For a little while, running barefoot was a popular trend—until the uninitiated started stepping on rocks and splitting their toes open on curbs. Then the industry lashed back, unloading super-soft marshmallow sneakers that felt like you were running inside a bouncy house. Now we’re at a good equilibrium, with shoe companies offering all ranges of shoes—it’s a buyer’s market no matter your preference.

And yet, while shoe companies may have figured out the market of ground-pounders, scientists are still puzzled by it. Prevailing wisdom in running circles had long held that forefoot strikers—that is, people who landed on the balls of their feet—caused less impact on their bodies than people who landed on their heels. But a new study out of Harvard shows that how runner's foot hits the ground might not actually make a difference.

Researchers looked at 110 middle-aged barefoot runners, 69 who were injured (shocking) and 41 who were healthy, according to new research presented at the annual Association of Academic Physiatrists Annual Meeting. The researchers then threw them all on a treadmill, aimed a high-speed camera aimed at their legs, and let ’em rip.

“We hypothesized that those rearfoot strike runners that had higher foot and tibial angles would have higher impact loading rates, and therefore would have a higher risk of a running injury,” said Robert Diaz, M.D., resident physician at Spaulding Rehabilitation Hospital/Harvard Medical School and lead author.

But that’s not what they found. In fact, there was no correlation between rearfoot strikers and impact rates, Diaz said.

While the study is obviously limited—it's hard to draw too many hard conclusions from a look at 110 people—it seems that many factors contribute to how hard your body absorbs running impact, and not just how you land. The main takeaway: You'll need to find your own "correct" way to run—be it barefoot or in moon boots.

“For those runners who are interested in lowering their impact loading and injury risk, we recommend evaluation in a running lab,” Diaz said.

And in the meantime, if shin splints are bothering you, here's a look at nine ways to heal up.