That's true for both ands but specifically I was thinking about the left hand (for right handed golfer) as far as the pressure on the last three fingers.
A little drill to understand how finger pressure points of the left hand affect the release swivel, follow through and finish: make a swing but let the right hand come off the club before impact. Do it once with pressure only on the last three fingers and once with accure pressure on the forefinger and thumb and none on the last three fingers. Don't do that at home unless you have plenty of room under the ceiling !