A new review of the evidence finds that only a handful of common remedies provide a modest benefit for acute or chronic back pain.

Low back pain affects an estimated one in four American adults and is the leading contributor to disability globally. In most diagnosed cases, the pain is considered “nonspecific,” meaning it doesn’t have a clear cause. That’s also partly what makes it so hard to treat.

Low back pain is one of the most common medical complaints in the world. Globally, over 600 million people suffer from it. That means at any given moment, millions of people are searching for relief—visiting doctors,