repeat across the thumb

[Eway]

"Holding your thumb between thumb and index finger, exert pressure for several seconds. Repeat across the thumb, repositioning the working thumb and pressing the area below the nail."

What does "repeat across the thumb" mean? (I guess I'm confused by the word "across" here.)

[Anglika]

I suppose it means start at the bottom of the thumb and work towards the nail.

[queenbu]

Originally Posted by Eway

"Holding your thumb between thumb and index finger, exert pressure for several seconds. Repeat what you have just done but across the thumb, repositioning the working thumb and pressing the area below the nail."

What does "repeat across the thumb" mean? (I guess I'm confused by the word "across" here.)

The first time you put the thumb of the right hand, say, between the thumb and the index finger of the left hand and you exert pressure on the sides of the thumb (of the right hand). Then you change the position of the thumb and index finger of the left hand (works equally well if you change the posn of the thumb of the right hand) so that the pressure you now exert on it is across the thumb and not on its sides.You press the area below the nail not lower down.
That's how I see it. - q