I walk slowly, but I never walk backward.
I am a slow walker, but I never walk backwards.
I walk slowly, but never backwards.
It doesn't mater if you're a slow walker, so long as you don't walk backwards.
I am a moderate walker, however I never stroll back.
I always [or "often"] walk slowly, but I never walk backwards.
I was born and have ever remained in the most humble walks of life.