The preceding parts of the review concerned kinanthropometric parameters, skeletal muscle recruitment, ergometry, systemic responses and adaptations. Main teachings of this third part of the whole review follow. At th...The preceding parts of the review concerned kinanthropometric parameters, skeletal muscle recruitment, ergometry, systemic responses and adaptations. Main teachings of this third part of the whole review follow. At the 1996 Atlanta Olympic Game, most vitamin users (91 percent) were boxers. After 18 days of endurance training at the altitude of 1800 m, in boxers, 1) erythropoietin and reticulocytes values increased, 2) remained unchanged parameters of iron metabolism and maximal oxygen uptake values, 3) iron supplementation decreased total body hemoglobin values. Zinc supplementation and/or regularity while boxing influenced plasma levels of calcium, copper, iron, magnesium, phosphorus and zinc in boxers. Sodium bicarbonate ingestion increased punches frequency and time to fatigue in boxers. Boxing-induced thermal dehydration yielded 1) body and muscle masses decrease compensated by increased neural input to muscle, to maintain muscle strength, but 2) a 26.8 percent performance fall. In boxers, fluid and food intake restriction 1) changed neither blood vitamin status nor plasma glutathione levels, 2) yielded a) a negative mood profile and a performance decrease, when resulted in body mass fall by 5.16 percent but b) no performance decrease when fall was by three percent. Diet protein or protein and caloric components decrease increased, in boxers, protein catabolism and, for the same submaximal workload, heart rate and oxygen intake. In food-restricted boxers, myoprotein catabolism increased with decreasing meal intake frequency. Competition and no-competition boxers utilize massage. Massage increased perceptions of recovery after a whole boxing performance. High level of cardiorespiratory fitness accelerates recovery process between boxing rounds.展开更多
To improve the quality of boxing teaching in competitive sports schools,it is necessary to first analyze the strengths and weaknesses of boxing teaching in competitive sports schools,and then optimize the teaching str...To improve the quality of boxing teaching in competitive sports schools,it is necessary to first analyze the strengths and weaknesses of boxing teaching in competitive sports schools,and then optimize the teaching strategy.The strategies include innovating the boxing curriculum system and content,building learning communities inside and outside the classroom,personalizing the teaching forms and methods,using multimedia to broaden the teaching path,focusing on the integration of boxing teaching leagues,and diversifying the teaching incentives and evaluations.展开更多
High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the ex...High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.展开更多
Two prototype pneumatic boxing gloves of different design were compared against conventional 10?oz (Std 10?oz) and 16?oz (Std 16?oz) gloves in terms of ability to reduce impact forces delivered to a target. One of the...Two prototype pneumatic boxing gloves of different design were compared against conventional 10?oz (Std 10?oz) and 16?oz (Std 16?oz) gloves in terms of ability to reduce impact forces delivered to a target. One of the pneumatic gloves (SBLI) contained a sealed air bladder inflated to a pressure of 2?kPa. The other (ARLI) incorporated a bladder that allowed release of air to the external environment upon contact with a target, followed by rapid air reuptake. Each glove was placed on to a mechanical fist and dropped 10 times on to an in-floor force plate from each of nine heights ranging from 1.0 to 5.0 metres, with the 5-metre drop generating a peak pre-impact glove velocity close to the reported maximum for elite boxers. Compared to the conventional gloves, the ARLI glove substantially reduced peak impact forces at all drop heights, with the reduction exceeding 30% even at the 5-metre level. The SBLI glove was as effective as the ARLI glove in reducing peak impact forces at drop heights of up to 2.5 metres, but its performance then progressively diminished, and at drop heights of 4.0, 4.5 and 5.0 metres it produced peak force readings similar to those recorded for the Std 10?oz and Std 16?oz gloves. The superiority of the ARLI glove was even more evident in relation to peak rate of force development, with reductions relative to the Std 10?oz glove being ~60% at drop heights up to 3.5 metres and still ~47% at 5 metres. Peak rate of force development for the SBLI glove exceeded that for the ARLI glove for all drop heights of 2.0 metres and above, and at 4.0, 4.5 and 5.0 metres it was higher than the readings for the Std 10 oz and 16?oz gloves. The protective effect of the ARLI glove was?associated with an increase in impact compliance and prolongation of contact time between glove and target. It is concluded that a pneumatic boxing glove that provides for air exchange with the external environment can greatly reduce impact magnitudes across the whole range of pre-impact glove velocities likely to be encountered in boxing, thereby mitigating risks associated with the sport. While acceptance of the gloves by the boxing community is uncertain, opportunity may exist for almost immediate uptake in modified boxing programs.展开更多
The Boxing Sag is located in the southwest of Dongying Depression, southern Bohai Bay Basin of East China. It is one of the main petroliferous sags in the Dongying Depression, and has two major source rocks, namely th...The Boxing Sag is located in the southwest of Dongying Depression, southern Bohai Bay Basin of East China. It is one of the main petroliferous sags in the Dongying Depression, and has two major source rocks, namely the upper 4th Member (Es4u) and lower 3rd Member (Es31) shales of Eocene Shahejie Formation, which are the new exploration targets in recent years. In this study, 16 core samples were collected from Es4u and Es31 shales in the Boxing Sag, and the saturate hydrocarbons were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), respectively. The results show that Es4u shale has obvious phytane and gammacerane predominance, higher concentration of tricyclic terpanes and regular steranes, and very low concentration of 4- methly steranes; Es31 shale has pristane predominance, lower concentration of tricyclic terpanes, gammacerane and regular steranes, and higher concentration of 4-methly steranes. The Es4u shale can be further divided into two types based on the distribution of n-alkanes in gas chromatograms: normal distribution and double peak pattern. The biomarker characteristics and sedimentary facies distribution show that Es4u shale was deposited in the saline-hypersaline semi-deep (Type A Es4u shale, sag center) to shallow (Type B Es4u shale, sag edge) lacustrine environments, Es31 shale was deposited in the freshwater-brackish semi-deep-deep lacustrine environments, and the former sedimentary facies maps of Es4u and Es31 in the Boxing Sag are further modified.展开更多
A conventional boxing glove and a prototype pneumatic glove were each fitted to a mechanical fist and dropped 253 times from a height of 3 metres on to a force plate covered by an ethylene vinyl acetate (EVA) mat. Imp...A conventional boxing glove and a prototype pneumatic glove were each fitted to a mechanical fist and dropped 253 times from a height of 3 metres on to a force plate covered by an ethylene vinyl acetate (EVA) mat. Impact dynamics were measured and modelled. From the outset, peak impact force and peak rate of force development (loading rate) were lower for the pneumatic glove. For both gloves, these variables displayed upward drift during the drop series, but the drift was smaller for the pneumatic glove. Consequently, the magnitude of the protective effect provided by the pneumatic glove increased with the number of impacts. For the conventional glove, change in peak force showed a close inverse relationship to force plate contact time (R2?>?0.96) and the time from first contact of the glove with the force plate to attainment of peak force (R2?=?0.85). These relationships were much weaker for the pneumatic glove (R2?=?0.09 and 0.59 respectively), suggesting the possibility of a more complex impact damping mechanism. Following the 253 drops of the pneumatic glove, the EVA mat covering the force plate was replaced, and another 10 drops then performed. Peak force readings were immediately reduced to an extent suggesting that 26%?-?34% of the increase that had occurred over the 253 drops was attributable to impact-induced change in mat properties. This has implications for future experimental designs. Overall, the findings provided further evidence of the potential of pneumatic gloves to enable safer boxing.展开更多
The impact damping capabilities of four different boxing gloves were assessed under two different conditions of target padding to determine whether target characteristics might influence previous conclusions concernin...The impact damping capabilities of four different boxing gloves were assessed under two different conditions of target padding to determine whether target characteristics might influence previous conclusions concerning potential for impact mitigation through novel glove design. A conventional 10?oz glove (Std 10?oz), a conventional 16?oz glove (Std 16?oz), a prototype pneumatic glove with a sealed bladder (SBLI) and a prototype pneumatic glove with a bladder allowing air exchange with the external environment (ARLI) were each dropped three times on to a force plate from six heights ranging from 2.5 to 5.0 metres. The force plate was covered by a 50 mm thick mat of EVA material and results obtained were compared with those of an earlier experiment involving use of a similar protocol but a 25 mm thick EVA force plate covering. The thicker mat greatly reduced peak impact forces for all gloves, with values for the Std 10?oz glove becoming much closer to those reported by other researchers for punches delivered by elite boxers to crash test manikins. Peak rates of force development were also substantially decreased. Protective effects provided by the ARLI glove relative to the Std 10?oz glove were diminished but still in the order of 17%?-?22% for peak impact force and 27%?-?49% for peak rate of force development across the range of drop heights. With the 50 mm mat thickness, the SBLI glove was as effective as the ARLI glove in reducing peak impact force, whereas this was not the case with the 25 mm mat. It was, however, always inferior to the ARLI glove in decreasing peak rate of force development. The ability of the ARLI glove to afford protection across a spectrum of impact conditions could yield important practical advantages.展开更多
This study was aimed at improved understanding of the mechanisms of previously reported protective effects of a pneumatic boxing glove. A Motion Capture System was used to obtain velocity data from four different boxi...This study was aimed at improved understanding of the mechanisms of previously reported protective effects of a pneumatic boxing glove. A Motion Capture System was used to obtain velocity data from four different boxing gloves dropped on to a force plate from nine heights ranging from 1 to 5 metres. Two gloves were of the conventional type but differed in mass. The other two were prototype pneumatic gloves. One of these (SBLI) had a sealed bladder while the other (ARLI) incorporated a port allowing air exchange with the external environment. The pneumatic gloves decelerated more slowly than the conventional gloves following impact and compressed through a greater absolute distance. Consequently, they took longer to reach zero velocity. As drop height increased, these trends became more pronounced for the ARLI glove than the SBLI glove. Increase in velocity during rebound was also slower for the pneumatic gloves. The ARLI glove had a lower coefficient of restitution than any of the other gloves at low to moderate drop heights but not at high drop heights. The SBLI glove had a higher coefficient of restitution than the other gloves at all drop heights from 2 metres upwards. This indicated that, overall, the ARLI glove was the most effective, and the SBLI glove the least effective, in dissipating the kinetic energy of impact through conversion to other energy forms. For all gloves at all drop heights, peak positive acceleration at the beginning of rebound was of lower absolute magnitude than peak negative acceleration at the end of compression. The influence of drop height on an index characterising this relationship differed between the conventional and pneumatic gloves, possibly reflecting structural changes to gloves as impact energy increased. The conventional and pneumatic gloves differed regarding temporal alignment between key kinematic and kinetic events, and there were some differences between the two pneumatic gloves in this respect. Nevertheless, peak glove deceleration correlated highly with peak impact force, not only for each glove individually but also when data for all gloves were combined. The findings confirmed the potential practical utility of the ARLI glove and identified air cushion thickness, glove compressibility and capacity for air release and subsequent reuptake as critical aspects of its design.展开更多
Seven percent voluntary body weight decrease by boxers requires 21 days while 4.4 percent increase needs only one day. Energy and fluid intakes reduction does not affect boxers punching force. Boxers effective punch m...Seven percent voluntary body weight decrease by boxers requires 21 days while 4.4 percent increase needs only one day. Energy and fluid intakes reduction does not affect boxers punching force. Boxers effective punch masses and body weights correlate. Wrist girths and competition rankings of boxers correlate. Boxers show leanness body fat percentage. Boxers, generally highly mesomorphic, with increasing body weight, show ectomorphy decreases but endomorphy and mesomorphy increases. Vibration treatment enhances power in boxers arm flexors. Presence, nature and thickness of bandages and gloves donned influence boxers punch force. Stance posture adopted by boxers ends in locomotion functional parameters adaptations. Muscular recruitment sequence during rear straight punches may be influenced by the target height (head or body levels) and the boxer intention (produce maximal force or maximal speed). Handgrip strength: 1) increases from younger to older and from lighter to heavier boxers, and 2) correlates with competition ranking. Rear knee extension increases rear straight punching force to the head. Compared to uppercut and straight punches, the hook produces the highest change in hand velocity. Maximal forces are larger for the rear than the lead hand, and greater in more than in less experienced boxers. Hook punch force is greater than those of uppercut and straight punches. Boxer aim (produce maximum force or maximum speed) influence his punching force. Massage neither prevents a decrement in repeated performance nor has detrimental effects on performance, but increases recovery perceptions, compared with the passive rest intervention.展开更多
The present journal paper is the second of the three parts of a whole boxing practitioners physiology review. It is related to the boxing practice-derived systemic responses and adaptations. The first part of the revi...The present journal paper is the second of the three parts of a whole boxing practitioners physiology review. It is related to the boxing practice-derived systemic responses and adaptations. The first part of the review has dealt with kinanthropometric parameters, skeletal muscle recruitment and ergometry. The following and third part of the review is going to deal with dietary supplementation, weight control, recovery, altitude, faith, life expectancy, gender and childhood. Search engines and printed documents have helped gather the information that have been commented in the present and second part: responses and/or adaptations relating to 1) metabolism, 2) skeleton, 3) nervous system, 4) endocrine system, 5) cardiovascular system, 6) urinary tract and 7) pulmonary system. Detailed titles and subtitles of this part of the review are found at the end of the journal paper introduction. The main teachings from the present journal paper may be acquired through the consultation of the tables and figures that are positioned in the text, not forgetting the reminders and advice(s) that appear at the end of each of the seven parts of the journal paper (2.1.6., 2.2.2., 2.3.2., 2.4.2., 2.5.4, 2.6.4. and 2.7.3.).展开更多
文摘The preceding parts of the review concerned kinanthropometric parameters, skeletal muscle recruitment, ergometry, systemic responses and adaptations. Main teachings of this third part of the whole review follow. At the 1996 Atlanta Olympic Game, most vitamin users (91 percent) were boxers. After 18 days of endurance training at the altitude of 1800 m, in boxers, 1) erythropoietin and reticulocytes values increased, 2) remained unchanged parameters of iron metabolism and maximal oxygen uptake values, 3) iron supplementation decreased total body hemoglobin values. Zinc supplementation and/or regularity while boxing influenced plasma levels of calcium, copper, iron, magnesium, phosphorus and zinc in boxers. Sodium bicarbonate ingestion increased punches frequency and time to fatigue in boxers. Boxing-induced thermal dehydration yielded 1) body and muscle masses decrease compensated by increased neural input to muscle, to maintain muscle strength, but 2) a 26.8 percent performance fall. In boxers, fluid and food intake restriction 1) changed neither blood vitamin status nor plasma glutathione levels, 2) yielded a) a negative mood profile and a performance decrease, when resulted in body mass fall by 5.16 percent but b) no performance decrease when fall was by three percent. Diet protein or protein and caloric components decrease increased, in boxers, protein catabolism and, for the same submaximal workload, heart rate and oxygen intake. In food-restricted boxers, myoprotein catabolism increased with decreasing meal intake frequency. Competition and no-competition boxers utilize massage. Massage increased perceptions of recovery after a whole boxing performance. High level of cardiorespiratory fitness accelerates recovery process between boxing rounds.
文摘To improve the quality of boxing teaching in competitive sports schools,it is necessary to first analyze the strengths and weaknesses of boxing teaching in competitive sports schools,and then optimize the teaching strategy.The strategies include innovating the boxing curriculum system and content,building learning communities inside and outside the classroom,personalizing the teaching forms and methods,using multimedia to broaden the teaching path,focusing on the integration of boxing teaching leagues,and diversifying the teaching incentives and evaluations.
基金supported by a grant of the M.D.-Ph.D./Medical Scientist Training Program through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(to HK)+3 种基金supported by National Research Foundation of Korea(NRF)grants funded by the Korean government(MSITMinistry of Science and ICT)(NRF2019R1A5A2026045 and NRF-2021R1F1A1061819)a grant from the Korean Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea(HR21C1003)New Faculty Research Fund of Ajou University School of Medicine(to JYC)。
文摘High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.
文摘Two prototype pneumatic boxing gloves of different design were compared against conventional 10?oz (Std 10?oz) and 16?oz (Std 16?oz) gloves in terms of ability to reduce impact forces delivered to a target. One of the pneumatic gloves (SBLI) contained a sealed air bladder inflated to a pressure of 2?kPa. The other (ARLI) incorporated a bladder that allowed release of air to the external environment upon contact with a target, followed by rapid air reuptake. Each glove was placed on to a mechanical fist and dropped 10 times on to an in-floor force plate from each of nine heights ranging from 1.0 to 5.0 metres, with the 5-metre drop generating a peak pre-impact glove velocity close to the reported maximum for elite boxers. Compared to the conventional gloves, the ARLI glove substantially reduced peak impact forces at all drop heights, with the reduction exceeding 30% even at the 5-metre level. The SBLI glove was as effective as the ARLI glove in reducing peak impact forces at drop heights of up to 2.5 metres, but its performance then progressively diminished, and at drop heights of 4.0, 4.5 and 5.0 metres it produced peak force readings similar to those recorded for the Std 10?oz and Std 16?oz gloves. The superiority of the ARLI glove was even more evident in relation to peak rate of force development, with reductions relative to the Std 10?oz glove being ~60% at drop heights up to 3.5 metres and still ~47% at 5 metres. Peak rate of force development for the SBLI glove exceeded that for the ARLI glove for all drop heights of 2.0 metres and above, and at 4.0, 4.5 and 5.0 metres it was higher than the readings for the Std 10 oz and 16?oz gloves. The protective effect of the ARLI glove was?associated with an increase in impact compliance and prolongation of contact time between glove and target. It is concluded that a pneumatic boxing glove that provides for air exchange with the external environment can greatly reduce impact magnitudes across the whole range of pre-impact glove velocities likely to be encountered in boxing, thereby mitigating risks associated with the sport. While acceptance of the gloves by the boxing community is uncertain, opportunity may exist for almost immediate uptake in modified boxing programs.
基金financially supported by the Research Institute of Geological Science of Shengli Oilfield Company Limited and by the State Key Laboratory of Petroleum Resources and Prospecting (No. prp2009-02)
文摘The Boxing Sag is located in the southwest of Dongying Depression, southern Bohai Bay Basin of East China. It is one of the main petroliferous sags in the Dongying Depression, and has two major source rocks, namely the upper 4th Member (Es4u) and lower 3rd Member (Es31) shales of Eocene Shahejie Formation, which are the new exploration targets in recent years. In this study, 16 core samples were collected from Es4u and Es31 shales in the Boxing Sag, and the saturate hydrocarbons were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), respectively. The results show that Es4u shale has obvious phytane and gammacerane predominance, higher concentration of tricyclic terpanes and regular steranes, and very low concentration of 4- methly steranes; Es31 shale has pristane predominance, lower concentration of tricyclic terpanes, gammacerane and regular steranes, and higher concentration of 4-methly steranes. The Es4u shale can be further divided into two types based on the distribution of n-alkanes in gas chromatograms: normal distribution and double peak pattern. The biomarker characteristics and sedimentary facies distribution show that Es4u shale was deposited in the saline-hypersaline semi-deep (Type A Es4u shale, sag center) to shallow (Type B Es4u shale, sag edge) lacustrine environments, Es31 shale was deposited in the freshwater-brackish semi-deep-deep lacustrine environments, and the former sedimentary facies maps of Es4u and Es31 in the Boxing Sag are further modified.
文摘A conventional boxing glove and a prototype pneumatic glove were each fitted to a mechanical fist and dropped 253 times from a height of 3 metres on to a force plate covered by an ethylene vinyl acetate (EVA) mat. Impact dynamics were measured and modelled. From the outset, peak impact force and peak rate of force development (loading rate) were lower for the pneumatic glove. For both gloves, these variables displayed upward drift during the drop series, but the drift was smaller for the pneumatic glove. Consequently, the magnitude of the protective effect provided by the pneumatic glove increased with the number of impacts. For the conventional glove, change in peak force showed a close inverse relationship to force plate contact time (R2?>?0.96) and the time from first contact of the glove with the force plate to attainment of peak force (R2?=?0.85). These relationships were much weaker for the pneumatic glove (R2?=?0.09 and 0.59 respectively), suggesting the possibility of a more complex impact damping mechanism. Following the 253 drops of the pneumatic glove, the EVA mat covering the force plate was replaced, and another 10 drops then performed. Peak force readings were immediately reduced to an extent suggesting that 26%?-?34% of the increase that had occurred over the 253 drops was attributable to impact-induced change in mat properties. This has implications for future experimental designs. Overall, the findings provided further evidence of the potential of pneumatic gloves to enable safer boxing.
文摘The impact damping capabilities of four different boxing gloves were assessed under two different conditions of target padding to determine whether target characteristics might influence previous conclusions concerning potential for impact mitigation through novel glove design. A conventional 10?oz glove (Std 10?oz), a conventional 16?oz glove (Std 16?oz), a prototype pneumatic glove with a sealed bladder (SBLI) and a prototype pneumatic glove with a bladder allowing air exchange with the external environment (ARLI) were each dropped three times on to a force plate from six heights ranging from 2.5 to 5.0 metres. The force plate was covered by a 50 mm thick mat of EVA material and results obtained were compared with those of an earlier experiment involving use of a similar protocol but a 25 mm thick EVA force plate covering. The thicker mat greatly reduced peak impact forces for all gloves, with values for the Std 10?oz glove becoming much closer to those reported by other researchers for punches delivered by elite boxers to crash test manikins. Peak rates of force development were also substantially decreased. Protective effects provided by the ARLI glove relative to the Std 10?oz glove were diminished but still in the order of 17%?-?22% for peak impact force and 27%?-?49% for peak rate of force development across the range of drop heights. With the 50 mm mat thickness, the SBLI glove was as effective as the ARLI glove in reducing peak impact force, whereas this was not the case with the 25 mm mat. It was, however, always inferior to the ARLI glove in decreasing peak rate of force development. The ability of the ARLI glove to afford protection across a spectrum of impact conditions could yield important practical advantages.
文摘This study was aimed at improved understanding of the mechanisms of previously reported protective effects of a pneumatic boxing glove. A Motion Capture System was used to obtain velocity data from four different boxing gloves dropped on to a force plate from nine heights ranging from 1 to 5 metres. Two gloves were of the conventional type but differed in mass. The other two were prototype pneumatic gloves. One of these (SBLI) had a sealed bladder while the other (ARLI) incorporated a port allowing air exchange with the external environment. The pneumatic gloves decelerated more slowly than the conventional gloves following impact and compressed through a greater absolute distance. Consequently, they took longer to reach zero velocity. As drop height increased, these trends became more pronounced for the ARLI glove than the SBLI glove. Increase in velocity during rebound was also slower for the pneumatic gloves. The ARLI glove had a lower coefficient of restitution than any of the other gloves at low to moderate drop heights but not at high drop heights. The SBLI glove had a higher coefficient of restitution than the other gloves at all drop heights from 2 metres upwards. This indicated that, overall, the ARLI glove was the most effective, and the SBLI glove the least effective, in dissipating the kinetic energy of impact through conversion to other energy forms. For all gloves at all drop heights, peak positive acceleration at the beginning of rebound was of lower absolute magnitude than peak negative acceleration at the end of compression. The influence of drop height on an index characterising this relationship differed between the conventional and pneumatic gloves, possibly reflecting structural changes to gloves as impact energy increased. The conventional and pneumatic gloves differed regarding temporal alignment between key kinematic and kinetic events, and there were some differences between the two pneumatic gloves in this respect. Nevertheless, peak glove deceleration correlated highly with peak impact force, not only for each glove individually but also when data for all gloves were combined. The findings confirmed the potential practical utility of the ARLI glove and identified air cushion thickness, glove compressibility and capacity for air release and subsequent reuptake as critical aspects of its design.
文摘Seven percent voluntary body weight decrease by boxers requires 21 days while 4.4 percent increase needs only one day. Energy and fluid intakes reduction does not affect boxers punching force. Boxers effective punch masses and body weights correlate. Wrist girths and competition rankings of boxers correlate. Boxers show leanness body fat percentage. Boxers, generally highly mesomorphic, with increasing body weight, show ectomorphy decreases but endomorphy and mesomorphy increases. Vibration treatment enhances power in boxers arm flexors. Presence, nature and thickness of bandages and gloves donned influence boxers punch force. Stance posture adopted by boxers ends in locomotion functional parameters adaptations. Muscular recruitment sequence during rear straight punches may be influenced by the target height (head or body levels) and the boxer intention (produce maximal force or maximal speed). Handgrip strength: 1) increases from younger to older and from lighter to heavier boxers, and 2) correlates with competition ranking. Rear knee extension increases rear straight punching force to the head. Compared to uppercut and straight punches, the hook produces the highest change in hand velocity. Maximal forces are larger for the rear than the lead hand, and greater in more than in less experienced boxers. Hook punch force is greater than those of uppercut and straight punches. Boxer aim (produce maximum force or maximum speed) influence his punching force. Massage neither prevents a decrement in repeated performance nor has detrimental effects on performance, but increases recovery perceptions, compared with the passive rest intervention.
文摘The present journal paper is the second of the three parts of a whole boxing practitioners physiology review. It is related to the boxing practice-derived systemic responses and adaptations. The first part of the review has dealt with kinanthropometric parameters, skeletal muscle recruitment and ergometry. The following and third part of the review is going to deal with dietary supplementation, weight control, recovery, altitude, faith, life expectancy, gender and childhood. Search engines and printed documents have helped gather the information that have been commented in the present and second part: responses and/or adaptations relating to 1) metabolism, 2) skeleton, 3) nervous system, 4) endocrine system, 5) cardiovascular system, 6) urinary tract and 7) pulmonary system. Detailed titles and subtitles of this part of the review are found at the end of the journal paper introduction. The main teachings from the present journal paper may be acquired through the consultation of the tables and figures that are positioned in the text, not forgetting the reminders and advice(s) that appear at the end of each of the seven parts of the journal paper (2.1.6., 2.2.2., 2.3.2., 2.4.2., 2.5.4, 2.6.4. and 2.7.3.).