Hummingbirds however, turn their wrists during the upstroke, changing their wing's angle to flap in a figure 8 pattern that continually generates lift throughout their wingbeats.

然而，蜂鸟在上击时转动手腕，改变膀的角度，以 8 字形模式打，在整个不断产生升力。

Their wing joints are also stiffer than those of flying birds, which helps them produce thrust on both the downstroke - like most birds do - and on the upstroke of the wing.

它们的膀关节也比飞鸟的关节更硬，这有助于它们像大多数鸟类一样在下击和上击时产生推力。