And we can see that, you know, chimpanzees and early hominins had a small chimp-like gluteus maximus.

我们可以看到，黑猩猩和早期人类有一个像黑猩猩一样的小臀大肌。

So the gluteus maximus plays a very important role when you're— when you're running, and turns out to barely be active when you're walking.

因此，当你跑步时，臀大肌起着非常重要的作用，而当你走路时，臀大肌几乎不活跃。

And so your gluteus maximus fires just before your body's about to—your trunk is about to pitch forward and make you hit your nose on the ground, and it helps pull your trunk backward.

因此，在你的身体即将前倾并让你的鼻子撞到地面之前，你的臀大肌就会启动，这有助于将你的躯干向后拉。

Each one of your different skeletal muscles — like your biceps brachii, or vastus lateralis or gluteus maximus — is technically its own organ, made up mostly of muscle tissue, but also of connective tissue, blood vessels, and nerve fibers.

你的每一块不同的骨骼肌——比如肱二头肌、股外侧肌或臀大肌——严格来说都是自己的器官，主要由肌肉组织组成，但也由结缔组织、血管和神经纤维组成。

And the other time the gluteus maximus fires is when your leg is swinging forward when you're in the air, and it helps decelerate the leg so that you bring your leg down onto the ground.

另一次，当你在空中时，当你的腿向前摆动时，臀大肌就会发火，这有助于使腿减速，以便你将腿落到地面上。

And it turns out that very nicely we can see when the gluteus maximus got big in human evolution because its upper portion, the portion that's really important for this function, leaves a trace on the pelvis, on the bone.

事实证明，我们可以很好地看到臀大肌在人类进化过程中何时变大，因为它的上部，即对该功能非常重要的部分，在骨盆和骨骼上留下了痕迹。