These numbers represent the rotation of a single elbow joint.

这些数字代表单个肘关节的旋转。

And so, we 3D-print three pieces with joints that represent the elbow joint and the wrist joint.

因此我们3D打印了三个由模拟的肘关节和踝关节连接的装置。

Finally, there are the diarthroses, which are fully movable, like your classic knee and elbow joints. They're mostly found in your limbs.

最后，还有可动关节，它们是完全可移动的，就像你经典的膝关节和肘关节。它们大多存在于你的四肢中。

The radius and ulna bones connect between the elbow joint and the wrist.

桡骨和尺骨连接在肘关节和腕关节之间。

And this here, like, lasso movement? That's circumduction — a combination of all five of those movements that allow the forearm to move in a circle while the elbow joint stays relatively stable.

关于套索运动，这是个环路运动——这五个运动的结合，让前臂绕着圆圈运动，而肘关节保持相对稳定。

When you see the apple, your brain's motor center activates the appropriate muscles, allowing you to reach out with your arm, grab it with your hand, bend your elbow joint, and bring it to your mouth.

当你看见苹果，大脑的运动部分激活合适的肌肉，使你伸出手臂，用手抓住它，弯曲手肘，把它送到你嘴中。