利用体表肌电评价飞行员头颈部防护装置防护效果的研究

目的 通过观察受试者使用飞行员头颈部防护装置(neck protection device,NPD)时颈部表面肌电信号(surface electromyographic signal,sEMG)变化探讨该装置的防护效果.方法 15名男性志愿者,在不戴装备、仅戴保护头盔、同时戴保护头盔和飞行员头颈部防护装置3种情况下,分别测量颈椎前屈0°、10°、20°、30°、40°、50°和最大限度时的sEMG;并通过在头盔下颏带上悬挂1个2.5 kg配重的方式模拟+Gz过载时颈部的受力情况,记录此时在有、无颈部防护装置情况下颈部前屈到最大限度时的sEMG;计算振幅均方根值(root mean square,RMS).结果 受试者颈部在不戴任何装备及仅戴飞行保护头盔两种情况下做前屈时,不同前屈角度时的体表肌电值差异有统计学意义(F=160.454、129.563,P＜0.01).与头部处于中和位(颈前屈0°)时相比,受试者不戴装备时颈前屈至30°时的sEMG达最大值(5.99±1.99)mV,戴飞行保护头盔颈前屈至40°时的肌电信号达最大值(10.14±3.80)mV.戴飞行保护头盔后颈部前屈20°～50°时的sEMG大于不戴装备时,且差异有统计学意义(P＜0.05).头盔下悬挂配重后sEMG进一步增大.在同时戴飞行保护头盔及NPD后,无论是颈前屈至各种角度还是增加配重后前屈至50°,颈肌sEMG与不戴装备相比差异均无统计学意义.结论 受试者在戴飞行保护头盔及悬挂配重时作颈前屈会导致颈部肌电活动强度显著增强,而NPD可显著减轻两种情况下时的颈肌负荷.Abstract：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.

Protection effect of a neck protection device evaluated by surface electromyographic signal

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.