I noticed why watching a lot of Edberg videos that his forehand movement was changing during his career, sometimes quite drastically. This was already showed by somebody about the Edberg serve. While Edberg's coach once said that he would not change Edberg's forehand, obviously there were some tinkering with it during the years. In 1984-1986 his arm is perceptively very straight when he takes back the recket, indeed it looks like a bit of Gustafsson, another Swede. In 1987 there is a slight change as the arm is a bit more bend in the take back. This remains so until 1989. Then in 1990 and 1991 he had again a slight change. He holds his racket face down and it gives the effect that in a way it looks like he is "pushing" the ball. The racket always remains low in the take back, not as high as before and there is more bend in the arm, especially at the elbow. Then in 1993 he had again a very high take back. All in all as I perceive it he was making these changes, but he never changed his grip which was basically some mix of continental and eastern, and his finish remained the same for more flat shots (above the shoulder finish) and sometimes an almost strangely "hooking" finish (in 1990 semi in Wimbledon against Lendl in youtube video you can see that 4:13 plus the replay) and called wiped forehand by the speaker. Actually he could hit some quite wild topspin, especially cross court. Yes it was a liability, but when this forehand was on it was great to see it.