Fundamental frequency and tracheal pressure during three types of vocalizations elicited from anesthetized dogs

Electrical stimulation of the midbrain was used to elicit a variety of vocalizations from six anesthetized dogs. This study was conducted to investigate the ranges of and relationships between fundamental frequency of the vocalizations (F₀) and tracheal pressure (P_t) produced during the vocalizations. The vocalizations were described according to type (growl, howl, and whine); F₀ and P_t, as well as patterns of laryngeal muscle activity, were examined for each vocalization type. Natural-sounding growl and howl vocalizations were elicited from five dogs; three dogs also produced whines. With few exceptions, F₀ was categorically different for the three vocalization types (low for growls, average for howls, very high for whines). P_t values overlapped for the three vocalization types, although, on average, howls were produced with greater P_t than growls. Patterns and degrees of laryngeal muscle activity varied across and within vocalization types, but general findings were consistent with the presumed function of most of the muscles. Laryngeal muscle activity may help explain some of the variability in the acoustic and aerodynamic data.     

股后肌群训练对提高短跑速度影响的研究

针对基层短跑教学训练实践,突出股后股群训练,通过教学对比实验,表明股后肌群训练能有效提高影响短跑速度的相关参数指标,从而提高短跑速度,股后股群训练对基层初级短跑运动员短跑速度的提高有重要意义。     

斑胸草雀鸣肌的形态观察

运用解剖学技术对斑胸草雀的左右侧鸣肌进行解剖,并对其进行测量.结果表明,斑胸草雀有2对外鸣肌和4对内鸣肌.两侧鸣肌质量差异显著,右侧较重.两侧NX IIts的直径差异显著,右侧较粗.在形态学上验证了鸣肌和NX IIts的右侧优势.初步分析了鸣肌各部分的结构及功能,为进一步研究鸣肌在鸣禽鸣唱过程中的作用提供了基础资料.     

Laryngeal and respiratory activity during vocalization in macaque monkeys

The present study describes the laryngeal and respiratory muscle activity associated with vocalizations in macaque monkeys. During the bark vocalization, a short, aperiodic call, the cricothyroid, thyroarytenoid, rectus abdominis, and intercostals were active while the posterior cricoarytenoid and diaphragm were quiet. During the coo vocalization, a longer, clear call, the cricothyroid, thyroarytenoid, intercostals, rectus abdominis, and diaphragm were active. In one monkey, the posterior cricoarytenoid was also active during the call, while in another monkey it was not. Laryngeal muscle activity was correlated with the amplitude and duration of the coo call. Results suggest that the amplitude and duration differences between calls are determined primarily by laryngeal modification of the airflow, and that the differences in posterior cricoarytenoid activity may be due to differences in voice intensity.     

蟋蟀鸣叫拮抗肌的运动神经形态

蟋蟀的鸣叫运动是通过8对中胸肌肉束的运动来完成的．按照肌肉的机能分组，参与蟋蟀鸣叫运动的中胸肌肉束可被分为相互拮抗的升肌作用组和降肌作用组．其中的一对拮抗肌103a肌(升肌)和M103b肌(降肌)受中胸神经节的第三侧根即N3侧根的c4(N3-c4)分枝支配．采用逆行染色法。结果表明支配103a肌和103b肌的运动神经的细胞体分布于中胸神经节的背侧侧壁上，二者都有一个细胞体位于与前胸神经节相连的纵连合索基部，轴突分为3个主要分枝，树突在同侧的背侧表面广泛分布．     

股后肌和小腿三头肌蹬地拉伤的分析

采集了不同运动项目引起的股后肌和小腿三头肌蹬地拉伤的病例92份,结果表明,业余运动员蹬地动作引起股后肌和小腿三头肌的拉伤,其中半腱肌和半膜肌拉伤多于股二头肌,腓肠肌内侧头拉伤多于外侧,腿后屈肌的后内侧部多于后外侧部,疾跑后蹬引起肌肉拉伤的部位多偏向于股后,向上跳起的蹬地动作引起肌肉拉伤的部位似有相对下移小腿的趋势.     

关于速滑蹬冰动作的实效性分析

运用运动生物力学方法,对膝关节在蹬冰过程中的动态变化进行了分析,并采用人体肢体检测与恢复系统,对膝、髋伸肌群的工作特点进行了探讨.结果表明:(1)膝关节点在蹬伸过程中的位置变化是向前并且向下,而髋关节点却是向前且偏上;(2)左、右伸膝肌群峰值力矩在高速区有显著性差异,240(°) s以上是速滑的常用速度区;(3)训练中肌群力量的发展往往有收缩速度区的差别.     

Influence of body posture and lung volume on subglottal pressure control during singing

The role of different breathing muscles during singing was investigated by synchronously recording EMG, pressure, and sound signals, using lung volume and gravity as experimental parameters. Surface EMG signals from the external and internal intercostals, the diaphragm, and the abdominal oblique muscles were recorded, while two singer subjects performed various singing tasks associated with rapid and precise changes of subglottal pressure. Esophageal and gastric pressures were measured by pressure transducers, and lung volume by means of impedance plethysmography. The results show that the breathing system efficiently compensates for drastic differences in the mechanics of the breathing apparatus, caused by differences in lung volume and gravity induced by changes of body posture.     

健美肌肉力量训练理论与实践的应用研究

增大肌肉围度的健美训练强度通常控制在70%-80%,而针对肌肉最大力量和爆发力训练增大肌肉围度的理论以及实践应用的研究较少。肌肉的力量决定了肌肉围度,为指导健美练习者科学地进行力量训练,寻找健美训练中最为有效的内容,通过训练经验和实验结果以及对国外文献中所获得的资料分析发现,合理的极限力量和爆发力的训练更有助于健美训练者肌肉围度的增加和力量素质的增强。