It is possible to go back to a thread after a post has been made. There are 2 ways to do so.

First is per user, so each member must do the change for themselves.

In the users profile go to look and layout from there check Return to topics after posting by default. and save the page

Second is for all users, so all members old and new will have the change applied automatically to their account.

In the admin panel go to current theme or themes and layout then click on Member Options. From here you can modify the setting for all new members or all existing members by clicking the appropriate link, Configure guest and new user options for this theme or Change current options for all members using this theme, this must be done for each and every theme. On the next page you can select the Return to topics after posting by default. option and save the page.