Is it true that if you tickle a babys feet it can cause speech problems?

Not true: I do not believe that there is any evidence that this is true.

ThisLittlePiggy,etc: If you tickle your little one's feet and he starts laughing, that's good and just do it sparingly or as a short game but not to the point of annoyance. If he draws away, irritated, then don't do it. Other than that, there is nothing I could find to support the idea that tickling feet will "cause" or predispose to any kind of speech problem.