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.

Only around one in every 10 treatments were found to be effective in relieving lower back pain, according to a new study published in BMJ Evidence-Based Medicine.