pressures as well as higher pressures during both left and right turn initiation. Thus it appears that a greater leveraging of the lateral and medial parts of the skate is possible during the execution of turning motions if the skater is good enough to take advantage of the skates construction properties.
Therefore based on the differences between elite and recreational skaters, it would seem that the stiffness properties of the skate are an important aspect of the skate design. The stiffness of the skate in the medial and lateral parts of the boot offers much needed support during the execution of skating maneuvers and provides away of levering forces to support more rapid and powerful execution of these movements.
Good skaters seem capable of taking advantage of the special features built into the design of the top-line skate models Analyzing and Improving Skate Boot Flexibility
The previous section demonstrated that medial lateral stiffness is desired in a skate. However, research potentially indicates that increasing flexibility
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of the skate in the anterior posterior direction and permitting increased ankle dorsiflexion-plantarflexion would be beneficial. Recent skate designs have tried to accomplish this by including flexible tendon guards. This design is inspired by klapskates used in long track speed skating. Klapskates pivot near the forefoot. This allows increased plantarflexion during the end of push-off leading to increased power generation compared to conventional speed skates and, ultimately, leads to faster skating times (
Houdijk, de
Koning, de Groot, Bobbert, & van Ingen Schenau, 2000
). A number of studies have examined the ability of modified hockey skates or skates with flexible tendon guards to increase ankle motion and improve performance
(
Pearsall, Paquette, Baig, Albrecht, & Turcotte, 2012; Robert-Lachaine,
Turcotte, Dixon, & Pearsall, 2012; Tidman, Early studies investigated a modified skate where the Achilles tendon guard was removed. A pilot study compared the effect of modifying skate construction to eliminate some movement restrictions during forward skating. The pilot study showed an increase in dorsiflexion plantarflexion
(22 degrees modified vs 15 degrees standard skate) but a decrease in inversion eversion (7 vs 12 degrees) with the modified skate. However,
only one subject was evaluated in this pilot study. Another study compared a type of test skate with no support above the malleoli and showed that a variety of skate models were able to displace the ankle joint to the same extent as the test skate (
Hoshizaki, Kirchner, & Hall, This study revealed a similar range of motion in the test skate compared to the standard skate with dorsiflexion plantarflexion range of motion comparable at about 15 20 degrees (
Hoshizaki et al., 1989
). Differences in the test method may account for the disparity of observed range of motion that is, the latter study used D film analysis of external markers that would not necessarily detect foot ankle motion internal to the boot.
Tendon guards provide protection and thus removing them is not feasible. Flexible tendon guards might permit more ankle motion and still provide protection. Early work compared skates with a flexible tendon guard and standard skates while participants were seated on an isokinetic dynamometer (
Pearsall et al., 2012
). The dynamometer moved the skate through the available range of motion, and participants completed iso- kinetic strength tests. Higher combined ankle dorsiflexion plantarflexion range of motion (52.4 degrees) and a trend toward increased plantarflexion torque (64.2 N m) were found in the flexible tendon guard skates compared to standard skates (35.7 degrees, 62.7 N m) (Table 10.1
). There were no differences in the inversion eversion range of motion indicating
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that the flexible tendon guard skate had maintained medial lateral stiffness. A similar modified skate, which included a flexible tendon guard,
raised eyelets, and a flexible tongue was compared to a standard skate as adult, male skaters completed forward skating and crossovers on ice
(
Robert-Lachaine et al., 2012
). Ankle range of motion was measured with an electrogoniometer. The modified skate demonstrated increased dorsiflexion plantarflexion range of motion by 5 10 degrees during the skating tasks compared to the standard skate (Fig. 10.2
). Again, there were no differences in the inversion eversion motion between the skate types.
It is not clear if this increased dorsiflexion plantarflexion motion in the modified skate was due to the flexible tendon guard or the raised eyelet and flexible tongue. This latter skate modification could also conceivably increase anterior posterior skate flexibility. In contrast, another study found a decrease in dorsiflexion plantarflexion range of motion between flexible tendon guard skates (27.6 degrees) and standard (31.4 degrees)
skates in teen, male skaters (
Tidman, 2015
). Participants were skating on a skating treadmill, and joint angles were measured with a motion capture system. Differences in the skating surface, skate design, and player characteristics could account for the discrepancy between these studies.
Table 10.1 Difference in range of motion (ROM, torque, and work between a standard skate (SKATE) and a skate with a flexible tendon guard (SKATE FTG) during active dorsiflexion and plantarflexion
Dependent variables
Independent variable
Mean
SD
Significant difference (PROM (degrees)
SKATE FTG
52.4 SKATE vs SKATE FTG
SKATE
35.7 SKATE vs SHOE
SHOE
65.2 SKATE vs SHOE
Torque_Plantar
(N m)
SKATE FTG
64.2 SKATE vs SKATE FTG
SKATE
62.7 SKATE vs SHOE
SHOE
70.7 SKATE vs SHOE
Torque_Dorsi
(N m)
SKATE FTG
25.6 SKATE SHOE 5.5
Total_work
(kJ)
SKATE FTG
13.0 SKATE vs SKATE FTG
SKATE
8.9 SKATE vs SHOE
SHOE
16.0 SKATE vs SHOE
Source: Reprinted with permission from Pearsall, DJ, Paquette, Y. M, Baig, Z, Albrecht, J, &
Turcotte, RA. Ice hockey skate boot mechanics Direct torque and contact pressure measures. Procedia Engineering, 34, 295 Design and Materials in Ice Hockey

The impact of skate boot design on skating kinetics has also been examined. Strain gauges were able to determine that klapskates had increased power production at the end of push-off compared to standard speed skates (
Houdijk et al., 2000
). A similar approach has been used to examine whether flexible tendon guards skates with raised eyelets increased force production during a variety of skating tasks. Ina series of studies, strain gauges were placed in the blade holder allowing the comparison of vertical and medial lateral ground reaction forces between skate models (
Culhane, 2012; Forget, 2013; Fortier, Turcotte, & Pearsall,
2014; Le Ngoc, 2012; Robert-Lachaine et al., 2012
). During forward skating and crossover turns, there were no significant differences in ground reaction force variables over each stride between flexible tendon guard skates and standard skates in adult, male players (Fig. 10.3
) (
Robert-
Lachaine et al., 2012
). However, the total work and power over the entire task was 17% and 24% higher, respectively, for the flexible tendon guard skates, although this was not statistically significant. Likewise, there were no substantial differences in kinetics for these skate models during other skating tasks including starts, stop and go, and changing direction during skating, although the standard skates were occasionally associated
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