File a Secondary claim or normal?

Within a year of getting out I filed a set of claims for some things, one of them being lower back pain. This was eventually deferred and later denied.

I ask the questions because I want to file another claim to get it service connected. In that initial claim I had filed for broken foot / pain residuals which is SC, which had eventually given me lower back pain due to lifting very heavy things incorrectly with bad form for years following that.

Since I filed the original claim by itself, should I do that again or just file it as a secondary to my foot and include more evidence?