共查询到19条相似文献，搜索用时 109 毫秒
1.
利用SRM功率车以及安装在功率车上的测力系统(Powertec-System)研究不同踏蹬频率下场地自行车运动员一个踏蹬周期内作用于曲柄的切向踏蹬力特征。以8名自行车运动员为研究对象,在SRM功率车上进行10min、90rpm、120w的准备活动后,进行阻力负荷为500watt的骑行,踏蹬频率分别为100、120、130、140rpm,顺序随机选择,骑行稳定后,采集连续5s的踏蹬力数据。结果表明,随着踏蹬频率的提高,作用在左、右两侧曲柄的切向踏蹬力分量的正均值、均值、最大值减小,两侧切向踏蹬力分量之和的均值及峰值也减小(p<0.01);左、右侧正切向踏蹬力分量的起止位置、最值位置、双侧切向踏蹬力分量之和的峰值位置均随着踏蹬频率的增大而提前(p<0.01);在踏蹬周期的下半段,踏蹬频率越高,切向踏蹬力曲线越低,在踏蹬周期的上半段,踏蹬频率越高,切向踏蹬力曲线越高。 相似文献
2.
场地自行车男子短距离项目包括争先赛、凯林赛和团体竞速赛。凡是符合专项比赛要求的力量就是专项力量,场地短距离项目的专项力量是运动员在最佳传动比的前提下,达到并保持最大骑行频率的踏蹬力。场地男子短距离项目的专项力量训练应采用小负荷快速发力的训练形式,训练手段应在动作结构、肌肉用力顺序和供能方式等方面与专项运动特征相近。目前,在一般力量训练与专项力量训练的关系、专项力量训练手段等方面还需要进一步深入研究。 相似文献
3.
1 问题的提出 自行车运动,就下肢动作而言,是一种非匀速,逆时针进行,两足处以相对立方向的圆周运动。 踏蹬动作是整个下肢动作的关键,合理的踏蹬技术动作可使运动员以最小的能量消耗祈取最佳的工作效率,达到高速度行进。 合理的踏蹬动作是指下肢肌肉协调的交替收缩 相似文献
4.
运用“自行车运动员踏蹬状态测试仪”对我国高水平女子场地原地发500米计时赛项目运动员的踏蹬状态进行了研究,进一步确定了我国高水平女子自行车运动员踏蹬“死点”的区域及合理的踏蹬技术,为自行车运动员的技术训练提出了较为合理的意见与建议。 相似文献
5.
目的：对场地自行车不同传动比下大强度骑行过程中功率、频率变化进行测评,分析传统疲劳指数、频率指数和净疲劳指数在疲劳评价中的应用价值。方法：10名男子短距离自行车运动员分别使用50：12和50：13两种传动比进行两次200m俯冲骑行测试,使用SRM自行车专用功率记录仪采集骑行全程的功率和踏蹬频率,分别计算传统疲劳指数、频率指数和净疲劳指数。结果：运动员完成200m俯冲骑行到达终点前30s过程中,功率、频率前7s同时逐渐增加,8-11s功率增加但频率维持原来水平,功率在12-15s左右达到最大,此时频率约为130rpm左右,随后可见频率仍在增加,但功率逐步降低。场地自行车大坡俯冲骑行过程中,传统疲劳指数明显高于净疲劳指数,两者计算结果的差异来自与是否将频率变化包括在内。结论：净疲劳指数较传统疲劳指数更好地反映了场地自行车骑行中的功率-频率关系,并能描述不同速度下的疲劳程度。运动员可以通过适度增加传动比,降低频率来提高200m计时赛运动成绩。 相似文献
6.
通过实验测试方法,对优秀中长距离自行车运动员进行功率车测试及肌电研究,了解运动员在原地起动阶段的踏频及功率变化情况,以及在原地起动阶段和固定功率车进行踏蹬时．下肢各主要肌肉的激活时间与用力情况,以便掌握运动员骑行过程中主要的用力肌肉,加强训练的针对性和有效性。研究发现,股内侧肌和股外侧肌肌电信号表现明显,提示这两块肌肉可能为踏蹬主要发力肌肉。在踏蹬过程中,运动员的肌肉用力情况存在一定的差异,全能运动员与公路运动员相比,肌肉用力比较平均,肌力也相对要大 相似文献
7.
文章从力学的角度和形态学方面,对自行车踏蹬一周中的受力情况,选取六个点(6个角度)的踏蹬技术特征,来进行分析研究,以帮助运动员形成正确的踏蹬骑行动作。 相似文献
8.
公路自行车运动员下肢力量训练理论与方法 总被引：1，自引：0，他引：1
本文采用文献资料法,收集了有关专家对公路自行车运动员力量训练理论与方法的研究成果,结合自身多年的训练经验,从运动解剖学,运动生理学和运动训练学的角度对公路自行车运动员下肢的踏蹬动作、肌肉类型和训练方法进行了理论上和方法上的分析探讨,旨在通过提高力量训练的科学有效训练,提高公路自行车运动员的比赛成绩。 相似文献
9.
SRM训练系统在场地短距离自行车运动员专项力量训练中的应用 总被引：4，自引：0，他引：4
通过对上海市男子短距离自行车运动员在10运会前一年的比赛、训练情况进行连续追踪，应用SRM训练系统对运动员在训练和比赛情况进行分析，对SRM训练系统在自行车运动员专项力量训练中的应用进行了探讨，结果发现：（1）使用SRM训练系统可以监测自行车运动员比赛或训练中的实时情况，通过功率、速度以及频率等指标，可以反映自行车运动员专项能力的变化情况。（2）自行车运动员的运动成绩取决于专项力量的大小，而不是绝对力量的高低。（3）自行车运动员的专项力量是在自行车运动中表现出来的一种高频率的踏蹬力量。 相似文献
10.
《体育科技文献通报》1998,(10)
G872.35,G818.3,HL006 9803988自行车踏蹬速度测定分析系统的研制与应用[HL,中,A]/熊开宇,延峰,郑晓鸿,赵枝英,王瑞元//第五届全国体育科学大会论文摘要汇编.-1997.-139(TY)自行车//蹬踏//速度//测试器材//电子器材作者研制了一套适合训练现场应用的自行车踏蹬圆滑度速度测定分析系统.该系统传感器选用了美国产磁敏数字开关,体积小、灵敏度高,安装在赛车上不影响运动员的骑行.运动员踏蹬速度信息用通过牙盘上的小磁铁传递给传感器,记录在微型录音机上,记录下的信号通过专用接口电路输入到计算机,经过专用程序处理,即可得到运动员踏蹬圆滑速的准确信息.应用自行车踏蹬速度测定分析系统对我国女子优秀自行车运动员166m,200m,333m,1000m,1333m,3000m,5000m 的实际训练过程进行了测试分析.通过分析,得到我 相似文献
11.
Li L 《Research quarterly for exercise and sport》2004,75(1):16-22
The neuromuscular control aspect of cycling has been investigated through the effects of modifying posture and cadence. These studies show that changing posture has a more profound influence on neuromuscular coordination than does changing slope. Most of the changes with standing posture occur late in the downstroke: increased ankle and knee joint moment, reduced hip joint moment and greater activity in specific muscles. Due to the influence of lower extremity inertial properties, higher pedaling frequency induces more neuromuscular changes at the hip than at the knee or ankle joints. These neuromuscular adaptations to environmental and task constraints are discussed with regard to the contributions of the central nervous system and the solution provided by peripheral anatomical structure--mono- and biarticular muscles. The results indicate that training and related movement analysis should be specific to the motion, supporting the notion of task-specific training. 相似文献
12.
Robert Reed Simon Adrian Jobson Louis Passfield 《European Journal of Sport Science》2016,16(8):903-911
The cadence that maximises power output developed at the crank by an individual cyclist is conventionally determined using a laboratory test. The purpose of this study was two-fold: (i) to show that such a cadence, which we call the optimal cadence, can be determined using power output, heart-rate, and cadence measured in the field and (ii) to describe methodology to do so. For an individual cyclist's sessions, power output is related to cadence and the elicited heart-rate using a non-linear regression model. Optimal cadences are found for two riders (83 and 70 revolutions per minute, respectively); these cadences are similar to the riders’ preferred cadences (82–92?rpm and 65–75?rpm). Power output reduces by approximately 6% for cadences 20?rpm above or below optimum. Our methodology can be used by a rider to determine an optimal cadence without laboratory testing intervention: the rider will need to collect power output, heart-rate, and cadence measurements from training and racing sessions over an extended period (>6 months); ride at a range of cadences within those sessions; and calculate his/her optimal cadence using the methodology described or a software tool that implements it. 相似文献
13.
Gerda Strutzenberger Tobias Wunsch Josef Kroell Jacqueline Dastl Hermann Schwameder 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(2):97-108
Non-circular chainrings theoretically enhance cycling performance by increasing effective chainring diameter and varying crank velocity, but research has failed to consistently reproduce the benefits in cycling trials. The aim of this study was (1) to investigate the effect of different chainring shapes on sagittal knee joint moment and sagittal lower limb joint powers and (2) to investigate whether alterations are affected by cadence and workload. Fourteen elite cyclists cycled in six conditions (70, 90 and 110 rpm, each at 180 and 300 W), for 2 min each, using three chainrings of different ovalities (1.0–1.215). Kinematic data and pedal forces were collected. For most conditions, only the chainring with the highest ovality (1.215) was characterised by smaller sagittal knee joint moments, smaller relative sagittal knee joint power contribution and larger relative sagittal hip joint power contribution, which suggests a change from maximising efficiency to maximising power production. Effect sizes increased with higher cadences, but not with higher workload. This study has application for athletes, clinicians and sports equipment industry as a non-circular chainring can change joint-specific power generation and decrease knee joint moment, but certain ovality seems to be necessary to provoke this effect. 相似文献
14.
BackgroundOne-legged pedaling is of interest to elite cyclists and clinicians. However, muscular usage in 1-legged vs. 2-legged pedaling is not fully understood. Thus, the study was aimed to examine changes in leg muscle activation patterns between 2-legged and 1-legged pedaling.MethodsFifteen healthy young recreational cyclists performed both 1-legged and 2-legged pedaling trials at about 30 Watt per leg. Surface electromyography electrodes were placed on 10 major muscles of the left leg. Linear envelope electromyography data were integrated to quantify muscle activities for each crank cycle quadrant to evaluate muscle activation changes.ResultsOverall, the prescribed constant power requirements led to reduced downstroke crank torque and extension-related muscle activities (vastus lateralis, vastus medialis, and soleus) in 1-legged pedaling. Flexion-related muscle activities (biceps femoris long head, semitendinosus, lateral gastrocnemius, medial gastrocnemius, tensor fasciae latae, and tibialis anterior) in the upstroke phase increased to compensate for the absence of contralateral leg crank torque. During the upstroke, simultaneous increases were seen in the hamstrings and uni-articular knee extensors, and in the ankle plantarflexors and dorsiflexors. At the top of the crank cycle, greater hip flexor activity stabilized the pelvis.ConclusionThe observed changes in muscle activities are due to a variety of changes in mechanical aspects of the pedaling motion when pedaling with only 1 leg, including altered crank torque patterns without the contralateral leg, reduced pelvis stability, and increased knee and ankle stiffness during the upstroke. 相似文献
15.
Stability of pedalling mechanics during a prolonged cycling exercise performed at different cadences
The aim of this study was to analyse the effect of pedalling rate on the pattern of mechanical torque application and on neuromuscular fatigue during prolonged cycling exercise. Eleven well-trained individuals performed three 1-h pedalling sessions, at 50 rev.min-1, 110 rev.min-1 and a freely chosen cadence, at an intensity corresponding to 65% of their maximal aerobic power. The mechanical torque applied on the right pedal was recorded for 30 s every 5 min while pedalling. Contractile and neural properties of the quadriceps and hamstring muscles were analysed before and immediately after each of the three pedalling sessions. The post-exercise reduction in knee extensors maximal voluntary contraction was significant (P<0.01) irrespective of the cadence, but no difference was found between cadences. The use of a particular cadence did not lead to preferentially central or peripheral fatigue. An increase in cadence resulted in greater positive and negative work generated during pedalling. The mechanical pattern was not altered during the exercise, whatever the selected cadence. The present study demonstrates that despite the occurrence of neuromuscular fatigue, trained individuals maintained a stable pedalling pattern throughout an endurance cycling exercise for cadences ranging from 50 to 110 rev.min-1. 相似文献
16.
Sides D Wilson C 《Sports biomechanics / International Society of Biomechanics in Sports》2012,11(1):1-9
This study aimed to establish the nature of lower extremity intra-limb coordination variability in cycling and to investigate the coordinative adaptations that occur in response to changes in cadence and work rate. Six trained and six untrained males performed nine pedalling bouts on a cycle ergometer at various cadences and work rates (60, 90, and 120 revolutions per minute (rpm) at 120, 210, and 300W). Three-dimensional kinematic data were collected and flexion/extension angles of the ankle, knee, and hip joints were subsequently calculated. These data were used to determine two intra-limb joint couplings [hip flexion/extension-knee flexion/extension (HK) and knee flexion/extension-ankle plantar-flexion/dorsi-flexion (KA)], which were analysed using continuous relative phase analysis. Trained participants displayed significantly (p < 0.05) lower coordination variability (6.6 +/- 4.0 degrees) than untrained participants (9.2 +/- 4.7 degrees). For the trained subjects, the KA coupling displayed significantly more in-phase motion in the 120 rpm (19.2 +/- 12.3 degrees) than the 60 (30 +/- 7.1 degrees) or 90 rpm (33.1 +/- 7.4 degrees) trials and the HK coupling displayed significantly more in-phase motion in the 90 (33.3 +/- 3.4 degrees) and 120 rpm (27.9 +/- 13.6 degrees) than in the 60 rpm trial (36.4 +/- 3.5 degrees). The results of this study suggest that variability may be detrimental to performance and that a higher cadence is beneficial. However, further study of on-road cycling is necessary before any recommendations can be made. 相似文献
17.
Stability of pedalling mechanics during a prolonged cycling exercise performed at different cadences
The aim of this study was to analyse the effect of pedalling rate on the pattern of mechanical torque application and on neuromuscular fatigue during prolonged cycling exercise. Eleven well-trained individuals performed three 1-h pedalling sessions, at 50 rev?·?min?1, 110 rev?·?min?1 and a freely chosen cadence, at an intensity corresponding to 65% of their maximal aerobic power. The mechanical torque applied on the right pedal was recorded for 30?s every 5?min while pedalling. Contractile and neural properties of the quadriceps and hamstring muscles were analysed before and immediately after each of the three pedalling sessions. The post-exercise reduction in knee extensors maximal voluntary contraction was significant (P <?0.01) irrespective of the cadence, but no difference was found between cadences. The use of a particular cadence did not lead to preferentially central or peripheral fatigue. An increase in cadence resulted in greater positive and negative work generated during pedalling. The mechanical pattern was not altered during the exercise, whatever the selected cadence. The present study demonstrates that despite the occurrence of neuromuscular fatigue, trained individuals maintained a stable pedalling pattern throughout an endurance cycling exercise for cadences ranging from 50 to 110 rev?·?min?1. 相似文献
18.
In this study, we examined patterns of leg muscle recruitment and co-activation, and the relationship between muscle recruitment and cadence, in highly trained cyclists. Electromyographic (EMG) activity of the tibialis anterior, tibialis posterior, peroneus longus, gastrocnemius lateralis and soleus was recorded using intramuscular electrodes, at individual preferred cadence, 57.5, 77.5 and 92.5 rev . min(-1). The influence of electrode type and location on recorded EMG was also investigated using surface and dual intramuscular recordings. Muscle recruitment patterns varied from those previously reported, but there was little variation in muscle recruitment between these highly trained cyclists. The tibialis posterior, peroneus longus and soleus were recruited in a single, short burst of activity during the downstroke. The tibialis anterior and gastrocnemius lateralis were recruited in a biphasic and alternating manner. Contrary to existing hypotheses, our results indicate little co-activation between the tibialis posterior and peroneus longus. Peak EMG amplitude increased linearly with cadence and did not decrease at individual preferred cadence. There was little variation in patterns of muscle recruitment or co-activation with changes in cadence. Intramuscular electrode location had little influence on recorded EMG. There were significant differences between surface and intramuscular recordings from the tibialis anterior and gastrocnemius lateralis, which may explain differences between our findings and those of previous studies. 相似文献
19.
The aim of this study was to determine the response of cyclists to manipulations of cadence and power output in terms of force application and plantar pressure distribution. Two groups of cyclists, 17 recreational and 12 competitive, rode at three nominal cadences (60, 80, 100 rev min -1 ) and four power outputs (100, 200, 300, 400 W) while simultaneous force and in-shoe pressure data were collected. Two piezoelectric triaxial force transducers mounted in the right pedal measured components of the pedal force and orientation, and a discrete transducer system with 12 transducers recorded the in-shoe pressures. Force application was characterized by calculating peak resultant and peak effective pedal forces and positive and negative impulses. In-shoe pressures were analysed as peak pressures and as the percent relative load. The force data showed no significant group effect but there was a cadence and power main effect. The impulse data showed a significant three-way interaction. Increased cadence resulted in a decreased positive impulse, while increased power output resulted in an increased impulse. The competitive group produced less positive impulse but the difference became less at higher cadences. Few between-group differences were found in pressure, notable only in the pressure under the first metatarsal region. This showed a consistent pattern of in-shoe pressure distribution, where the primary loading structures were the first metatarsal and hallux. There was no indication that pressure at specific sites influenced the pedal force application. The absence of group differences indicated that pressure distribution was not the result of training, but reflected the intrinsic relationship between the foot, the shoe and the pedal. 相似文献