侧头鞍沟
lateral glabellar furrows
定向钻头侧向分力
directional bit side force component
腓肠肌内侧头
Gas-trocnemius muscle
gastrocnemius medial head
腓肠肌内侧头肌瓣
Medial heal of gastrocnemius
肱三头肌外侧头
lateral head of triceps brachii
井斜钻头侧向分力
inclinational bit side force component