Alternate Picking is the general term for any picking motion that moves back and forth while playing a note with each change in direction.
交替拨弦是任何拨弦动作的总称，指的是在弹奏音符时随着方向的每次变化而来回移动的任何拨弦动作。

When it comes to playing a sequence of notes on an individual string, alternate picking is the most mechanically efficient way to do it. And because playing more than one note on a string is so fundamental to playing guitar, almost all guitarists who use a pick eventually learn one or more alternate picking techniques.
当涉及到在单个琴弦上弹奏一系列音符时，交替拨弦是机械上最有效的方法。而且因为在琴弦上弹奏多个音符对于弹吉他来说非常基础，所以几乎所有使用拨片的吉他手最终都会学会一种或多种交替的拨弦技巧。

Down And Up

The two directions of an alternate picking motion are arbitrarily referred to as the downstroke and the upstroke. This is true even when the motion itself doesn’t move strictly down and up. In fact, many alternate picking motions actually trace an arc or semicircle rather than a straight line, even if we don’t always think of them that way.
交替拨弦动作的两个方向被任意地称为下冲程和上冲程。即使运动本身并不严格地向下和向上移动，也是如此。事实上，许多交替的拨弦动作实际上是沿着弧线或半圆而不是直线，即使我们并不总是这样认为它们。

For example, alternate picking from the elbow joint generates a semicircular motion:
例如，从肘关节交替拾取会生成半圆运动：

The actual orientation of this semicircle can vary based on a number of factors. In this illustration, the forearm approaches the strings at approximately a 45-degree angle, which is a general but more or less accurate approximation of elbow technique. This allows the joint to trace a correspodingly diagonal path with respect to the strings, such that the bottom of the downstroke approaches the electronics, while the top of the upstroke approaches the upper bout of the guitar’s body.
此半圆的实际方向可能因多种因素而异。在这个插图中，前臂以大约 45 度的角度接近琴弦，这是肘部技术的一般但或多或少准确的近似值。这允许关节相对于琴弦追踪相应的对角线路径，这样下冲程的底部接近电子设备，而上冲的顶部接近吉他琴身的上部。

By comparison, alternate picking from the wrist joint generates a curved motion in a similar plane, just with a smaller radius because the pick and the wrist aren’t as far apart:
相比之下，从腕关节交替拾取会在相似的平面上产生弯曲的运动，只是半径较小，因为拾取器和手腕之间的距离不远：

But the wrist is a multi-axis joint. If we keep the arm in the same position and simply change the direction the wrist is moving, we can actually generate a curved motion in a plane perpendicular to the guitar’s body:
但手腕是一个多轴关节。如果我们将手臂保持在相同的位置并简单地改变手腕的移动方向，我们实际上可以在垂直于吉他琴身的平面上产生弯曲的运动：

When we use this motion, wrist flexion and extension, the pick actually moves toward and away from the body along a semicircular path. Not only that, but the wrist can actually combine these two axes of motion, creating all kinds of diagonal and semicircular motions which don’t move strictly parallel or perpendicular to the guitar. We’ll learn more about why you’d want to do something like that when we get to escape motion.
当我们使用这个动作时，手腕屈曲和伸展，拨片实际上会沿着半圆形路径向身体移动和远离身体。不仅如此，手腕实际上还可以结合这两个运动轴，产生各种对角线和半圆运动，这些运动并不严格平行或垂直于吉他移动。当我们开始转义运动时，我们将详细了解您为什么想要做这样的事情。

Efficient Muscle Usage 高效肌肉使用

It may seem obvious why we would describe a back-and-forth motion as “alternating”, but there’s a deeper reason. In a true alternate picking technique, it’s not just the pick’s direction that alternates, but also the muscle usage. During each direction of the alternate picking motion, only one group of muscles is active while the other group rests. So each group in the pair only works half the time — one during the downstroke, and the other during the upstroke.
我们将来回运动描述为 “交替” 的原因似乎很明显，但有一个更深层次的原因。在真正的交替拨弦技术中，交替的不仅仅是拨片的方向，还有肌肉的使用。在交替采摘动作的每个方向上，只有一组肌肉处于活动状态，而另一组肌肉则处于休息状态。因此，对中的每个组都只工作一半的时间——一个在下冲程期间，另一个在上冲程期间。

This built-in rest period dramatically improves recovery, allowing trained alternate pickers to play prolonged sequences without fatigue. For example, metal master Brendon Small uses his awesome elbow-driven alternate picking technique to play long tremolo melodies while remaining relaxed:
这种内置的休息时间极大地改善了恢复，使训练有素的替代拾取者能够长时间播放序列而不会感到疲劳。例如，金属大师 Brendon Small 使用他出色的肘部驱动交替拨弦技术，在保持放松的同时演奏长长的颤音旋律：