Pressure Measurements on Amputee’s Residuum in Classification for Standing Ice Hockey
Mark Pitkin1, Ludmila Smirnova2, Konstantin Scherbina2, Sergei Kurdybailo2, Sergei Evseev3 and Nikolai Maslov4
1Tufts University, Boston, MA, USA,
2Albrecht Rehabilitation Center, St. Petersburg, Russia
3State Research Institute of Physical Culture and Sport, St. Petersburg, Russia
4Ice Hockey Olympic School, St. Petersburg, Russia
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Abstract
Direct measurements of pressures on the residuum were performed in three subjects unilateral below-knee amputees during ice practices of the Russian national standing ice hockey team. Data were collected using Tekscan technology. A hypothesis was evaluated that when pressures on the stump decrease, a subjective feeling of comfort will increase. The hypothesis was confirmed during skating and walking. During extensive jumping, a reverse effect was observed in one subject. Namely, pressures on the residuum during jumping were lower than in walking and skating, when he felt more comfort. Additional trials were conducted with simultaneous recording of the pressures on the residuum and under both the involved and uninvolved feet with Tekscan F-scan sensors. It was found that pressures under the uninvolved foot during jumping were significantly higher than during walking and skating, indicating that the subject loaded more his uninvolved leg to prevent the overloading of his residuum. This result leads to the assumption that an athlete can increase the loading of the residuum at the demand of playing tasks, but only if the loading won’t reach a certain threshold associated with the exceeding pain and discomfort. It is suggested to investigate further this phenomenon for a more objective classification in standing ice hockey.
Introduction
Standing Ice Hockey is a rapidly growing new adaptive sport discipline [1]. An outline of the classification for standing ice hockey was made in 2001 by Professor Sergei Evseev [2]. Due to the collective efforts of the national member associations participating in the First (2003) and Second (2004) World Championships of the International Standing Ice Hockey Federation (ISIHF), the current classification was adopted by the ISIHF Congress [3] and recently amended. Further improvement of standing ice hockey classification ought to be conducted using the outcomes of biomechanical studies, which allow for more objectivity and consistency in team selection
Methods
Direct measurement of pressures and forces applied from a prosthetic socket to an amputee’s residuum was chosen for comparison of an athlete’s performance during skating and walking [4]. The current study was conducted at the Spartak Ice Arena, St. Petersburg, Russia, to compare loads on an amputee’s residuum during skating, walking, and jumping. Three subjects, unilateral below-knee amputees, members of the Russian national amputee hockey team, were asked to skate in one and the opposite direction for about 10 meters, making turns at a speed comfortable to them. After 3-4 trials on ice, subjects were asked to perform the same task, but wearing athletic shoes while walking on a wooden floor. Subjects skated and walked with their own prosthetic foot. The locations of the four sensors attached to the residuum were not changed.
Peak pressures on each sensor were collected every 1/60 of a second. Data were exported to format for further analysis. For every trial, we identified five greatest maximal values in peak pressure series from each of the four sensors. The mean maximal values were compared respectively after linear skating, and after walking and jumping. Indexes of performance in skating relative to walking ( ), skating relative to jumping ( ), and walking relative to jumping ( ) were calculated as a ratio of mean maximal pressures of all push-offs or steps during a given trial vs. mean maximal pressures of all push-offs or steps during a base walking trial chosen for comparison.
Results
Recordings of the peak pressures are presented in Figure 2. Data are grouped to allow for qualitative comparison of the pressures on the four sensors during skating, walking and jumping correspondingly. A quantative comparison is presented in the Table 1.
Table 1. Comparison of the averaged maximal values of pressure (raw data) recorded on the anterior, posterior, lateral and medial sensors during skating, walking and jumping
Parameters |
Position of the sensors on the residuum |
Anterior |
Posterior |
Lateral |
Medial |
Mean maximal pressures during skating ( M 5 ) |
33713.3 |
20917.7 |
26538.0 |
31447.0 |
Mean maximal pressures during walking ( M w ) |
28213.3 |
37975.3 |
27054.7 |
24393.3 |
Mean maximal pressures during jumping ( M j ) |
58478 |
44316 |
35016 |
43048 |
Index of skating relative to walking ( M 5 / M w ) |
1.194943 |
0.550822 |
0.9809 |
1.2892 |
Index of skating relative to jumping ( M 5 / M j ) |
0.576513 |
0.472012 |
0.7579 |
0.7305 |
Index of walking relative to jumping ( M w / M j ) |
0.482461 |
0.856922 |
0.7726 |
0.5667 |
According to the data in Figure 2 and Table 1, skating demonstrated a significant lowering of maximal peak pressures on posterior and anterior surfaces of the residuum compared to walking. Peak pressures on the three other sensors didn’t demonstrate significant difference between skating and walking. Peak pressures during jumping were significantly higher on anterior and posterior sensors compared to skating, and on anterior and medial sensors compared to walking.
A single deviation from these results was observed during one jumping trial in one subject. Namely, pressures on the residuum during jumping were lower than in walking and skating. To analyze this phenomenon, additional trials were conducted with simultaneous recording of the pressures on the residuum and also under both involved and uninvolved feet with Tekscan F-scan sensors. It was found that pressures under the uninvolved foot during more extensive jumping were notably higher than during waling and skating, indicating that the subject loaded more his uninvolved leg to prevent the overloading of his residuum.
Peak Pressure vs. Time (raw data) |
Frames corresponding to the max peak pressure on the sensors |
skating |
walking |
jumping |

Figure 2. Recordings of peak pressure vs. time on the anterior, posterior, lateral and medial sensors during skating, walking and jumping.
Discussion
The acceptable level of amputees’ comfort during hockey play results from both skating biomechanics and specifics of this team sport. First, there is relatively low energy expenditure during skating and gliding, as compared to other competitive sports, such as cycling [5]. Secondly, the most frequently performed skills during the game are skating forward without the puck and gliding forward without the puck [6]. The players are exposed to relatively high peak pressures associated with maneuvering for quite a small time. For the rest of the time, they are gliding and skating forward, thus experiencing, as our study demonstrated, more comfort (less pain) than while walking (if players wear the multi-axial prosthetic foot and ankle).
Another reason for the relatively high level of acceptance of standing ice hockey by amputees is the generally lower speed of skating, since the inherently slower speed decreases impact during checking. Preliminary analysis of video data give an estimate of 30% lower speed in amputees with leg prostheses compared to able-bodied players. More studies on speed of skating are required, especially for classification purposes in the teams with lower limb amputees playing together with upper limb amputees, whose speed is significantly higher. The overall results of the study suggest that amputees can participate in a highly motivational and active sport without excesses in pressure peaks on the stump for the larger part of the game.
Specifically, the results of this study demonstrated that peak pressure during skating and walking were reasonably compatible, and were lower compared to jumping. That contributes to an explanation of why standing ice hockey has become so popular in many countries, and why the players continue to play this sport with motivation.
A trial in one subject with the reverse effect during extensive jumping deserves serious attention as well. This trial shows that an athlete can increase the loading of the residuum at the demand of the playing tasks, but only if the loading won’t reach a certain threshold associated with the exceeding pain and discomfort.
It is suggested to investigate further this “pain preventive” phenomenon, which might serve as a threshold for safe loading in sports, specifically in standing ice hockey. It can be a candidate for a more objective parameter to be used in classification.
Practical Implications
Direct pressure measurements on the athlete’s residuum provide meaningful information on the distinction between the tasks being compared. The methodology can be used in the future for the development of a more objective classification in standing ice hockey.
Acknowledgements
Support for the study was provided in part by the CRDF Grant RB1-2382-ST-02. The authors extend their gratitude to the members of the Russian national standing ice hockey team, the Ohio Willow Wood Co., Mt. Sterling, OH, and Tekscan Inc., Boston, MA.
References
[1]. Pitkin, M., International service delivery. J Rehabil Research Development, 2002. 39(3): p. 17-8.
[2]. Evseev, S., Hockey on prostheses. Sports-medical classification. Vestnik Gil'dii Protezistov Ortopedov (Journal of Russian Guild of Prosthetists and Orthotists), 2001. 6(3).
[3]. ISIHF, Second World Amputee Ice Hockey Championship. 2004: p. 6.
[4]. Pitkin, M., et al., Comparison of Pressure on Residuum During Gait and Skating in Transtibial Amputees Hockey Players, in 11th ISPO World Congress, August 1-6. 2004: Hong Kong.
[5]. Kandou, T., et al., Comparison of physiology and biomechanics of speed skating with cycling and with skateboard exercise. Can J Sport Sci, 1987. 12: p. 31-6.
[6]. Braccesi, C., et al., The method of finite elements in evaluation of the mechanical behavior of the Ilizarov apparatus. Arch Putti Chir Organi Mov, 1989. 37(1): p. 97-105.
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Pressure Measurements on Amputee's Residuum in Classification for Standing Ice Hockey
Mark Pitkin1, Ludmila Smirnova2, Konstantin Scherbina2, Sergei Kurdybailo2, Sergei Evseev3 and Nikolai Maslov4
1Tufts University, Boston, MA, USA,
2Albrecht Rehabilitation Center, St. Petersburg, Russia
3State Research Institute of Physical Culture and Sport, St. Petersburg, Russia
4Ice Hockey Olympic School, St. Petersburg, Russia
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