Amateur Athletic Union Taekwondo 2015 – 2016 AAU Taekwondo ...
The new design of movable target dummy device for taekwondo
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$554 Journal of Biomechanics 2006, Vol. 39 (Suppl 1) Poster Presentations validated by means of mechanical tests on physical prototypes produced on purpose. 7697 Mo-Tu, no. 47 (P61) The study of a new designed table tennis racket for training strike accuracy C.-'~ Peng, J.-L. Chen, T.-'~ Shiang. Taipei Physical Education College, Taipei, Taiwan The major movement of table tennis is striking the ball on racket to create high rebound speed. Sweet spot striking can create high rebound speed and easier control the ball as well as increase spin of the ball. But beginners can not know where on the racket they strike the ball even they can play the game well. In order to train the beginners to strike the ball in sweet spot and distinguish the impact accuracy, a new table tennis racket was designed using a common blade with two parts on the racket face. The sweet spot area remained normal material and surrounding area used cushioning material to absorb the impact energy to reduce the rebound speed. The character of the new racket design was when the ball strikes on the sweet spot, the ball can across the net. When the ball doesn't strike on the sweet spot, the ball can't across the net. A subject was asked to strike 90 balls for both forehand and backhand using this new racket. Results showed that the successful rate of sweet spot striking could reach almost 95%, the successful rate of non sweet spot striking could only reach 4%. Especially when using backhand strike in the non sweet spot, the successful rate could reach only 2%. As a conclusion that the new design training racket can effectively provide the feedback message for users. And the rackets can be used for training beginner or test the strike accuracy of player. 4741 Mo-Tu, no. 48 (P61) The new design of movable target dummy device for taekwondo C.-J. Lee 1, W.-H. Ho 2, A.-B. Chen 3. 1Institute of Sports Equipment Technology, Taipei Physical Education College, Taipei, Taiwan, 2Institute of Sports Technique, Taipei Physical Education College, Taipei, Taiwan, 3Department of Technique Sports Science, Taipei Physical Education College, Taipei, Taiwan. The traditional Tae Kwon Do practicing device appears in the form of a fixed target dummy or a punching bag. However, both forms can not accurately react to active attacks or continuous passive attacks from a real opponent in a match. Accordingly, the research intends to develop a movable target dummy with motor-driven steel wires to simulate the forward or backward movement of an adversary. This fighting art device is adjustable in height to suit the different heights of athletes, and is equipped with force sensors that will collect team members' kicking force. This research divided 8 A-grade male Tae Kwon Do members into 2 groups - superior and general - for kick testing of the reciprocating action performances. At a speed of 2 m/s, while the other group kicked 7.2±0.69 and 5.47±2.29 number times. These testing results successfully meet our purpose in providing immediate feedback to coaches about athletes' performance. The research aims to develop a movable Tae Kwon Do target dummy that can replicate the fighting mode in contest, and to upgrade the present contest training machine in order to provide Tae Kwon Do players with effective training and evaluating equipment. 4838 Mo-Tu, no. 49 (P61) Development of a foot-to-foot impedancemeter for measuring body composition during exercise M.-V. Moreno 1, H. Mehalebi 1, G. Baquet 2, D. Thevenet 3, EX. Gamelin 2, S. Berthoin 2, M.'~ Jaffrin 1. 1Dept of BioL Engineering, UMR-CNRS 6600, Tech. University of Compiegne, France, 2Laboratory of human motricity (EA n°3608), Dept. of sport science, University of Lille 2, France, 3Laboratory of Motricity, Interactions, Performance (JE n°2438), UFR STAPS of Nantes, France Foot-to-foot impedancemeters (FFI) are cheaper, simpler and quicker to use than medical type impedancemeters. The purpose of this work was to increase the functions of a prototype FFI derived from a commercially available FFI (Tefal Bodymaster Vision,Rumilly, France)with performing electronics, in order to obtain extracellular (ECW), total body water (TBW) volumes, body cell mass (BCM) and muscle mass in addition to weight and fat-free mass. A modification of the FFI permitted also to use it with hand and feet reusable electrodes. ECW and TBW measurements with the FFI were achieved by comparison with measurements made using a multifrequency medical impedancemeter Hydra 4200 (Xitron Tech, San Diego) and Dual X ray absorptiometry and appropriate modifications of the bioimpedance spectroscopic (BIS) method (1, 2). For BCM and muscle mass, we used Kotler's and Wang's methods re- spectively to relate them to the total body potassium concentration TBK as BCM =0.0083TBK, Muscle mass =0.0093TBK+0.024Age-3.21, where TBK is expressed in terms of Xcp, the equivalent reactance at 50 kHz, the subject height H, and his weight W. These methods were applied on a group of 52 children: 12 controls did not practice exercise, 20 jogged intermittently and 20 jogged regularly for three months. Changes in all the physiologic parameters listed above during this period as well as improvement in running speed for the three groups were compared and will be reported. With further development, this FFI prototype, which is easy to use and has indefinitely reusable electrodes, can be particularly useful in training and sport centers. References [1] Jaffrin MY, Kieffer R., Moreno M-V. Nutrition 2005; 21: 815424. [2] Fenech M, Jaffrin MY, Dabaja Z. Arch. Phys. Biochem. 2003; 111 : 20. 5216 Mo-Tu, no. 50 (P61) How long do insoles last: a simulation study? C. Birudavolu, G. Arnold, T. Drew, R. Abboud. Institute of Motion Analysis & Research (IMAR), University of Dundee, Scotland, UK Shock absorbing insoles have proved to be effective in the treatment of various foot pathologies. Many studies in the past have evaluated the efficacy of insoles with considerable discrepancy in their outcomes with most conducted using new insoles. Very few studies looked at the long-term performance of insoles after prolonged usage. This study aimed to assess the mechanical properties of commonly used insole materials under normal simulated use. The objectives were to investigate the rigidity/compliancy and shock absorbency of each material over a period of 50,000 cycles of repeated compressions using a Universal Testing Machine. Six insole materials [Astroshock, Plastazote, Poron, Professional Protec- tive Technology, Evazote, Noene] were tested. The force/strain curves were recorded at various cycles up to 50,000 cycles of compression. This approx- imately equates to 12 hours of continuous walking or 12 weeks of walking in a normal person. The compliance of the material was assessed by measuring the gradient of the curve. By measuring the area underneath the force/strain curve, the amount of shock absorbed by the insole material was calculated. Astroshock was shown to be the best shock absorbing insole and Evazote the least. Poron was the least rigid material. Plastazote and Evazote were the most rigid materials up to 10,000 cycles; Noene was the most rigid material at the end of 50,000 cycles (excluding Plastazote and Evazote). All the materials tested showed deterioration of shock absorbency and com- pliancy with repeated compressions, with marked variations in between. Ac- celerated degradation of properties was found in the first 5000 cycles of compression, with more gradual deterioration thereafter. The compliance of the insoles was not uniform throughout the loading cycle. Insoles were more compliant in the early phase of the loading cycle and more rigid in the latter part. Astroshock was found to be the most promising shock absorbing insole, even after 50,000 cycles of compression. Evazote was the least shock absorbing material amongst all tested. Poron was the least rigid material. 4767 Mo-Tu, no. 51 (P61) The evaluation of the impact-absorption properties of rubber tiles for the playground L.-T. Changa, T.-J. Huangb. 1Department of Childhood Education and Nursery, Chia Nan University of Pharmacy and Science, Tainan, Taiwan, 2Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan Rubber tiles are popular in playgrounds as protective surfacing to reduce the incidence of head injuries caused by children falling from equipment. However, Taiwan has not yet established a test code for assessment of the shock-absorption properties of such surfacing. For this study, an experimental model was established to evaluate the behavior of various rubber tiles. A hemispherical headform was dropped from a set height to strike the center of the specimen tile. The peak acceleration and Head Injury Criterion (HIC) were measured to assess the impact absorption of and critical height for a given rubber tile. The results show that utilization of the HIC index provides a more conservative assessment of the shock absorption and, ultimately, protection from head injuries than peak acceleration. The maximum critical heights of the rubber tiles used in this study for tile thicknesses of 45, 60 and 80 mm were 1.6, 2.0 and 2.2 m, respectively. Two-part rubber tiles with a base structure consisting of a box-like core offer superior protection from head injuries relative to analogous cylindrical, square pillar and solid structures. The maximum differences in peak-acceleration and HIC values comparing the box-like core and solid structures at a thickness of 45 mm were 21% and 44%, respectively. The results of this study suggest a minimum of rubber thickness of 60 mm, based on probable maximum fall heights of more than 1.6 m. Moreover, incorporation of an appropriate cushioning structure in the base of the rubber tile could further improve protection.
Transcript of The new design of movable target dummy device for taekwondo
$554 Journal of Biomechanics 2006, Vol. 39 (Suppl 1) Poster Presentations
validated by means of mechanical tests on physical prototypes produced on purpose.
7697 Mo-Tu, no. 47 (P61) The study of a new designed table tennis racket for training strike accuracy C.-'~ Peng, J.-L. Chen, T.-'~ Shiang. Taipei Physical Education College, Taipei, Taiwan
The major movement of table tennis is striking the ball on racket to create high rebound speed. Sweet spot striking can create high rebound speed and easier control the ball as well as increase spin of the ball. But beginners can not know where on the racket they strike the ball even they can play the game well. In order to train the beginners to strike the ball in sweet spot and distinguish the impact accuracy, a new table tennis racket was designed using a common blade with two parts on the racket face. The sweet spot area remained normal material and surrounding area used cushioning material to absorb the impact energy to reduce the rebound speed. The character of the new racket design was when the ball strikes on the sweet spot, the ball can across the net. When the ball doesn't strike on the sweet spot, the ball can't across the net. A subject was asked to strike 90 balls for both forehand and backhand using this new racket. Results showed that the successful rate of sweet spot striking could reach almost 95%, the successful rate of non sweet spot striking could only reach 4%. Especially when using backhand strike in the non sweet spot, the successful rate could reach only 2%. As a conclusion that the new design training racket can effectively provide the feedback message for users. And the rackets can be used for training beginner or test the strike accuracy of player.
4741 Mo-Tu, no. 48 (P61) The new design of movable target dummy device for taekwondo
C.-J. Lee 1, W.-H. Ho 2, A.-B. Chen 3. 1Institute of Sports Equipment Technology, Taipei Physical Education College, Taipei, Taiwan, 2Institute of Sports Technique, Taipei Physical Education College, Taipei, Taiwan, 3Department of Technique Sports Science, Taipei Physical Education College, Taipei, Taiwan.
The traditional Tae Kwon Do practicing device appears in the form of a fixed target dummy or a punching bag. However, both forms can not accurately react to active attacks or continuous passive attacks from a real opponent in a match. Accordingly, the research intends to develop a movable target dummy with motor-driven steel wires to simulate the forward or backward movement of an adversary. This fighting art device is adjustable in height to suit the different heights of athletes, and is equipped with force sensors that will collect team members' kicking force. This research divided 8 A-grade male Tae Kwon Do members into 2 groups - superior and general - for kick testing of the reciprocating action performances. At a speed of 2 m/s, while the other group kicked 7.2±0.69 and 5.47±2.29 number times. These testing results successfully meet our purpose in providing immediate feedback to coaches about athletes' performance. The research aims to develop a movable Tae Kwon Do target dummy that can replicate the fighting mode in contest, and to upgrade the present contest training machine in order to provide Tae Kwon Do players with effective training and evaluating equipment.
4838 Mo-Tu, no. 49 (P61) Development of a foot-to-foot impedancemeter for measuring body composition during exercise M.-V. Moreno 1 , H. Mehalebi 1 , G. Baquet 2, D. Thevenet 3, EX. Gamelin 2, S. Berthoin 2, M.'~ Jaffrin 1 . 1Dept of BioL Engineering, UMR-CNRS 6600, Tech. University of Compiegne, France, 2Laboratory of human motricity (EA n°3608), Dept. of sport science, University of Lille 2, France, 3Laboratory of Motricity, Interactions, Performance (JE n°2438), UFR STAPS of Nantes, France
Foot-to-foot impedancemeters (FFI) are cheaper, simpler and quicker to use than medical type impedancemeters. The purpose of this work was to increase the functions of a prototype FFI derived from a commercially available FFI (Tefal Bodymaster Vision,Rumilly, France)with performing electronics, in order to obtain extracellular (ECW), total body water (TBW) volumes, body cell mass (BCM) and muscle mass in addition to weight and fat-free mass. A modification of the FFI permitted also to use it with hand and feet reusable electrodes. ECW and TBW measurements with the FFI were achieved by comparison with measurements made using a multifrequency medical impedancemeter Hydra 4200 (Xitron Tech, San Diego) and Dual X ray absorptiometry and appropriate modifications of the bioimpedance spectroscopic (BIS) method (1, 2). For BCM and muscle mass, we used Kotler's and Wang's methods re- spectively to relate them to the total body potassium concentration TBK as BCM =0.0083TBK, Muscle mass =0 .0093TBK+0.024Age-3 .21 , where TBK
is expressed in terms of Xcp, the equivalent reactance at 50 kHz, the subject height H, and his weight W. These methods were applied on a group of 52 children: 12 controls did not practice exercise, 20 jogged intermittently and 20 jogged regularly for three months. Changes in all the physiologic parameters listed above during this period as well as improvement in running speed for the three groups were compared and will be reported. With further development, this FFI prototype, which is easy to use and has indefinitely reusable electrodes, can be particularly useful in training and sport centers.
References [1] Jaffrin MY, Kieffer R., Moreno M-V. Nutrition 2005; 21: 815424. [2] Fenech M, Jaffrin MY, Dabaja Z. Arch. Phys. Biochem. 2003; 111 : 20.
5216 Mo-Tu, no. 50 (P61) How long do insoles last: a simulation study? C. Birudavolu, G. Arnold, T. Drew, R. Abboud. Institute of Motion Analysis & Research (IMAR), University of Dundee, Scotland, UK
Shock absorbing insoles have proved to be effective in the treatment of various foot pathologies. Many studies in the past have evaluated the efficacy of insoles with considerable discrepancy in their outcomes with most conducted using new insoles. Very few studies looked at the long-term performance of insoles after prolonged usage. This study aimed to assess the mechanical properties of commonly used insole materials under normal simulated use. The objectives were to investigate the rigidity/compliancy and shock absorbency of each material over a period of 50,000 cycles of repeated compressions using a Universal Testing Machine. Six insole materials [Astroshock, Plastazote, Poron, Professional Protec- tive Technology, Evazote, Noene] were tested. The force/strain curves were recorded at various cycles up to 50,000 cycles of compression. This approx- imately equates to 12 hours of continuous walking or 12 weeks of walking in a normal person. The compliance of the material was assessed by measuring the gradient of the curve. By measuring the area underneath the force/strain curve, the amount of shock absorbed by the insole material was calculated. Astroshock was shown to be the best shock absorbing insole and Evazote the least. Poron was the least rigid material. Plastazote and Evazote were the most rigid materials up to 10,000 cycles; Noene was the most rigid material at the end of 50,000 cycles (excluding Plastazote and Evazote). All the materials tested showed deterioration of shock absorbency and com- pliancy with repeated compressions, with marked variations in between. Ac- celerated degradation of properties was found in the first 5000 cycles of compression, with more gradual deterioration thereafter. The compliance of the insoles was not uniform throughout the loading cycle. Insoles were more compliant in the early phase of the loading cycle and more rigid in the latter part. Astroshock was found to be the most promising shock absorbing insole, even after 50,000 cycles of compression. Evazote was the least shock absorbing material amongst all tested. Poron was the least rigid material.
4767 Mo-Tu, no. 51 (P61) The evaluation of the impact-absorption properties of rubber tiles for the playground
L.-T. Changa, T.-J. Huangb. 1Department of Childhood Education and Nursery, Chia Nan University of Pharmacy and Science, Tainan, Taiwan, 2Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan
Rubber tiles are popular in playgrounds as protective surfacing to reduce the incidence of head injuries caused by children falling from equipment. However, Taiwan has not yet established a test code for assessment of the shock-absorption properties of such surfacing. For this study, an experimental model was established to evaluate the behavior of various rubber tiles. A hemispherical headform was dropped from a set height to strike the center of the specimen tile. The peak acceleration and Head Injury Criterion (HIC) were measured to assess the impact absorption of and critical height for a given rubber tile. The results show that utilization of the HIC index provides a more conservative assessment of the shock absorption and, ultimately, protection from head injuries than peak acceleration. The maximum critical heights of the rubber tiles used in this study for tile thicknesses of 45, 60 and 80 mm were 1.6, 2.0 and 2.2 m, respectively. Two-part rubber tiles with a base structure consisting of a box-like core offer superior protection from head injuries relative to analogous cylindrical, square pillar and solid structures. The maximum differences in peak-acceleration and HIC values comparing the box-like core and solid structures at a thickness of 45 mm were 21% and 44%, respectively. The results of this study suggest a minimum of rubber thickness of 60 mm, based on probable maximum fall heights of more than 1.6 m. Moreover, incorporation of an appropriate cushioning structure in the base of the rubber tile could further improve protection.
