Cardiopulmonary loading in motocross riding

Abstract

The present study was designed to examine physiological responses during motocross riding. Nine Finnish A-level motocross riders performed a 15-min ride at a motocross track and a test of maximal oxygen uptake ([Vdot]O_2max) in the laboratory. Cardiopulmonary strain was measured continuously during the ride as well as in the [Vdot]O_2max test. During the ride, mean [Vdot]O₂ was 32 ml · kg^?1 · min^?1 (s = 4), which was 71% (s = 12) of maximum, while ventilation (V _E) was 73% (s = 15) of its maximum. The relative [Vdot]O₂ and V _E values during the riding correlated with successful riding performance (r = 0.80, P < 0.01 and r = 0.79, P < 0.01, respectively). Mean heart rate was maintained at 95% (s = 7) of its maximum. Mean blood lactate concentration was 5.0 mmol · l^?1 (s = 2.0) after the ride. A reduction of 16% (P < 0.001) in maximal isometric handgrip force was observed. In conclusion, motocross causes riders great physical stress. Both aerobic and anaerobic metabolism is required for the isometric and dynamic muscle actions experienced during a ride.     

Dynamic pressure effect on horse and horse rider during riding

Horse riding predisposes to degenerative spinal injury to both rider and horse. This study evaluated the dynamic pressure exerted on horse and horse rider. The main comparison investigated was how the flocking (cushioning) material of a saddle affected the pressure exerted on both. Six horse riders and one horse were used to conduct this study. The Pliance^® horse saddle and seat pressure testing systems, designed by Novel_GmBH, were used for this study. Pressure recordings were carried out from a saddle fitted with wool then again following its conversion to air flocking. Both flocking materials were tested during a variety of different gait settings using two pressure mats to record the pressures firstly being exerted onto the horse and secondly onto the rider. This study was the first carried out to examine the pressure exerted on horse and rider. Results found that both the mean peak pressure (MPP) and mean pressure–time integral (PTI) exerted on the rider increased by as much as 21.9 and 22 %, respectively, following conversion to air flocking. In contrast, the air flocking saddle exerted a lower MPP and PTI on the horse by as much as 25.3 and 26.6 %, respectively. This study has shown that air flocking reduces the pressure exerted on the horse; however, it has also indicated that it increased the pressures exerted on the rider. As a result of our study, further research needs to be conducted to determine the most appropriate material to flock a saddle with.     

Investigation of snowboard stiffness and camber characteristics for different riding styles

Previous research has indicated that the flex pattern and camber of a snowboard are crucial to its perceived “feel”, or the physical and psychological feedback given to the rider whilst snowboarding. These features are the primary cause of variation in snowboard performance for different riding styles. Consequently, this article deals with the identification of stiffness and camber characteristics for freestyle, freeride and versatile test boards, and their statistical correlation to a comprehensive list of qualitative feel-based performance requirements. It has been determined that the test boards spanning the major styles all possessed similar bending profiles, that were highly representative of each snowboard’s respective thickness distribution. The torsional stiffness curves however appeared to be driven by the composite architecture used in construction. Unsurprisingly, the freeride test board showed the greatest level of overall stiffness. The versatile board exhibited the greatest fluctuation in bending stiffness along the chord, whereas the freestyle profile was far more even throughout, with less variation from tip to tail. All of the subjective performance parameters except forgiveness showed positive associations to the body stiffness and camber, with manoeuvrability exhibiting the strongest correlations. The forgiveness showed the exact opposite trend, implying that higher levels of flex and less camber promotes a forgiving snowboard.     

The Swedish riding school: a social arena for young riders

The aim was to explore how young riders experience the riding school. By analysing focus groups interviews, a picture emerged showing that young riders’ main motive for participating at riding schools was the social aspects. Riding schools could be characterized through an institutional perspective in which the young riders became internalized and socialized into a stable culture. The young riders identified with the norms and values of the riding instructors through master–apprentice learning. In addition, the results revealed a change in the stable culture since the instructors encouraged social interactions and participation in the community that became central to learning and development. Opportunities to influence and interact were important for the individuals and from a child’s rights perspective. Through participation in the community of practice at riding schools, young riders not only learn about riding and horse management but also develop important personal social skills.     

A Cardiopulmonary Instructor's Perspective on a Standardized Patient Experience: Implications for Cardiopulmonary Physical Therapy Education

Purpose: Standardized patients (SP) in Doctor of Physical Therapy (DPT) curricula are increasingly used for students to practice developing clinical reasoning, communication, and professional skills in an authentic learning environment. The purposes of this article are to: (1) describe an instructional model that synthesized SPs, Internet-based communities of practice, and reflection to teach clinical reasoning in DPT students; and (2) a cardiovascular and pulmonary physical therapy (CPPT) instructor''s perspective on the educational process and student clinical skill development. Summary of Key Points: The model, employed in a course: “Integrative Physical Therapy Practice,” enabled the instructor to document student clinical performance and reasoning during an SP interaction. For students, clinical reasoning was illuminated through the model''s assessment process. Data collected through the assessment process provided important feedback to the instructor on classroom instructional effectiveness. Conclusions: Examination of student learning experiences enabled the instructor to consider: (1) key aspects of examination and management for persons with cardiovascular or pulmonary disorders, (2) methods for visualizing clinical reasoning, (3) the impact of teaching on student learning, and (4) strategies for teaching CPPT. More research is indicated to investigate pedagogy for the development of clinical reasoning in DPT students.Key Words: standardized patient, clinical reasoning, reflection, physical therapy education, cardiovascular, pulmonary     

坡道骑行对发展短距离自行车运动员专项力量的效果

采用不同坡道结合齿轮比率的变化方式进行训练,提高短距离自行车运动员膝关节股四头肌与绳肌肌力的功能。用Cybex－600型等速测力系统对实验结果进行评定。结果表明：3个月的坡道骑行训练对受试者股四头肌和绳肌肌力在4种不同速度的测试中,PT和TW值均有显著提高。提高幅度随速度的增高呈上升趋,300°／s时提高最显著。坡道骑行是一种自然型负荷训练,能使运动员在专项训练的自然情况下有效提高专项力量的能力。     

女子赛艇运动员模拟比赛中心肺功能变化特点的研究

探讨女子赛艇运动员在不同比赛模式中心肺功能动态变化的特点。以北京赛艇队6名女子运动员为研究对象．了解在2000m模拟比赛中利用心肺功能仪研究运动员心肺功能指标的变化情况。结果表明2000m模拟比赛不仅需要运动员具备良好的有氧代谢能力，还需要具备较强的无氧糖酵解能力和耐酸能力；2000m模拟比赛过程中运动员基本处于酸中毒造成的过度通气状态．随着比赛的进行．肺的通气血流灌注逐渐出现轻微的失调；在2000m模拟比赛过程中．运动员分段速度安排的不同将引起CO2排出量的不同．第1、3、4个500m段落CO2排出量的波动也许是造成模拟比赛后血乳酸峰值差异的原因。     

少年中长跑运动员心肺功能特点的研究

通过心肺功能运动试验(CPET),对沈阳市48名少年中长跑运动员进行测试,分析其心肺功能的特点.测试结果显示:静息状态下高年龄组的最大通气能力、通气储备能力和心搏量比同性别低年龄组强;亚极量负荷运动时,高年龄组运动员的运动能力高于同性别低年龄组;极量运动负荷时,女子组高年龄段的心脏的工作效率明显高于低年龄组,但低年龄组有氧代谢能力有很大的挖掘潜力.旨在为少年运动员的训练和比赛提供科学的理论依据,也为教练员今后选材和制定合理的训练计划提供可参考的理论基础.     

CS-200运动心肺功能测试系统在机能评定中的应用

介绍CS-200运动心肺功能测试系统的使用方法及该系统在运动实践测试中的常用指标,认为该系统能有效监测训练进程,为教练员提供可靠的实验数据,为帮助受试者制定合理运动处方提供依据。     

探究运动干预对中年女性心肺耐力的影响

目的通过研究不同运动干预对40～49岁体力活动不足女性心肺耐力的影响,从不同指标揭示心肺耐力的适应变化情况,进而为心肺耐力的运动处方提供数据化的科学依据和参考。方法采用Shapiro-Wilk检验数据正态性,用Three-Way ANOVA进行交互作用和主效应分析。结果从最大摄氧量指标上看,在小量中强度组增加的具有显著性差异(p<0.05);并且在小量大强度组和大量中强度组增加的结果非常显著(p<0.01)。结论每周进行150min的小量中强度运动、 90min的小量大强度运动以及180min大量中强度均能促进体力活动不足中年女性的心肺耐力的提升,其中每周进行90min的小量大强度运动可能是引起心肺耐力提升的最小运动剂量,即强度的作用更大一些,及增大强度后可以缩短运动时间,以达到健康效果。     

Biomechanical loading in the triple jump

The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32+/-0.45 m and 11.90+/-0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump (P < 0.05-0.01). In addition, electromyograms of both legs Suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.     

Biomechanical loading in the triple jump

The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32 - 0.45 m and 11.90 - 0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump ( P ? 0.05-0.01). In addition, electromyograms of both legs suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.     

太极扇对老年女性心肺功能及脂代谢的影响

以40名退休女教师作为研究对象,随机分为两组,进行为期10周的太极扇锻炼,探讨太极扇对中老年女性心肺功能及脂代谢的影响。实验结果显示,长期进行太极扇运动可以提高心肺功能,提高心血管的机能;可以减少脂肪在血管壁上的沉积,使血脂得到有效改善,对预防心血管系统的疾病具有重要作用。     

Reliability of Exercise Cardiopulmonary Responses in Older Persons With Moderate-to-Heavy Chronic Disease Burdens

The purpose of the study was to assess the reliability of cardiopulmonary responses in older adults with moderate-to-heavy chronic disease burdens. Twenty-three participants were considered to have significant chronic disease burdens. The average age was 79 ± 7.9 (70 to 94) years. Each participant was initially tested and retested within 7 days of the initial test and at approximately the same time of day. The testing protocol consisted of a treadmill protocol developed in 1995. The protocol began at a speed of 1.5 mph and 0% incline, with the speed and incline increasing by 0.5 mph and 3.0% incline every 3 min. Respiratory gases were collected using standard gas collection techniques during rest, peak exercise, and recovery. The BMDP-PC statistical software package was utilized to conduct a one-sample repeated measures analysis of variance (participants-within-repeated-measures design). Intraclass correlation estimates of what reliability would be for a single measurement or trial were calculated. Reliability estimates of .90 or better were obtained for all resting, peak exercise, and recovery variables except peak respiratory quotient (RQ) and for recovery RQ and heart rate (i.e., R = .89, .89, and .76, respectively). These findings indicate that the measurement of cardiorespiratory values are very reliable in older persons with moderate-to-heavy chronic disease burdens.