Neck strength and EMG activity in fighter pilots with episodic neck pain

INTRODUCTION: Neck pain is common in fighter pilots due to repeated exposure to high +Gz loads, but studies comparing neck function in symptomatic and healthy fighter pilots are lacking. This study compared neck strength and EMG activity during maximal isometric contractions in a sitting position in the sagittal and coronal planes in neck pain (SP), asymptomatic fighter pilots (AP), and healthy, male, non-pilot subjects (NPS). METHODS: There were 9 SP, 10 AP, and 8 NPS, all males, who performed maximal isometric neck contractions on a specific dynamometer. Surface EMG activity was recorded bilaterally over the sternocleidomastoid and paraspinal muscles. EMG amplitude during side bending was normalized to that measured in the sagittal plane. RESULTS: SP exhibited lower side-bending strength than AP (17-19%, P < 0.05). In addition, SP and NPS exhibited lower left side-bending-to-extension torque ratios (20% and 14%, respectively, P < 0.05) than AP. Similar activation level of neck flexors and extensors during side bending was found in SP and AP, whereas EMG activity of the extensors was higher than the flexors in NPS (+48%, P < 0.05). In addition, antagonistic EMG activity was higher in AP compared to NPS (26% vs. 41%, respectively, P < 0.05). CONCLUSION: Our results suggest altered muscle function in SP compared with AP in the coronal but not in the sagittal plane. Further, AP appeared to be more efficient in the coronal plane with reference to neck extension than NPS, suggesting that some adaptations occurred due to flight exposure. These findings may have clinical implications for the management and the follow-up of neck pain in fighter pilots.     

Spinal X-ray screening of high performance fighter pilots.

Neck pain and neck injury are common complaints among military aviators flying high performance (HPF) aircraft. Since all candidates for military flying training with the Royal Norwegian Air Force have to meet HPF medical standards, medical selection procedures include a radiological examination of the spine. Nine films of the vertebral column are made with emphasis put on cervical structures. Among 232 applicants, 527 deviations from normal conditions were described--anomalies, degenerative changes and deviations of posture--which average 2.27 diagnoses per spine X-rayed. Of the candidates, 80 were considered entirely within normal limits; 20 were rejected due to the roentgen findings; and five candidates were excluded on final evaluation, their radiological diagnoses contributing to the decision. Although most changes are slight, many significant conditions are demonstrated among young healthy individuals. Since the population is highly selected, the figures we present may be minimum numbers in a western industralized society.     

Chiari-I malformation in two fighter pilots

This report describes two cases of Chiari Malformation Type I (Chiari-I) in fighter pilots of the Turkish Air Force. Chiari-I is a congenital malformation characterized by herniation of cerebellar tonsils through the foramen magnum. Patients have symptoms and signs related to dysfunction of the brainstem, spinal cord, and cerebellum. They generally are symptomatic in the earlier years of life. However, asymptomatic cases can eventually become symptomatic in later years. Symptoms can be provoked by increasing intracranial pressure (Valsalva or straining). We report on two pilots with Chiari-I malformation who had no symptoms or signs in their daily activities. Furthermore, these pilots had successfully completed physiological training, including centrifuge training, without any symptoms. However, they suffered from headache, neck spasms, and/or disequilibrium under +Gz during flight training sorties. The clinical presentation, diagnosis, treatment, possibility of acquired cases, and aeromedical disposition of Chiari malformations are discussed.     

战斗机飞行员脑血流动力学的研究

目的 探讨战斗机飞行员脑血流动力学的特点.方法 试验对象分为3组：战斗机飞行员组（40名）、运输机飞行员组（30名）和健康对照组（30名）,分别用2 MHz多普勒探头检测颅内各动脉的血流速度及搏动指数.结果 战斗机飞行员组与其他两组比较,颅内动脉各期血流速度呈对称性增快,差异均有显著性意义（P＜0.01）,以大脑中动脉、大脑后动脉、椎动脉、基底动脉和眼动脉血流速度增快明显.搏动指数虽有升高,但无统计学意义.运输机飞行员组与健康对照组相比,各期血流速度差异不显著.结论 战斗机飞行员颅脑动脉高血流流速是一种代偿性生理变化,在飞行鉴定时应引起重视.     

歼击机飞行人员屈光不正构成变化的研究

目的 探讨歼击机飞行员和飞行人员在不同年代因屈光不正住院的屈光分布及患病的危险因素.方法 对159例因屈光不正住院的飞行人员和66例歼击机飞行员进行回顾性临床分析.对各种屈光类型不同年代的构成进行比较.结果 1963～2007年飞行人员近视类屈光不正患病眼数各年代分别为7、18、23、29、39,分别占同年代屈光不正数的11.87%、26.87%、36.51%、63.04%、81.25%,趋势X2值为68.16(P＜0.01);远视类屈光不正分别为40、40、34、10、3眼,分别占同年代屈光不正的67.8%、59.7%、53.97%、21.74%、6.25%,趋势X2值为59.49(P＜0.01).歼击机飞行员近视类屈光不正不同年代患病眼数分别为2,7、17、8、14眼,分别占同年代屈光不正的13.33%、23.33%、42.5%、40%、63.6%,趋势X2值为13.75(P＜0.01),呈增加趋势.结论 随着年代的推移,远视类屈光不正的发病呈下降趋势,近视类屈光不正则呈增加趋势.飞行人员迟发性近视应予重视.     

高性能战斗机飞行员医学选拔

随着高科技的不断发展和现代战争的需要 ,高性能战斗机作为决定战争胜负的主要手段之一已广泛出现于现代战场。为了使目前我军歼击机飞行员适应高性能战斗机的要求 ,我们对经飞行部队航医初步选拔的歼击机飞行员进行全面的疾病回顾和系统检查 ,选拔出合格的高性能战斗机飞行员 ,现报告如下。一、对象与方法1.对象 :所选飞行员 ,男性 ,均为歼、强击机飞行员 ,平均年龄 32 .6岁 ,平均飞行时间 1190 h。2 .医学选拔方法 :采取系统检查和综合评价的方法。1追踪病史 :从飞行员中详细询问既往患病史或不适主诉 ;从相关人员 ,包括同事、航医等详细…     

歼击机飞行员颈椎X线表现调查

目的　探讨高 G加速度对飞行员颈椎可能产生的影响及其临床意义。　方法　对一组正常歼击机飞行员的颈椎 X线摄片分析 ,同样对一组正常地面人员的摄片 ,就常见的异常 X线征像结合临床情况进行讨论分析比较。　结果　飞行员组颈椎“切凹征”的出现率较对照组明显增高 ;颈曲变直、反向或侧弯程度都比对照组要显著 ;颈椎椎间隙狭窄情况两组无明显差异。对照组颈椎既往症状发生率显著增高于飞行员组。　结论　加速度负荷可能是加速颈椎退变主要因素之一 ,但 X线所示的颈椎退行性改变并不一定意味着临床症状的出现 ;飞行员常规保持体育运动对颈椎临床症状的预防具有重要的临床意义。     

战斗机飞行员长时血压变异性分析

目的探讨飞行员动态血压（ＡＢＰ）昼夜分布特征及其变异范围，为高性能战斗机飞行员心血管体能选拔提供依据。方法对６０名男性战斗机飞行员进行２４小时动态血压监测与不同时间锁定方法学分析比较。结果①与正常人群一样，飞行员２４ｈ－ＡＢＰ存在明显的昼夜循环节奏变化，即白天血压高，夜间血压低，呈现一种典型的“勺型”分布。但血压平均水平较一般正常人群低；②飞行员２４ｈ血压变异（ＢＰＶ）显著大于白昼ＢＰＶ，白昼ＢＰＶ显著大于夜间ＢＰＶ；③不同时间锁定窗口所得夜间ＢＰＶ参值及血压昼夜差值之间存在明显差异。结论２４ｈ－ＢＰＶ分析能为高性能战斗机飞行员心血管调节机能提供重要信息     

战斗机飞行员颈椎退变研究

目的 了解战斗机飞行人员颈椎退变情况。方法对5年前作过MRI检查的战斗机飞行员（甲组,平均年龄47岁,平均累计飞行时间2100h,乙组,平均年龄27岁,平均累计飞行时间830h）。和无飞行经验年龄相仿的对照组人员（丙组）进行复查。结果与5年前MRI结果比较,每组的椎间盘突出数增加,但丙组的骨赘、老飞行员的椎管狭窄数明显增加。与5年前比较,老飞行人员与丙组间的MRI差别降低。结论战斗机飞行员的椎间盘退行性病变的发展可能较早。但是,随着年龄的增加,与对照组的差别逐渐缩小。     

MRI cervical spine findings in asymptomatic fighter pilots

MRI of the cervical spine for evaluation concerning degenerative lesions was performed on asymptomatic experienced military high performance aircraft pilots (mean age 42 yr with mean accumulated flying time of 2600 h), and for comparison on age-matched controls without military flying experience. Young military high performance aircraft pilots (mean age 23 yr with 220 h of flying per person) were also examined. There were significantly more osteophytes, disk protrusions, compressions of the spinal cord and foraminal stenoses in the experienced pilots than in the age-matched controls. Low frequency of low grade degenerative lesions was found in the young and inexperienced pilots.     

Prevalence of right-to-left shunts in active fighter pilots

BACKGROUND: Patent foramen ovale (PFO) is a risk factor for cerebrovascular accidents and provides a potential mechanism for paradoxical systemic embolization of venous gas bubbles produced after altitude decompression. The objective of the study is to describe the prevalence of PFO and of possible subsequent brain lesions in active military fighter pilots. METHODS: A sample of 52 healthy active fighter pilots was assessed with transcranial Doppler sonography, transesophageal echocardiography, and cranial MRI. RESULTS: Significant right to left shunting occurred in 17% (9/52; 95% CI 8.7% to 30.8%); all shunts were due to a PFO. Cranial MRI was normal in each case. CONCLUSION: In this sample, prevalence of PFO lies within the expected range. There is no evidence that military flying in pilots who carry PFOs leads to brain damage. Screening for PFO is not recommended.     

Neck strength and myoelectric fatigue in fighter and helicopter pilots with a history of neck pain

INTRODUCTION: Flight-induced neck pain at high Gz loads or during sustained rotary-wing missions may be caused by limitations in neck muscle function. A better understanding of the contributing factors of excessive external load and internal neck-stabilizing mechanisms would improve the ability to prevent and treat such pain. The aim of this single-blinded cross-sectional study was to evaluate neck neuromuscular function in fighter and helicopter pilots who suffered from frequent neck pain. METHODS: Subjects with pain were 16 fighter pilots (FP-P) and 15 helicopter pilots (HP-P) with frequent neck pain episodes who were compared with pain-free controls (FP-C and HP-C). In all groups, neck extensor and flexor muscles were studied by measuring 1) the strength of maximum voluntary contraction (MVC), and 2) fatigue due to a submaximal isometric contraction. The decline (slope) of the electromyogram (EMG) median frequency power spectra was used as an index of fatigue, while initial median frequency (fi) was taken from the intercept of the regression line. RESULTS: Two-way analysis of variance (ANOVA) revealed interaction effects for extensor MVC. Post hoc testing showed that FP-P had significantly lower extensor MVC (p = 0.03) than FP-C, while there was no such difference for the HP-P vs. HP-C or between the two control groups. There were no significant effects for MVC-balance (flexors/extensors); nor were there any fi or extensor EMG-slope effects. However, there were interaction effects for flexor EMG-slopes: HP-P showed lower slopes than did HP-C (p = 0.02). CONCLUSIONS: To protect and stabilize the head and neck in high Gz environments, higher neck muscle strength is needed; less muscle strength in FP-P may cause further pain and perhaps reduced mission effectiveness. Less localized steep slopes for HP-P might reflect impaired muscle functioning. Specific preventive and clinical attention may be warranted for different types of pilot.     

歼击机飞行员住院疾病谱分析

目的 研究歼击机飞行员住院疾病谱的变化规律. 方法 对医院所收治的1200名歼5、歼6和歼7飞行员的疾病谱进行对比分析. 结果 ①排前10位的病症为空中晕厥、腰椎病、慢性胃炎、加速度耐力不良、地面晕厥、航空性中耳炎、泌尿系结石、眩晕、神经衰弱和颈椎病.②排在歼7飞行员前10位的病症为腰椎病、脂肪肝、慢性胃炎、噪声性聋、高脂血症、右束支传导阻滞、高血压、严重飞行错觉、航空性中耳炎和肝内胆管结石. 结论 歼5、6、7三型歼击机飞行员住院疾病谱有所不同,与歼5、6相比歼7飞行员有些病症呈下降趋势,有些病症呈上升趋势,对其原因进行分析有助于提高航卫保障质量.     

高性能战斗机飞行员抗G知识调查

为了解我军高性能战斗机飞行员对飞机载荷特点理解掌握程度，以便更有针对性地对他们进行航空生理教育和专项训练，正确使用抗G防护装备，提高抗G动作的效果，我们进行了抗G知识的问卷调查。     

歼击机飞行员颈椎X线平片分析

为了解飞行对颈椎的影响，我们自2001年5月至2003年5月，从健康疗养的歼击机飞行员中进行了颈椎X线摄片检查，并与地面无症状人群对照比较，结果如下。     

Dark focus measured in Navy jet tactical fighter pilots

Visual accommodation was measured with the laser-Badal optometer in 98 U.S. Navy fighter pilots who were in a dark environment without visual stimuli. The average dark focus of the pilots was 0.25 diopters of myopia; 40% were either emmetropic or hyperopic in the dark. Only 4% had as much dark myopia as 50% of a sample of 220 college students. Although the jet fighter pilots, as a population, differed from college students in terms of dark focus, it remains to be determined whether the remarkable dark focus of the pilots was a function of training or selection. The dark focus measurements of the pilots were compared to their mean night carrier landing scores and their mean target detection slant range scores--the distance at which an adversary aircraft is first sighted during an air combat maneuver training engagement. Neither the night carrier landing scores nor the target detection slant range scores correlated significantly with dark focus measurements.     

Proteinuria in fighter pilots after high +Gz exposure

Exposure to high gravitational forces acting along the body axis towards the feet (+Gz) causes considerable strain on several organ systems, including the kidneys. During +Gz tolerance studies without anti-G suits, significant amounts of protein and hyaline casts were found in 17 of 20 fighter pilots after centrifugation. The G load alternated between 3.5 and 5.5 G. Mean time in the centrifuge was 15 min. For comparison we examined another group of 19 fighter pilots after air combat maneuver training with anti-G suits. None showed proteinuria. The proteinuria most likely indicates a severely depressed renal blood flow during centrifugation.