4-4 point 5-5 shoulder hit
A shoulder hit against the 4-4 point on the 5-5 point like does here against White's corner, is an unusual play. In isolation, it will strengthen White's corner, while the influence obtained won't compensate. Therefore it's probably to be expected only in specific whole board situations, when such influence helps a global fight.
This is the type of situation where one might see a professional play the 5-5 point shoulder hit. White is using the influence to attack the black group below on a large scale.
Fujisawa Hosai (White) vs Takemiya Masaki (Black), 1978
In this game, Takemiya chose to play the 5-5 shoulder hit.
Play continues: with 1-9 Black improves his moyo. White chooses to enter at 10. 11 is a key move. White’s gain in the bottom left corner isn’t too big; Black gets to reduce it with the moves 17 and 19. After that the focus switches to the fight at the top.
See also /Discussion