Objective To evaluate the protection effect of a neck protection device (NPD) by analyzing neck muscle surface electromyographic signal (sEMG) for pilot.Methods Fifteen male subjects were tested under three conditions that were with no equipment, wearing helmet, and wearing helmet plus NPD respectively.At first, subjects flexed their necks from 10° to ultimate degree.Then subjects performed same maneuvers with helmet or with helmet and NPD when a 2.5 kg extra weight was appended on chin belt of helmet for simulating +Gz load.Neck sEMG was measured in all tests and root mean square (RMS) of amplitude was calculated.Results When flexing without equipment or only with helmet subjects' neck sEMG showed significant difference (F-160.454, 129.563, P＜0.01).For the subjects without any equipment, their neck sEMG appeared peak (5.99±1.99) mV as flexing to 30° when referenced to neutral position of head.But for the subjects with helmet the neck sEMG peak appeared at 40° flexing (10.14±3.80) mV.Within the 20° to 50° flexing range, helmet resulted in significantly higher neck sEMG comparing to no load condition (P＜0.05).Extra weight drove the incensement of neck tension.However, there was no significant difference in neck sEMG activity when flexed to any degree with helmet and NPD or to 50° with the extra weight.Conclusions Neck sEMG significantly increases when subject flexed with helmet or with an extra weight.The NPD could abate subject's tension on neck when wearing helmet.

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.

Objective To evaluate the protection effect of a neck protection device (NPD) by analyzing neck muscle surface electromyographic signal (sEMG) for pilot.Methods Fifteen male subjects were tested under three conditions that were with no equipment, wearing helmet, and wearing helmet plus NPD respectively.At first, subjects flexed their necks from 10° to ultimate degree.Then subjects performed same maneuvers with helmet or with helmet and NPD when a 2.5 kg extra weight was appended on chin belt of helmet for simulating +Gz load.Neck sEMG was measured in all tests and root mean square (RMS) of amplitude was calculated.Results When flexing without equipment or only with helmet subjects' neck sEMG showed significant difference (F-160.454, 129.563, P＜0.01).For the subjects without any equipment, their neck sEMG appeared peak (5.99±1.99) mV as flexing to 30° when referenced to neutral position of head.But for the subjects with helmet the neck sEMG peak appeared at 40° flexing (10.14±3.80) mV.Within the 20° to 50° flexing range, helmet resulted in significantly higher neck sEMG comparing to no load condition (P＜0.05).Extra weight drove the incensement of neck tension.However, there was no significant difference in neck sEMG activity when flexed to any degree with helmet and NPD or to 50° with the extra weight.Conclusions Neck sEMG significantly increases when subject flexed with helmet or with an extra weight.The NPD could abate subject's tension on neck when wearing helmet.

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.