Sovelius Roope, Oksa Juha, Rintala Harri, Huhtala Heini, Siitonen Simo
Training Air Wing, Kauhava, Finland.
Aviat Space Environ Med. 2008 Feb;79(2):112-6. doi: 10.3357/asem.2130.2008.
The helmet-mounted equipment worn by military pilots increases the weight of the helmet system and shifts its center of gravity, increasing the loads on neck structures, especially during acceleration. The aim of this study was to determine neck muscle strain with different head-loads during trampoline-induced G loads (0 to +4 G).
Under three conditions [no helmet, helmet, helmet with night vision goggles (NVG)], 14 subjects performed trampoline exercises including basic, hand-and-knee, and back bouncing. EMG activity was measured for the sternocleidomastoid (SCM), cervical erector spinae (CES), trapezoid (TRA), and thoracic erector spinae (TES) muscles. Muscle strain was determined as a percentage of maximal voluntary contraction (%MVC).
For the three exercises combined, the following significant changes were found: compared to control, the helmet increased muscle strain by 18%, 28%, and 18% in the SCM, CES, and TRA, respectively; NVG produced a further increase of 11% in the SCM and 6% in the CES. During back bouncing, the helmet increased muscle strain by 14% in the SCM and 19% in the CES, and NVG further increased this strain by 14% in the SCM. Hand-and-knee bouncing loaded extensors: the helmet caused increases of 46% in the CES and 29% in the TES, while NVG produced a further 13% increase in CES activation.
Helmet weight alone had a large effect on muscular workload. The additional frontal weight of the NVG caused a further increase in the activity of cervical muscles that were already subjected to high strain.
军事飞行员佩戴的头盔-mounted设备增加了头盔系统的重量并使其重心发生偏移，增加了颈部结构上的负荷，尤其是在加速过程中。本研究的目的是确定在蹦床诱导的G负荷（0至+4G）期间不同头部负荷下的颈部肌肉应变。
在三种条件下[无头盔、头盔、带夜视镜（NVG）的头盔]，14名受试者进行了蹦床练习，包括基本蹦跳、手膝蹦跳和背部反弹。测量了胸锁乳突肌（SCM）、颈竖脊肌（CES）、斜方肌（TRA）和胸段竖脊肌（TES）的肌电图活动。肌肉应变以最大自主收缩的百分比（%MVC）来确定。
对于这三种练习的综合结果，发现了以下显著变化：与对照组相比，头盔使SCM、CES和TRA的肌肉应变分别增加了18%、28%和18%；NVG使SCM的肌肉应变进一步增加了11%，CES增加了6%。在背部反弹期间，头盔使SCM的肌肉应变增加了14%，CES增加了19%，NVG使SCM的这种应变进一步增加了14%。手膝蹦跳使伸肌负荷增加：头盔使CES增加了46%，TES增加了29%，而NVG使CES的激活进一步增加了13%。
仅头盔重量就对肌肉工作量有很大影响。NVG额外的前部重量导致已经承受高应变的颈部肌肉活动进一步增加。
