非特异性慢性腰背痛飞行员与无症状飞行员之间腰部竖脊肌表面肌电特征比较（摘要）

目的非特异性慢性腰背痛飞行员与无症状飞行员之间腰部竖脊肌表面肌电特征比较,为飞行员非特异性慢性腰背痛患者的客观诊断提供依据。方法用芬兰MEGA公司ME6000一T8表面肌电仪测量43名非特异性慢性腰背痛飞行员与9名无症状飞行员腰部竖脊肌等长收缩与站立位屈伸运动时表面肌电。     

高速气流吹袭损伤及其防护

分析了高速气流吹袭造成的人体损伤，叙述了人体动力学模型和物理模型的作用。指出：头颈部防护应进行一体化设计，而且，颈部肌群主动收缩对抗头盔升力的效果是十分显著的。要使防护装备达到最佳效果，必须在充分考虑人体的生理特性的基础上进行。     

高速气流吹袭损伤及其防护

分析了高速气流吹袭造成的人体损伤，论述了人体动力学模型和物理模型的作用。指出：头颈部防护应进行一体化设计，而且，颈部肌群主动收缩对抗头盔升力的效果是十分显著的。要使防护装备达到最佳效果，必须在充分考虑人体的生理特性的基础上进行。     

肩峰下撞击综合征患者肩胛肌群肌力与肩峰下间隙变化的相关性研究

目的：比较肩峰下撞击综合征(SIS)患者和正常人群肩胛肌群肌力和肩峰下间隙的差异，探究SIS患者肩胛肌群肌力大小改变与肩峰下间隙变化之间的关系。方法：选取50名SIS患者纳入SIS组，年龄 31.40 ± 6.51 岁，男 29、女 21，肩痛持续时间 8.79 ± 6.89 月；25 名正常健康人纳入正常组，年龄 29.40± 6.44岁，男14、女11。采用肌骨超声测试受试者在肩外展0°、30°和60°的肩峰-肱骨距离(AHD)，作为肩峰下间隙的评价指标；采用 Micro FET2 手持式测力计测试受试者的斜方肌上束(UT)、斜方肌中束(MT)、斜方肌下束(LT)以及前锯肌(SA)的最大等长收缩肌力，并进行标准化(最大等长收缩肌力/体重)。比较SIS组和正常组的AHD、肩胛肌群肌力大小的差异，分析SIS患者肩胛肌群肌力的改变与AHD变化的关系。结果：随着肩外展角度的增加，SIS组和正常组的AHD均逐渐减少，在肩外展30°到60°的过程中，SIS组AHD的变化量(AHD_30°-60°)显著大于正常组(P<0.05)；在肩外展0°到60°的过程中，SIS组A...     

大脑精确计时增强枕-顶区alpha波

目的：头戴式设备虽能够提升作战效能,但会导致头盔质心偏移和颈部关节力矩增加,增加飞行员颈部损伤的风险。为了保障飞行员健康,有必要开展飞行员颈部损伤评估。方法：开展了穿戴头盔的颈部肌肉疲劳实验,获取胸锁乳突肌、斜方肌和头夹肌的sEMG。利用变分模态分解方法将sEMG分解为若干模态分量,提取模态分量的多尺度熵,并将其作为特征向量,利用Fisher判别进行颈部损伤分类。结果：头盔质量特性的变化会导致肌肉信号模态分量的多尺度熵和中心频率的变化,而这种变化可以作为颈部肌肉的疲劳损伤分类评价的依据。结论：利用变分模态分解后的模态分量的多尺度熵,能较为合理地进行颈部肌肉疲劳损伤分类,可为飞行员颈部损伤的评估提供一定的方法支持。     

飞行员颈痛风险因素分析

目的 调查对飞行员颈痛情况,分析颈痛风险因素,为飞行员颈痛的防治和康复干预提供理论依据。方法 2019年7月—2020年11月招募飞行员284人,对其进行颈痛情况问卷调查及颈部功能评估的横断面研究,采用Logistic回归模型进行颈痛风险因素筛选。结果 共获得217名飞行员的有效数据,包括歼击机118人,直升机52人,运输机47人。飞行员近3个月颈痛发病率为29.0%,其中歼击机、直升机和运输机飞行员分别为30.5%、36.5%和17.0%。3个机种飞行员的身高、周飞行时间、颈部训练情况、饮酒习惯、上背痛、颈屈肌力、伸肌力、左侧屈力、右侧屈力、左上旋力、右上旋力、左下旋力、右下旋力和颈深屈肌激活差异有统计学意义（P均<0.05）。调整年龄和总飞行时间后,飞行员颈痛的危险因素是上背痛（OR=6.956,95%CI:2.167～22.232）,保护因素是颈深屈肌激活（OR=0.146,95%CI:0.033～0.272）;歼击机飞行员颈痛的危险因素是上背痛（OR=17.718,95%CI:2.034～154.362）;保护因素是颈部左侧屈力量（OR=0.015,95%CI:0.001...     

战斗机飞行员颈部疲劳损伤评估

目的头戴式设备虽能够提升作战效能,但会导致头盔质心偏移和颈部关节力矩增加,增加飞行员颈部损伤的风险。为了保障飞行员健康,有必要开展飞行员颈部损伤评估。方法开展了10名受试者穿戴2种头盔的颈部肌肉疲劳实验,获取胸锁乳突肌、斜方肌和头夹肌的sEMG。利用变分模态分解方法将sEMG分解为若干模态分量,提取模态分量的多尺度熵,并将其作为特征向量,利用Fisher判别进行颈部损伤分类。结果头盔质量特性的变化会导致肌肉信号模态分量的多尺度熵和中心频率的变化。头夹肌分量7的MsEn容量易受头部穿戴设备的影响(F=3.499,P=0.045);斜方肌分量2(F=5.650,P=0.009),分量4(F=4.027,P=0.029)和分量7(F=13.064,P=0.000)的MsEn较易受头部穿戴设备的影响;胸锁乳突肌的分量1(F=20.628,P=0.000),分量2(F=3.339,P=0.051),分量3(F=4.368,P=0.023),分量4(F=42.527,P=0.000)和分量6(F=14.628,P=0.000)容易受头盔质量特性的影响。结论利用变分模态分解后的模态分量的多尺度熵,能较为合理地进行颈部肌肉疲劳损伤分类,可为飞行员颈部损伤的评估提供一定的方法支持。     

西班牙空军高性能战斗机飞行员的颈椎磁共振图像

前言 本研究是在完全无症状或颈退行性病变的飞行员危险人群中调查颈椎异常的存在。 方法 对17名战斗机飞行员(平均年龄30岁,平均飞行时间1619h)和22名货运飞行员(平均年龄29岁,平均飞行时间1272h)使用磁共振图像(MRI)和常规的颈部放射学检查。战斗机和货运飞行员的检查结果分别由两名事先不知受试者飞行状态的神经放射学专家阅读     

歼击机飞行员非特异性慢性腰背痛患者腰部竖脊肌表面肌电特征

目的测量分析非特异性慢性腰背痛歼击机飞行员与对照组歼击机飞行员腰部竖脊肌表面肌电（surface electromyography,sEMG）,为歼击机飞行员非特异性慢性腰背痛患者的客观诊断评价提供参考依据。方法芬兰ME6000-T8表面肌电仪测量39名非特异性慢性腰背痛歼击机飞行员（病例组）与12名无症状歼击机飞行员（对照组）腰部竖脊肌俯卧位等长收缩、站立位屈伸运动时的表面肌电。MEGAWIN700046,2．4版软件处理等长收缩时疲劳性肌电信号,获取中位频率下降率（median frequency slope,MFs）、平均功率频率下降率（mean power frequency slope,MPFs）、过零率下降频率（zero crossing rate slope,ZCRs）、平均电压下降率（average electromyography slope,AEMGs）,分析屈伸动作时的肌电信号,得出屈曲伸直动作时的平均肌电电压（averageelectromyography,AEMG）,并由此计算屈曲伸直比（flexion extension ratio,FER）。分析病例组与对照组各指标的差别。结果竖脊肌等长收缩时病例组与对照组疲劳性肌电指标之间无统计学差异。屈伸运动时病例组与对照组AEMG及FER指标有统计学差异（t=1．979～5．387,P％0．05或P％0．01）。结论非特异性慢性腰背痛歼击机飞行员与无症状歼击机飞行员之间的表面肌电指标FER差异显著,屈曲时竖脊肌AEMG增高,伸直时竖脊肌AEMG降低,FER可以作为歼击机飞行员非特异性慢性腰背痛诊断及疗效评价的客观量化参考指标。     

在一对一空中格斗训练中的急性颈部疼痛的首次肌电图记录

前言 以前的研究表明,高+Gz力能引起战斗机飞行员的颈椎损伤。在研究一对一空中格斗训练中下肢、躯干和颈部肌肉牵张时,我们成功地记录了一例飞行中的颈部损伤。方法 在试验日,用携带式肌电图记录装置(ME3000P,Mega Eelectr.,芬兰)和表面电极两次记录6名飞行员的肌肉活动。结果用被测肌肉的最大随意收缩的百分比来表示。结果 一名飞行员     

战斗机高+Gz环境导致飞行员颈部损伤的原因及预防措施

目的 综述战斗机高+Gz环境导致飞行员颈部损伤的致伤原因、发生机制及预防措施,探讨采取综合性措施提升预防效果的发展前景.资料来源与选择国内外相关领域的研究论文与综述.资料引用国内外公开发表的论文和综述50篇.资料综合高性能战斗机的高+Gz值、高+Gz增长率特性给飞行员颈部健康造成极大的危害.近20多年来,众多学者针对高+Gz环境导致飞行员颈部损伤的机制和致伤原因进行了研究.在致伤阈值、头戴装备负荷、被动带飞、不良飞行姿态和反复暴露于高+Gz环境等致伤因素方面取得了较为一致的结果,提出的预防措施主要有加强颈部肌肉力量训练,研制防护装备及改善装备人机适配性,建立常规化的健康检查、康复训练、功能评价机制等.结论 战斗机飞行员在飞行职业生涯中不可避免地受到高+Gz环境的威胁,在当前单一预防措施效果不显著的情况下,积极采取综合性预防措施,并加强其预防效果的研究,对增强飞行员的飞行适应能力,提高飞行员健康水平将有极大的推动作用,并为高+Gz环境导致腰部损伤的预防工作提供借鉴经验. Abstract： Objective To review the reasons, mechanism of fighter aircraft high +Gz induced pilot's neck injuries and prevention methods, and to expect the integrative methods for enhancing prevention effects.Literature resource and selection Professional references which were published at home and abroad were cited.Literature quotation Fifty published papers and reviews were referred.Literature synthesis The characters of modern high-performance fighter aircraft which was described as high +Gz and the rapid onset rate acceleration induced serious harm to pilot's neck.Since more than 20 years, many researches on mechanism and the reasons of inducing neck injuries had conducted by scholars.They indicated the consensus in the factors of inducing neck injuries, including +Gz threshold, the load on pilot's head, passive effect on back seat, unsuitable head posture in flight and frequent exposure in high +Gz.The preventions were primarily focused on leaning upon cervical spine function evaluation and neck muscle strength training, developing protective equipment and improving man-machine adaptability of equipment.Conclusions In fighter pilot's career, it is unavoidable that he will be threatened by high +Gz environment.At present, it is important to adopt integrative preventions and emphasize effective research for increasing pilot's capability for adapting high + Gz environment and protecting himself.Also such experience will be useful in preventing pilot's waist injuries induced by high +Gz.     

飞行员头盔重心要求

目的 飞行员头盔重心要求,是飞行员头盔设计的最基本、最重要的参数之一,是关系到飞行员健康、安全和人-机效能充分发挥的重要指标.以头盔为平台安装显示、瞄准或夜视装置的综合头盔的迅速发展和应用,在增强头盔功能同时,也给飞行员健康、安全带来影响.装备研制急需制定头盔重心标准作为设计依据. 资料来源与选择该领域的标准、相关研究论文和综述. 资料引用国内外公开发表的标准、论著、论文和综述19篇. 资料综合对通过解剖法和CT法得到的人体头部重心进行比较分析和综合;对飞行头盔的重量、重心要求进行比较分析和综合. 结论 未查到政府组织发布的头盔重心标准,研究文献中提出的头盔重量、重心要求基本一致,但对头盔侧向重心的要求仍无定论,需开展研究.     

Relationships between surface-detected EMG signals and motor unit activation

INTRODUCTION: Surface-detected electromyographic (S-EMG) signals are used in exercise science to assess the extent of muscle activation, muscle fatigue, and neural activity during muscle contraction. However, the relationship has not been studied between S-EMG signal amplitude and motor unit activation at different muscle force levels. METHODS: S-EMG signals were measured from 76 healthy subjects during target force levels of 5, 10, 20, 30, and 50% of maximal voluntary contraction (MVC) of the knee extensors over 20-30 s. Mean absolute S-EMG amplitude, surface-detected motor unit action potential amplitude (S-MUAP), motor unit mean firing rate (mFR), and motor unit mean voltage, which is the product of S-MUAP amplitude and mFR, were assessed in the vastus medialis by using EMG signal-decomposition and spike-triggered averaging techniques. RESULTS: Motor unit mean voltage increased to the same degree as mean absolute S-EMG amplitude with increasing force, implying that motor unit size and firing rate explain the increase in mean absolute S-EMG amplitude with increasing force generation. In addition, mean absolute S-EMG amplitude increased linearly during the course of each 20-30 s contraction, with the slope being greater at higher force levels. A small change was observed in the shape of needle-detected motor unit action potentials during the contraction, but this change was not sufficient to explain the large change in mean absolute S-EMG amplitude during the contraction. CONCLUSION: Mean absolute S-EMG amplitude at different force levels and its changes during the course of a submaximal contraction are dependent on the number of motor units active, their size, and firing rates.     

Spinal MRI in fighter pilots and controls: a 13-year longitudinal study

INTRODUCTION: Although it is known that some degenerative changes occur in the spines of fighter pilots, it is not clear whether their frequent exposure to high acceleration is associated with premature development of such changes. This case-control study was designed help answer that question. METHODS: There were 12 Finnish Air Force pilot cadets and their controls who were examined using cervical and lumbar magnetic resonance imaging (MRI) before the pilots started fighter training (baseline) and 13 yr later (follow-up) when the pilots had accumulated a total of 1200 +/- 470 h in fighter aircraft. RESULTS: No statistical differences were found between groups with respect to the frequency of degenerative changes in either the cervical or lumbar spine. Cervical changes in pilots were for the most part observed in the lower part of the neck, while controls showed more variability as to location. In the lumbar region, pilots showed a non-significant tendency toward more changes in disks L4-S1, including changes in signal intensity, height, protrusions, and end plates. CONCLUSION: Occupational exposure to acceleration in fighter aircraft did not cause significant radiological changes in the spinal column during the first 13 yr of a fighter pilot's flying career. Assessments for the need of a fighter pilot's follow-up imaging should be based on clinical outcome, not on periodic imaging.     

人头颈部耐受高速气流吹袭限值

研究了人头颈部的气动特性的生物力学特性，提出人头颈部受到高速气流吹袭时，对气动阻力的耐受限值为２．４５２ｋＮ，对气劝和的耐受限值为１．３５８ｋＮ，对气动侧力的耐受限值为０．１６９ｋＮ，并给出了人头颈部高速气流吹袭的耐限曲线，不论乘员在何种姿势下弹射，作用在头颈部的气动力不超过以上数值才可免遭高速气流吹所的损伤。     

ATP economy of force maintenance in human tibialis anterior muscle

PURPOSE: The aim of this study was investigate ATP economy of force maintenance in the human tibialis anterior muscle during 60 s of anaerobic voluntary contraction at 50% of maximum voluntary contraction (MVC). METHODS: ATP turnover rate was evaluated using P magnetic resonance spectroscopy (P-MRS). The total volume of ankle dorsiflexor muscles was assessed by H magnetic resonance imaging (MRI) (H-MRI), and the fiber type composition of the tibialis anterior muscle was evaluated using histochemical analysis of muscle biopsies. RESULTS: The tibialis anterior muscle occupied 59.7 +/- 0.6% (mean +/- SEM) of the total ankle dorsiflexor muscle volume, which was 267 +/- 10 cm. Relative cross-sectional areas occupied by Type I, IIA, and IIB fibers in the tibialis anterior were 69.3 +/- 2.2, 27.4 +/- 2.76, and 3.2 +/- 1.0%, respectively. ATP economy of force maintenance did not change significantly during the 60-s contraction. It averaged at 4.81 +/- 0.42 N.s.micromol-1, and correlated with the relative cross-sectional area of the muscle occupied by Type I fiber (r = 0.73, P < 0.01). For the second half of the contraction, subjects dropping in force showed lower ATP economy compared with those maintaining the force (3.7 +/- 0.6 vs 5.3 +/- 0.6 N.s.micromol-1; P < 0.05). CONCLUSION: It is argued that the unchanged ATP economy of force maintenance during the voluntary contraction could be due to an increase in the ATP economy of contracting muscle fibers offsetting the effects of increased temperature and low ATP economy of Type II fibers. Mechanical interaction between motor units could also act to improve ATP economy of force maintenance.     

冲击性加速度对飞行员颈部的损伤与防护研究

目的 对军事飞行员冲击性加速度暴露引起的颈部损伤的国内外研究现状进行综述.资料来源与选择 该领域相关研究论文和综述.资料引用 国内外公开发表的论文和综述36篇.资料综合 主要对人颈椎的解剖学特点和在航空动力环境中的适应性改变、冲击性加速度对飞行员颈部损伤的发病率和发病形式、冲击性加速度对飞行员颈部损伤的力学分析和生理机制探讨、冲击性加速度对飞行员颈部损伤的研究方法以及冲击性加速度对飞行员颈部损伤的防护措施5个方面进行了介绍和讨论.结论 军事飞行员在冲击性加速度下的颈部损伤危险不可避免,因此需要充分重视和增强其防护措施的研究,以提高飞行员的职业健康水平、延长飞行寿命.     

Measuring mechanical properties of the vastus lateralis tendon-aponeurosis complex in vivo by ultrasound imaging

The mechanical properties of the human vastus lateralis (VL) tendon-aponeurosis complex were investigated in eight male subjects. Knee extensor force, knee joint angle, and corresponding longitudinal VL aponeurosis displacement were monitored synchronously during graded (10-s) maximal isometric knee extension contractions. Displacement observed during isometric conditions may be regarded as an expression of deformation in the tissues distal to the measurement site. Furthermore, aponeurosis displacement was measured during passive knee extension (90-75 degrees degrees ), and used to correct displacement values obtained during active contraction for joint angular motion. The passive trial yielded a highly linear relationship between aponeurosis displacement and joint angular motion (r2 = 0.998 +/- 0.002) with a mean correction factor of 0.41 +/- 0.10 mm/degree. Maximal knee extensor force was 5834 +/- 1341 N with a corresponding VL aponeurosis displacement of 12.7 +/- 2.5 mm, while correcting for joint angular motion reduced maximal displacement approximately 9% (to 11.6 +/- 2.5 mm, P < 0.005) (data presented as means +/- SD). Two separate graded contraction trials were performed, and no between-trial differences were observed in either maximal force or maximal displacement. Between trial coefficient of determination and CV for maximal force and maximal displacement were r2 = 0.97, CV = 2.9% and r2 = 0.92, CV = 4.6%, respectively, indicating intra-day reproducibility of measurements. These data demonstrate that when applying the newly established ultrasound-based method of investigating quadriceps connective tissue mechanical properties, maximal isometric contraction is inevitably associated with some joint angular motion that significantly influences the calculations.     

Contraction-induced potentiation of human motor unit discharge and surface EMG activity

In quadrupeds, an electrically induced, moderate to high intensity brief muscle contraction potentiates autogenetic excitation and leads to enhanced recruitment and/or tonic firing frequency of alpha-motor neurons. To determine if similar adaptations occur in humans, single motor units (SMUs) and surface electromyographic activity (EMG) were recorded from the right biceps brachii before and immediately after a 5-s 25% or 50% maximum voluntary contraction (MVC), while subjects held a handle (0-1% MVC) attached to a force transducer or maintained a 2% MVC for 30-60 s. Of 26 SMUs recorded, 15 increased, 4 decreased, and 7 showed no change in firing frequency (mean increase: 5 imp/s, P less than 0.01). Twelve SMUs had lower recruitment force thresholds after contraction. There was no significant treatment effect for the % MVC intensity. The postcontraction surface EMG power spectrum broadened, increased in amplitude, and contained a higher frequency component than the control contraction power spectrum. Changes in recruitment and/or frequency coding were reflected in the raw EMG records. Findings agree with previous reports in animals of contraction-induced potentiation of subsequent submaximal muscle contractions. Such acute adaptations in spinal neuromuscular pathways would function to optimize force output to a submaximal range of neural input frequencies.     

Comparison of cystourethrography and dynamic MRI in bladder neck descent

PURPOSE: The purpose of this work was to test whether there are statistically significant differences between dynamic MR and lateral cystourethrogram measurement results in patients with bladder neck descent. METHOD: Twenty-seven women (39-83 years old, mean 60.6 years old) with urinary incontinence and bladder neck descent were examined by dynamic MRI using a single shot fast spin echo sequence with half-Fourier data acquisition. Bladder neck position, angle of inclination of the urethral axis, posterior vesicourethral angle, and depth of cystoceles were measured at perineal contraction and at maximal pelvic strain. The nonparametric Wilcoxon test for paired values was used to analyze whether there were statistically significant differences between lateral cystourethrogram and dynamic MR measurement results. The Spearman correlation coefficient (rs) was calculated for all parameter pairs. RESULTS: Measurements at maximal pelvic strain showed the greatest levels of agreement between MRI and cystourethrography. The best results were attained for the cystocele measurements (p > 0.5, rs = 0.95). Bladder neck position showed the second best agreement; if MR measurements were corrected by 0.46 cm, no statistically significant difference (p > 0.2, rs = 0.92) was calculated. Measurements at perineal contraction tallied least, probably due to the different positions adopted during the two examinations. CONCLUSION: Measurement data on dynamic MRI for the bladder neck position and the extension of cystocele at maximal pelvic strain are comparable with lateral cystourethrogram data.