Neck pain in F-16 vs. Typhoon fighter pilots.

INTRODUCTION: In jet pilots, the neck is stressed by dynamic loading and there is growing concern about possible neck damage in pilots of new agile aircraft. Jet pilots often report neck pain after flight so intense that their operational capability may be affected. However, there is no clear evidence of structural damage related to the operational exposure. METHODS: We compared 35 F-16 pilots with 35 age-matched Eurofighter Typhoon pilots. All subjects completed an anonymous questionnaire on their flight activity and neck pain. RESULTS: The incidence of neck pain in the F-16 group was 48.6% compared with 5.7% of the Typhoon group, significantly higher. In F-16 pilots, there was a significant association between neck pain and age over 30 yr, total flight hours, and flight hours exceeding 600. DISCUSSION: Our findings suggest that the risk of neck pain after flight is higher among F-16 pilots compared with Typhoon pilots. This could be due to several reasons, including the backward reclined seat of the F-16, which exposes the neck to the load in an unfavorable posture while moving the head during maneuvers at sustained high-G.

Rehabilitation from airsickness in military pilots: long-term treatment effectiveness.

BACKGROUND: Airsickness (AS) still represents a major issue in aviation medicine and affects many student pilots and aircrew members. This study aimed at producing an update of the Italian Air Force rehabilitation program for AS, including data on a prolonged follow-up (> 8 yr). METHODS: Data from 20 military pilots with a past history of rehabilitation for incapacitating AS were compared to those of 65 normal controls. All individuals from both samples were categorized as dropouts or successfully employed in fast jets, multiengine air carriers, or helicopters. All AS individuals were analyzed before and after their treatment with the Coriolis Stress test (CST). RESULTS: The AS sample showed similar results with respect to the control group, with the same incidence of dropouts (15% vs. 14%) and destination to rotary wing flight lines (15% vs. 17%). All dropouts were observed within the first year after rehabilitation. A statistically non-significant trend of being employed in transport aircraft (50% of individuals vs. 34% in the control group) rather than in fast jets (20% vs. 35%) was observed in the AS sample. DISCUSSION: Within the AS sample, the rehabilitation protocol had a success rate of 85%. The effects of rehabilitation were long lasting (mean follow up: 8.3 +/- 2.5 yr). Moreover, the flight career of AS treated individuals did not significantly differ from controls. The pretreatment CST was helpful in calibrating the initial intensity and duration of the nauseogenic stimulation, while it was useless as a post-treatment analysis of the outcome from training.

Gender effects on mental rotation in pilots vs. nonpilots.

INTRODUCTION: Mental rotation ability has an important role in human navigation and, together with other cognitive abilities such as processing speed, working memory, and attention, is crucial for aircraft navigation. In the human performance literature, mental rotation tasks have consistently yielded reports of gender differences favoring men. The aim of this study was to compare the gender difference measured in a specialized population of aviators vs. a matched population of nonpilots. METHODS: : Studied were 41 pilots (20 men and 21 women) and 38 nonpilots (20 men and 18 women) matched for age and education. Pilots were stratified for flying hours. Participants performed a mental rotation task (MRT) in which accuracy and response time were recorded, and also completed sense-of-direction (SOD) and spatial cognitive styles self-evaluation scales. RESULTS: Men had significantly smaller response time in the MRT (men 279.6 +/- 147.0 s, women 401.6 +/- 361.3) and greater SOD (men's score 49.1 +/- 8.6, women's score 46.6 +/- 7.8), but these differences were absent among pilots. A positive relationship was also identified between pilots' response times and their flight hours. CONCLUSION: These data suggest that the effect of gender on the speed of cognitive spatial processing is absent in a population with aviation experience. Gender effects may be associated with a low spatial cognitive style, whereas in groups such as aviators, who are expected to have high spatial cognitive style, other factors such as experience may come into play.

Assessment of gravitational stress on heart rate variability during maneuvers on high performance jet flights.

The Push-Pull Effect (PPE) is a physiological phenomenon defined as a reduction of +Gz tolerance induced by a previous exposure to a -Gz acceleration, that may lead to loss of consciousness. Aim of this study was to evaluate, for the first time, the cardiac rhythm changes associated with PPE during real flights. Data were collected in 3 pilots during flights on the Aermacchi MB- 339-CD aircraft. In each flight, lasting about 60 minutes, ECG, respiration and 3D accelerations were recorded by a new smart garment (the MagIC System). The flight protocol included a maneuver eliciting a reference +5Gz acceleration for 15 seconds (Ref+5G), followed, after a while, by a push-pull maneuver with a profile characterized by a 5-s acceleration at -1Gz (PP-1G) and, with a 1G/s onset, by 15 seconds at +5Gz (PP+5G), so to induce the push-pull gravitational stress. From each ECG recording, a beat-by-beat RR Interval (RRI) series was derived. RRI mean, standard deviation (SDNN) and the RRI Root Mean Square of Successive Difference (RMSSD) were estimated in each pilot during the Ref+5G and the PP+5G maneuvers. As compared with Ref+5G, all pilots displayed significant reductions in RRI mean, SDNN and RMSSD during PP+5G. These findings are compatible with a PP-induced enhancement in the sympathetic drive to the heart -as shown by the reduction in RRI mean and SDNN- and a concomitant deactivation of the parasympathetic control as shown by the reduction in RMSSD.

[Syncope in the hyperbaric environment]. / Sincope in ambiente iperbarico.

The ever larger number of individuals who practice breath-hold diving suggests an increased need to understand the potential consequences of these sports activities. In this setting, syncope in hyperbaric environment represents a peculiar condition that goes beyond the common classifications of syncope. The pathophysiological mechanisms that underlie its etiology are complex and involve several reflexes that are triggered in these circumstances. Prevention of syncope in apnea divers requires a deep understanding of its pathophysiological mechanisms with inherent preventive measures on behalf of both cardiologists and sports cardiologists.

[Cardiovascular consequences of aerobic maneuvers]. / Le modificazioni cardiovascolari nel volo acrobatico.

Gravitational (G) stress during aerobatics flights, both military and civilian, can suddenly incapacitate pilots in agile and supermaneuverable aircrafts. High +Gz stress, up to +9Gz, has two different physiological consequences: the first is the drop in head-level blood pressure that is proportional to the G load; the other, slightly delayed, is the blood pooling in the lower part of the body and the abdomen. This blood shift results in a decreased return of venous blood to the heart, decreased cardiac output, and decreased blood pressure, leading to a likely loss of consciousness. The natural countermeasure against the effects of high G stress is the baroreceptor reflex. The human physiological tolerance to the gravito-inertial forces developed in flight operations can be increased by physiological and technological means.

Effects of airsickness in male and female student pilots: adaptation rates and 4-year outcomes.

INTRODUCTION: Airsickness (AS) often affects aircrew members, especially at the beginning of their flight careers. In this study the AS incidence in 376 Italian Air Force student pilots (336 men and 40 women) was investigated during their initial flight activity. METHODS: The study was separated into two parts. In part 1, the AS incidence was analyzed in the whole sample to determine the overall characteristics of AS and the hypothetical differences between men and women during the first flight certification (Basic). Part 2 analyzed a subpopulation of 102 individuals (86 men, 16 women) over 4 subsequent years throughout the first 4 flight certifications (for a total of about 60 flight hours). In all cases, AS was evaluated according to the number of flight missions affected by vomiting episodes. RESULTS: The overall AS incidence during Basic was 34.8%, without significant gender differences. However, within AS individuals, a significantly higher percentage of women were slow adaptors (12.5% of the whole female sample vs. 3.3% in men). AS overall affected the likelihood of reaching Basic certification, but this was not significantly related to the number of AS episodes. The 1-yr interval between two subsequent flight certifications caused a loss of adaptation to the flight environment in most cases. DISCUSSION: The absolute incidence of AS in our study resulted within the expected range, without significant differences between men and women. In a minor number of individuals (11 out of 336 men and 5 out of 40 women) a slow capability of adaptation to AS was observed. Such a finding was statistically more prevalent in women. In contrast to previous literature data, when prolonged interruptions from flight activity are planned, the retention of adaptation in our study did not play a significant role in avoiding future episodes of AS.

The effect of cinnarizine and cocculus indicus on simulator sickness.

Pensacola Simulator Sickness Questionnaire (SSQ) is a valuable method to analyse symptoms evoked by exposure to a flight simulator environment that can also be adopted to evaluate the effectiveness of preventive tools, aiming at reducing simulator sickness (SS). In this study we analysed SSQ data in subjects undergoing a standard ground based spatial disorientation training inside a flight simulator, in order to evaluate the SS prevention obtained with two different pharmacological tools. Twelve males volunteers participated to an experimental design based on a double-blind, balanced administration of either 30 mg cinnarizine (CIN), or Cocculus Indicus 6CH (COC), or placebo (PLC) before one trial of about one hour spent inside a spatial disorientation trainer. All subjects underwent the three different conditions (CIN, COC, PLC) during 3 non-consecutive days separated by at least 2 weeks. During each experimental day, all subjects filled in SSQ. In addition, both postural instability (with the use of a static stabilometric platform), and sleepiness symptoms were evaluated. All the tests were performed before and after the simulated flight, at different times, in one-and-half-hour intervals. Results indicated a strong increase of sickness after flight simulation that linearly decreased, showing pre-simulator scores after 1.30 hours. In contrast to both PLC and COC, CIN showed significant side effects immediately following flight simulation, with no benefit at the simultaneous SSQ scores. Globally, no highly significant differences between COC and PLC were observed, although a minor degree of postural instability could be detected after COC administration. As far as the present exposure to a simulator environment is concerned, none of the pharmacological tools administered in this study resulted effective in reducing SS symptoms as detected by the SSQ. Moreover, CIN significantly increased sleepiness and postural instability in most subjects.