For example, your ability to touch your thumb to your fingertips or give a thumbs up is thanks to opposition movement, facilitated by your saddle joint, which makes your thumbs opposable.

例如，你的拇指接触指尖或竖起大拇指的能力要归功于你的马鞍关节促进的对向运动，这使得你的拇指可以对向。