WASHINGTON (June 8, 2010)—According to one recent estimate, Americans are spending a staggering $86 billion a year to care for aching backs with MRIs, pain pills, nerve blocks, even acupuncture.

But research finds little evidence that the population got better as the medical bills soared over the past decade.

The reality is that time often is the best antidote.

Most people experience back pain at some point, but up to 90 percent will heal on their own within weeks.

In fact, in run-of-the-mill cases, doctors aren't even supposed to order an X-ray or MRI unless the pain lingers for a month to six weeks.

Yet a study last year found nearly 1 in 3 aching Medicare patients get some kind of back scan within that first month.

The bigger problem is that there's no one-size-fits-most treatment.