I'm old, fat, and gimpy. I found the best way for me is to sit on my but and use a hula hoe, a tool I used to think was worthless. I reach out near horizontal with the handle, and with one hand pressing hard in the middle of the handle pull with the other. The blade works down about and inch whacking the roots. The weeds sit there like nothing happened, but the next stroke is rake like and the weeds come out near effortlessly. I can work the tool around the bacca like a doc with a scalpel.
Is this what you are talking about?
I looked at the one they have here: http://www.johnnyseeds.com/p-5496-5-stirrup-hoe.aspx I may buy one over the winter.