女子拳击运动员上肢和腰部肌肉力量训练的肌电分析

目的：利用肌电指标分析拳击运动员上肢和腰部肌肉力量训练效果。方法：用Mega公司的ME6000肌电图仪记录分析10名女子拳击运动员上臂肱二头肌（主动肌）与肱三头肌（拮抗肌）、前臂屈肌（主动肌）与伸肌（拮抗肌）和腰部肌群的运动诱发肌电,规定运动为手持2.5 kg的哑铃负荷进行直拳空击运动直至局部肌肉力竭。结果：直拳空击运动至局部肌肉力竭过程中,上肢拮抗肌的中位频率（MF）下降幅度和速度大于相对应的主动肌,且从肌群作功来看,主动肌作功百分比较拮抗肌大。其中9名普通运动员腰肌的肌电频率（MF）均值较1名指定样本世界冠军的下降缓慢,而且其作功百分比都较小。结论：通过对普通女子拳击运动员上肢和腰部肌群肌电指标测试与世界冠军的比较分析,提示本研究中所测普通拳击运动员拮抗肌和腰部肌肉力量训练不足,有待加强该部肌肉的力量训练。     

MOTOmed下肢智能运动训练联合运动想象疗法对脑卒中偏瘫患者下肢功能、步行能力和躯干屈伸肌群肌力的影响

摘要 目的：探讨MOTOmed下肢智能运动训练联合运动想象疗法对脑卒中偏瘫患者下肢功能、步行能力和躯干屈伸肌群肌力的影响。方法：148例脑卒中偏瘫患者来源于我院2019年5月~2021年5月期间我院接收的患者,根据随机数字表法分为对照组（n=74,常规康复训练的基础上结合MOTOmed下肢智能运动训练）和研究组（n=74,对照组的基础上结合运动想象疗法）。两组均干预12周。对比两组下肢功能、步行能力和躯干屈伸肌群肌力变化。结果：两组干预12周后Fugl-Meyer运动功能量表（FMA）、Barthel指数（BI）、功能性步行能力分级量表（FAC）评分升高,且研究组高于对照组（P<0.05）。两组干预12周后步频、步速、跨步长比率升高,且研究组高于对照组（P<0.05）。两组干预12周后健侧腹直肌、竖脊肌表面肌电信号的均方根值未见明显变化,且组间同时点对比无差异（P>0.05）。两组干预12周后患侧腹直肌、竖脊肌表面肌电信号的均方根值升高,且研究组高于对照组（P<0.05）。结论：脑卒中偏瘫患者在MOTOmed下肢智能运动训练的基础上进行运动想象疗法,可促进下肢功能改善,提高步行能力,同时还可改善患侧躯干屈伸肌群肌力。     

行走模式对人体下肢三维步态、肌电信号的影响

目的:揭示人体在主动和被动两种行走模式下的步态特征与下肢主要肌群的肌电信号变化规律。方法:选取12名在校男大学生,通过Greenjog履带式自发力跑台和h/p/cosmos电动跑台建立主动式和被动式行走模型,先后在两种模式下以3种递增速度即慢速(2 km/h)、常速(4 km/h)、和快速(6 km/h)进行一次性步行运动,运用三维运动捕捉分析系统和表面肌电测试仪,分别对每种速度采集2 min的连续三维步态和肌电信号数据。结果:慢速时,被动式行走的支撑相占比显著高于主动式行走(P<0.05),而摆动相占比和膝关节角度变化值则显著低于主动式行走(P<0.05);常速时,被动式行走的膝关节角度变化值和股二头肌积分肌电值显著低于主动式行走(P<0.05);快速时,被动式行走的膝关节、踝关节角度变化值和股二头肌积分肌电值显著低于主动式行走(P<0.01);此外,随着步行速度的增加,被动式行走的胫骨前肌积分肌电值呈现显著增高的趋势(P<0.05)。结论:随着步行速度的增加,人体主动步行时的膝关节活动范围更充分,对主动肌的锻炼作用更明显。     

等张收缩肱二头肌特性的多信号结合研究

表面肌电图（Surface Electromyography,SEMG）表征了骨骼肌的电生理特性;而肌动图（Mechanomyography,MMG）则是反映骨骼肌收缩时的肌纤维振动的力学特性。超声可以清晰的观测骨骼肌空间形态变化,我们把超声扫描骨骼肌得到的有关骨骼肌结构形态变化的信息定义为“声肌图（Sonomyography,SMG）”。本文同步采集了肘关节屈伸引起的肱二头肌等张收缩时的超声图像、肘关节角度、SEMG和MMG信号,初步分析了不同信号之间的关系,多角度结合研究了骨骼肌的特性,表明了多信号结合研究骨骼肌特性是发展的趋势。     

串脉冲致兔隔肌疲劳的动物模型

本实验采用串脉冲刺激兔隔神经法复制了家兔膈肌疲劳模型。测定隔肌张力（Ｔｄｉ）、跨膈压（Ｐｄｉ）及其频率特性（Ｔｄｉ－Ｆ、Ｐｄｉ－Ｆ）、呼吸流速（Ｖ）、肺阻力（ＲＬ）、膈肌肌电图（ＥＭＧｄｉ等作为评价膈肌收缩力量的指标。结果发现：经串脉冲刺激后,Ｐｄｉ－Ｆ曲线在３０、５０和１００Ｈｚ时显著降低,Ｐｄｉ、Ｔｄｉ、Ｖ和跨肺压均显著下降。氨茶碱可增加隔肌收缩力,延缓膈肌疲劳过程。结果提示,用串脉冲刺激兔膈神经法建立的模型是一种灵敏、可靠和稳定的膈肌疲劳动物模型。     

等长收缩诱发肌肉疲劳及恢复过程中表面肌电信号特征变化规律

运用线性和非线性分析方法分析不同强度等长收缩诱发局部肌肉疲劳及恢复过程中表面肌电信号（surface electromyogram,sEMG）特征的变化规律,探讨影响sEMG信号变化的可能原因和机制.结果显示,在肱二头肌疲劳收缩过程中,sEMG的特征指标平均肌电值（average EMG,AEMG）、平均功率频率（mean power frequency,MPF）、Lempel-Ziv复杂度（Lempel-Ziv complexity,C（n））和确定性线段百分数（Determinism%,% DET）的变化具有良好的规律性.恢复期AEMG没有表现出规律性的变化,MPF、C（n）和?T在恢复期2秒即开始显著恢复,在前10秒恢复很快,随后恢复速度变慢.恢复初期sEMG信号特征的快速变化提示中枢控制因素可能发挥更大作用.     

聂跳蚜属(蚜科：跳蚜亚科) 订正及一新种记述

记述了聂跳蚜属Nevskyella Ossiannilsson 世界全部已知和新发现种类共5种： 蘑菇聂跳蚜N. fungifera (Ossiannilsson), 华聂跳蚜N. sinensis (Zhang, Zhang and Zhong, 1995)（新组合）, 瘤聂跳蚜N. tuberculata Zhang and Zhang,拟蘑菇聂跳蚜N. similifungifera sp. Nov.和法国聂跳蚜N. meridionalis HilleRis Lambers and vanden Bosch,其中前4种在中国有分布。文中提供了分种检索表、形态学描述、寄主植物、地理分布和生物学资料。基于前、中足股节扩展,胫节基部加粗,头部侧缘无毛以及后足胫节外侧缘毛正常,提出了新组合华聂跳蚜N. sinensis (Zhang, Zhang and Zhong, 1995) 。蘑菇聂跳蚜以往报道的中国分布记录部分属误定,被定为新种拟蘑菇聂跳蚜N. similifungifera sp. nov.。模式标本保存在中国科学院动物研究所（IZAS）和英国自然历史博物馆昆虫部（BMNH）。     

MOTOmed下肢运动训练联合等速肌力训练对脑卒中偏瘫患者下肢运动功能、下肢肌张力和步行步态功能的影响

摘要 目的：观察MOTOmed下肢运动训练联合等速肌力训练在脑卒中偏瘫患者的应用价值。方法：根据随机数字表法将2019年5月-2022年12月期间南京医科大学附属脑科医院收治的158例脑卒中偏瘫患者分为对照组（n=79,接受等速肌力训练）和观察组（n=79,对照组基础上接受MOTOmed下肢运动训练）。对比两组下肢运动功能、下肢肌张力、步行步态功能。结果：干预12周后,两组Fugl-Meyer运动功能评定量表（FMA）、Berg平衡量表（BBS）评分升高,且观察组高于对照组同期（P<0.05）。干预12周后,两组膝关节后伸（FKE）、前屈（FKF）、髋关节后伸（FHE）、前屈（FHF） 肌张力升高,且观察组高于对照组同期（P<0.05）。干预12周后,两组步速、步频、步长、功能性步行分级量表（FAC）评分升高,且观察组高于对照组同期（P<0.05）。结论：MOTOmed下肢运动训练联合等速肌力训练治疗脑卒中偏瘫患者,可有效改善下肢运动功能、下肢肌张力以及步行步态功能。     

氨茶碱,环磷酸泉苷葡甲胺（MCA）对兔膈肌功能的影响

目的：观察氨茶碱、环磷酸腺苷葡甲胺对兔跨膈压及膈肌电活动的影响,以中肌疲劳的治疗效果提供实难依据。方法：刺激双侧膈神经４０ｍｉｎ复制膈肌疲劳（ＤｉＦ）动物模型,动物随机分三组（ｎ＝６）：氨茶碱组（１０ｍｇ／ｋｇ）、ＭＣＡ组（１０ｍｇ／ｋｇ）,合用组（氨茶碱１０ｍｇ／ｋｇ＋葡甲胺ｃＡＭＰ（１０ｍｇ／ｋｇ）。于ＤｉＦ前、ＤｉＦ及给药后３０、６０ｍｉｎ记录中压（Ｐｄｉ）;记录膈肌肌电图（ＥＭＧｄｉ）并输     

举重训练对男子肌比力、肌纤维的影响

安排9名有一定训练的青少年运动员参加10周举重训练。每周6次,每次8小时。训练前后用电子计算机—X线断层扫描技术(CT)测量大腿肌肉横断面积,股外肌针刺活检取样测定Ⅰ、Ⅱ型肌纤维％和面积。测定大腿伸膝肌最大随意等长力量。将结果(实验前、后)与对照组(13名无训练者)和优秀举重运动员(健将3人、一级4人)进行比较。结果表明,有训练人(实验前、后和优秀)与没有训练人(对照)在肌比力上存有差别。短、长期举重训练后,肌比力与Ⅱ型肌纤维％呈正相关。短、长期举重训练不曾改变肌纤维类型分布。举重训练对Ⅱ型肌纤维有选择性作用,且这个作用不受年龄的影响。结果还提示,肌比力的变化及肌比力与肌纤维之间的关系都会受运动项目专项特点的影响。     

A multivariate approach to predicting knee extensor performance

The impact of two predictor variables (estimated knee extensor fast-twitch fiber percentage, body mass) on performance measures (vertical jump power output, leg press peak angular velocity) were examined. Subjects (25 men, 27 women) performed 5 workouts involving 2 vertical jump, leg press, and 50-repetition isokinetic tests (to estimate knee extensor fast-twitch fiber percentage). Multivariate regression determined the following significant (p < 0.05) vertical jump equations: predicted male power output = -59.3464 + 1.566 (estimated knee extensor fast-twitch muscle fiber percent) + 15.7884 (body mass), predicted female power output = 36.1574 + 3.4248 (estimated knee extensor fast-twitch muscle fiber percent) + 9.8633 (body mass). Leg press peak angular velocity equations were insignificant by gender; thus, pooled data yielded the following: predicted leg press peak angular velocity = 18.6187 + 0.235 (estimated knee extensor fast-twitch muscle fiber percent) + 0.3801 (body mass). Body mass explained more variance for each performance measure.     

Muscular co-contraction during walking and landing from a jump: comparison between genders and influence of activity level.

BACKGROUND: Women have higher rates of knee ligament injury than men. Co-contraction of knee muscles is proposed to be an important mechanism to protect the joint from injuries. HYPOTHESIS: Females have lower co-contraction levels when compared to males. STUDY DESIGN: Exploratory, cross-sectional design. METHODS: Thirty-six men and women equally divided into four groups according to gender and activity level (sedentary and athletic) were compared in relation to vastus lateralis and biceps femoris co-contraction before heel strike during level walking and before floor contact during landing from a jump. Muscular co-contraction was assessed by surface electromyography. Correlations between co-contraction and ligament laxity, extensor and flexor work, and flexion/extension torque ratio were also analyzed. RESULTS: No differences between genders were found in the studied situations (p0.381). During walking, co-contraction was greater in sedentary women compared to athletic women (p=0.002). A moderate inverse correlation was found between co-contraction during walking and women extensor (r=-0.613; p=0.007) and flexor (r=-0.575; p=0.012) work. During landing from a jump, no variables correlated to co-contraction in any of the groups tested (r0.477; p0.061). CONCLUSION: Co-contraction levels were not different between genders. Results suggest that women compensate strength deficits by means of increasing activation levels, possibly to generate adequate joint stiffness to meet stabilization demands. However, this is not evident in a more stressful activity like landing from a jump. CLINICAL RELEVANCE: This study contributes to a better understanding of the factors related to joint protection in females, who are at a greater risk of ligament injuries.     

The metatibial extensor and flexor tendons in Coleoptera

The metatibiae of genera in several families of Coleoptera with enlarged metafemora are examined, including Chrysomelidae (Alticinae, Galerucinae, Sagrinae), Bruchidae (Pachymerinae, Rhae-binae, Eubaptinae, Bruchinae), Scirtidae and Oedemeridae. There is an evident pattern concerning the relative size of the tibial extensor and flexor tendons that is dependent on the type of hind leg movement of a specific beetle group. Beetle groups that jump (e.g. Alticinae, Scirtidae) always have a greatly enlarged metatibial extensor tendon and associated musculature. However, other groups with swollen metafemora that do not jump have enlarged metatibial flexor tendons with the associated musculature for holding/grasping onto the vegetation (Sagrinae, Bruchidae) or onto the female during copulation (male Oedemera). This indicates a strong functional relationship between Sagrinae and Bruchidae, both with large flexor tendons, and between the Alticinae and Galerucinae, with relatively large extensor tendons; these two cases may also have phylogenetic meaning. This pattern of the metatibial extensor and flexor tendon size related to function is presumably true for at least all other Coleoptera.     

Use of an overhead goal alters vertical jump performance and biomechanics

This study examined whether an extrinsic motivator, such as an overhead goal, during a plyometric jump may alter movement biomechanics. Our purpose was to examine the effects of an overhead goal on vertical jump height and lower-extremity biomechanics during a drop vertical jump and to compare the effects on female (N = 18) versus male (N = 17) athletes. Drop vertical jump was performed both with and without the use of an overhead goal. Greater vertical jump height (p = 0.002) and maximum takeoff external knee flexion (quadriceps) moment (p = 0.04) were attained with the overhead goal condition versus no overhead goal. Men had significantly greater vertical jump height (p < 0.001), maximum takeoff vertical force (p = 0.009), and maximum takeoff hip extensor moment (p = 0.02) compared with women. A significant gender x overhead goal interaction was found for stance time (p = 0.02) and maximum ankle (p = 0.04) and knee flexion angles (p = 0.04), with shorter stance times and lower angles in men during overhead goal time. These results indicate that overhead goals may be incorporated during training and testing protocols to alter lower-extremity biomechanics and can increase performance.     

Leg and calf press training modes and their impact on jump performance adaptations

To examine the effects of resistance exercise (REX) mode on jump performance, subjects were assigned to one of three groups over a 6-week period with no cross-over. Subjects were assigned to leg and calf press REX on either a standard (n = 10) or ergometer (n = 9) device while a third group (n = 9) served as controls (CTRL). REX subjects worked out twice per week, which consisted of a three-set, 10-repetition paradigm for leg and calf press exercises. Immediately before and after the 6-week period, subjects performed tests that assessed jump (standing vertical jump, four-jump test protocol, depth jump) ability, while a fourth estimated knee extensor fast-twitch percentage (FT%) from fatigue incurred through a 50-repetition isokinetic protocol. Data analyses utilized 3 x 2 (group x time) repeated-measures ANCOVAs. Several dependent variables showed effects by group (standard REX, ergometer REX > CTRL) and time (post > pre). An interaction occurred for explosive leg power factor, a four-jump test variable, with standard REX post-test values as the interaction source. A trend for an interaction occurred for depth jump hang time, as ergometer REX values improved over time. Results suggest that mode-specific adaptations occur with REX training. Thus, athletes are best served with the selection of a REX device that is most specific to the demands of their jump performance task.     

Potentiation of knee extensor contraction by antagonist conditioning contraction at several intensities

The purpose of this study was to examine the effect of graded conditioning contractions of the antagonist knee flexor muscles on the output characteristics of knee extensor muscles in healthy humans. Eight male university students performed maximum isometric contractions of knee extensors, preceded by isometric conditioning contractions of the antagonist knee flexors. The developed force and electromyographic (EMG) amplitudes of the knee extensors after the conditioning contraction were measured and compared with those of simple knee extension without conditioning. The forces of the conditioning flexor contraction were set at three levels: low (20% of maximum voluntary contraction: MVC), moderate (60% of MVC), and high (100% of MVC). The EMG amplitudes of the vastus medialis, vastus lateralis, and rectus femoris muscle were recorded and the root mean square amplitudes were calculated. The strongest enhancement of the extension force was obtained by moderate intensity conditioning contraction (108.95+/-1.87% of simple knee extension), although high intensity conditioning also induced a significant increase (105.41+/-2.69%). Low intensity conditioning did not cause a significant enhancement of the contraction force (103.17+/-2.99%). Similarly, the EMG amplitudes were significantly increased by moderate and/or high conditioning. These results suggest that antagonist conditioning contraction of moderate intensities is sufficient and may be optimal to potentiate knee extensor contraction.     

Isokinetic knee joint evaluation in track and field events

The purpose of this study was to evaluate maximal torque of the knee flexors and extensors, flexor/extensor ratios, and maximal torque differences between the 2 lower extremities in young track and field athletes. Forty male track and field athletes 13-17 years old and 20 male nonathletes of the same age participated in the study. Athletes were divided into 4 groups according to their age and event (12 runners and 10 jumpers 13-15 years old, 12 runners and 6 jumpers 16-17 years old) and nonathletes into 2 groups of the same age. Maximal torque evaluation of knee flexors and extensors was performed on an isokinetic dynamometer at 60°·s(-1). At the age of 16-17 years, jumpers exhibited higher strength values at extension than did runners and nonathletes, whereas at the age of 13-15 years, no significant differences were found between events. Younger athletes were weaker than older athletes at flexion. Runners and jumpers were stronger than nonathletes in all relative peak torque parameters. Nonathletes exhibited a higher flexor/extensor ratio compared with runners and jumpers. Strength imbalance in athletes was found between the 2 lower extremities in knee flexors and extensors and also at flexor/extensor ratio of the same extremity. Young track and field athletes exhibit strength imbalances that could reduce their athletic performance, and specific strength training for the weak extremity may be needed.     

Muscle strength assessment from functional performance tests: role of body size

The aim of the study was to test the hypothesis that the body size plays an important role in assessment of muscle ability to exert force by standard functional performance tests. Twenty-one male students were tested on maximal isometric lift, one leg rising, vertical jump, and box lift tests, and the maximal isokinetic strength of hip and knee extensors was also recorded. When indices of the 4 functional performance tests were related to the strength of each of the 2 leg extensor muscle groups, only maximal isometric lift demonstrated positive correlation with knee extensors strength. When muscle strength was corrected for body mass, however, the aforementioned relationship became insignificant, but the 1 leg rising performance demonstrated a positive relationship with knee extensor strength. In addition, maximal isometric lift and 1 leg rising test performance provided positive and negative correlation, respectively, with body mass. The obtained findings were in line with the effects of scale applied on the tested performance. We generally conclude that the assessment of muscle capability to exert force based on some standard functional performance tests could be confounded by the body size effect.     

Activation varies among the knee extensor muscles during a submaximal fatiguing contraction in the seated and supine postures.

Ten young men sustained an isometric contraction of the knee extensor muscles at 20% of the maximum voluntary contraction (MVC) torque on three separate occasions in a seated posture. Subjects performed an isometric knee extension contraction on a fourth occasion in a supine posture. The time to task failure for the seated posture was similar across sessions (291 +/- 84 s; P > 0.05), and the MVC torque was similarly reduced across sessions after the fatiguing contraction (42 +/- 12%). The rate of increase in electromyograph (EMG) activity (%MVC) and torque fluctuations during the fatiguing contractions were similar across sessions. However, the rate of increase in EMG differed among the knee extensor muscles: the rectus femoris began at a greater amplitude (31.5 +/- 11.0%) compared with the vastus lateralis and vastus medialis muscles (18.8 +/- 5.3%), but it ended at a similar value (45.4 +/- 3.1%). The time to task failure and increase in EMG activity were similar for the seated and supine tasks; however, the reduction in MVC torque was greater for the seated posture. These findings indicate that the time to task failure for the knee extensor muscles that have a common tendon insertion did not alter over repeat sessions as had been observed for the elbow flexor muscles (Hunter SK and Enoka RM. J Appl Physiol 94: 108-118, 2003).     

Acute effect of whole body vibration on isometric strength,squat jump,and flexibility in well-trained combat athletes

The purpose of this study was to investigate the effect of whole body vibration (WBV) training on maximal strength, squat jump, and flexibility of well-trained combat athletes. Twelve female and 8 male combat athletes (age: 22.8 ± 3.1 years, mass: 65.4 ± 10.7 kg, height: 168.8 ± 8.8 cm, training experience: 11.6 ± 4.7 years, training volume: 9.3 ± 2.8 hours/week) participated in this study. The study consisted of three sessions separated by 48 hours. The first session was conducted for familiarization. In the subsequent two sessions, participants performed WBV or sham intervention in a randomized, balanced order. During WBV intervention, four isometric exercises were performed (26 Hz, 4 mm). During the sham intervention, participants performed the same WBV intervention without vibration treatment (0 Hz, 0 mm). Hand grip, squat jump, trunk flexion, and isometric leg strength tests were performed after each intervention. The results of a two-factor (pre-post[2] × intervention[2]) repeated measures ANOVA revealed a significant interaction (p = 0.018) of pre-post × intervention only for the hand grip test, indicating a significant performance increase of moderate effect (net increase of 2.48%, d = 0.61) after WBV intervention. Squat jump, trunk flexion, and isometric leg strength performances were not affected by WBV. In conclusion, the WBV protocol used in this study potentiated hand grip performance, but did not enhance squat jump, trunk flexion, or isometric leg strength in well-trained combat athletes.