抄録
Fighter pilots are exposed to high sustained Gz force during air-to-air combat maneuvering. Muscle
activities are very important because of its main role in pilot toleration of high Gz forces.
The purpose of this study was to evaluate the differences of several muscle activities during anti-G
straining maneuver (AGSM) and measure electromyographic(EMG) activities of experienced pilots
during acceleration training ［GOR (Gradual Onset Rate) and ROR (Rapid Onset Rate) profiles］.
Subjects are thirty six experienced pilots. Their mean age (±SD)was 25.4±2.3yr, mean height
was 173.3±6.3cm, and mean weight was 69.7±9.9kg.
They were exposed to two training profiles (GOR and ROR), with Gz level from 4.0Gz to 7.0Gz
and onset rate from 0.26 to 0.55Gz/sec. (GOR, range of sustained time were 15sec. to 30sec.) and
onset rate of 2.0Gz/sec. (ROR, range of sustained time were 5sec. to 20sec.). During the training, G
suit was fitted and AGSM was performed .
In this study, EMG was measured from m. vastus lateralis (VL), m. rectus abdominis (RA), m.
sternocleidomastoideus (SCM) and m. elector spinae (ES) of each subject. The mean and peak
muscular strain for each muscle was calculated as the percentage of maximal voluntary contraction
(%MVC). The EMG were measured using a portable four channel EMG device (ME3000P, Mega
Electronics Ltd., Kuopio, Finland). Before Gz exposure, the maximal voluntary contraction (MVC) of
each muscle was measured.
