If you look at current running shoe offerings, you won’t see much evidence that minimalism and barefoot running were white-hot five years ago. Most midsoles are high and plush, and even many racing shoes have stability features. One tenet of minimalist shoe design, however, has become widespread—a relatively low heel-to-toe drop. That’s the difference in the combined height of the midsole and outsole where the back and front of your feet sit in a shoe. Maximalist shoes, such as nearly all Hoka One Ones and most Altras, offer plenty of cushioning, but do so on a flat platform. Many other manufacturers have also retained minimalism’s emphasis on little to no difference between heel and forefoot height (while still offering other models with a conventional heel-to-toe drop of 10-12 millimeters). According to minimalists, one benefit of a low or nonexistent heel-to-toe drop is reduced risk of injury. Shoes with a large drop encourage severe heel striking, it’s said, which might contribute to knee injuries.

Advocates of a small heel-to-top drop also say that allowing feet to run more as they would when unshod more evenly distributes impact forces. In addition, minimalists say, being tilted forward by a high heel can throw your body out of alignment and set you up for compensatory injuries.nike shoes with pocket But a shoe’s drop might not have anything to do with whether you get injured wearing it, suggests a new study published in The American Journal of Sports Medicine.good walking shoes for hot weather Researchers at the Luxembourg Institute of Health followed 533 recreational runners for six months while the subjects did all of their running in models with a 0-, 6-, or 10-millimeter drop. nike trainer shoes 2014

The shoes’ respective stack heights were 21 millimeters in the heel and forefoot; 21 millimeters in the heel and 15 millimeters in the forefoot; and 24 millimeters in the heel and 14 millimeters in the forefoot. best walking shoes to keep feet coolThe shoes were otherwise identical.puma sports shoes sale online With injury defined as a leg or lower-back pain that resulted from running and cut into planned training for at least one day, 25 percent of the runners reported being injured during the six-month study period. running shoes heavy weightThe study’s main finding was that injury rates among the three groups were similar—runners got injured at roughly the same rate whether their shoes had a heel-to-toe drop of 0, 6, or 10 millimeters.

This result doesn’t mean that a shoe’s drop is irrelevant. In 2015, in a review of research on running shoe construction and injury rate, famed biomechanist Benno Nigg found no evidence that shoes change injury patterns. Nigg has long recommended that runners let what he calls “the preferred movement path” and “the comfort filter” guide shoe choice—roughly stated, how much a shoe feels like an extension of your feet when you run in it. By that standard, some runners will prefer shoes with a high heel-to-toe drop, while others will gravitate toward flatter models. In addition, focusing on shoe drop might help runners with specific injury histories, says sport podiatrist Brian Fullem, author of The Runner’s Guide to Healthy Feet and Ankles. “As a general rule, if someone has forefoot pain such as a neuroma, or arthritic changes in the big toe joint, then I recommend trying a lower-drop shoe. If someone has heel pain from plantar fasciitis or Achilles or posterior tibial tendonitis, then I recommend a more traditional heel drop of 12 millimeters,” Fullem says.

Although the study found no overall difference in injury rate by shoe drop, there’s an important caveat from the results: Among more frequent runners in the study, those in the low-drop shoes (either 0 or 6 millimeters) had a higher injury rate than the frequent runners in the shoes with a 10-millimeter drop. “One possible explanation may be that, in regular runners, the transition from their usual running shoes to the low-drop versions was not progressive enough and increased injury risk,” lead researcher Laurent Malisoux told Runner’s World by email. As Malisoux points out, 78 percent of the subjects hadn’t run in a low-drop shoe before the study, which had some of them suddenly switching to doing all of their running in a low-drop shoe. “One might expect that runners with a certain amount of running experience yet well-adapted musculoskeletal system are suitable candidates for low-drop shoes, but safe transition could actually require a longer period [than for beginning runners],” Malisoux says.

Fullem agrees that runners should gradually transition to shoes with a lower drop, including racing flats. “In the beginning of a competitive season, start doing striders in your racing flats after a run,” he says. “I also recommend transitioning to doing speed sessions in the racing flats. It is very common after the first track, cross-country or road race of the year to have sore calves if  you have not done enough running in the lower-drop shoes.” Fullem and Malisoux agree that rotating among shoes, including ones with different heel-to-toe drops, is a good strategy for most runners. In 2015, Malisoux published a study that found a lower injury rate over a 22-week period in runners who alternated shoes compared to those who always ran in the same model. “Shoes with different features may lead to a variation of the load applied to the musculoskeletal system,” Malisoux says.(Editor's Note: This story was updated on April 1 to clarify a comment from Jay Dicharry about the impact of running in minimal-drop shoes.)

By name, you'd think zero-drop shoes are generally the most minimalist of all running shoes. Some of these shoes are quite minimal, but it's more that those shoes have a level profile and have little or no "drop" from where the heel sits in a shoe and where the forefoot sits in a shoe. In other words, the shoes are designed without a built-up heel or a steep slope from the heel to the forefoot and instead allows a runner’s foot to sit relatively parallel to the ground. For years, traditional training shoes have been built with a 12-15mm heel-toe differential. But in the shoe revolution we're in now, moderate minimalist shoes typically have a 4-10mm heel-toe drop and zero-drop shoes are generally those that fall in the 0-4mm range. Many studies in recent years have suggested that a significantly raised heel is one of the culprits to many common running injuries, partially because they tend to encourage heavier heel striking, higher impact forces and greater rotational forces (overpronation).

Running gait and running injury expert Jay Dicharry, MPT, says running in shoes with a near-level profile is an ideal situation because it allows the body to run in the most natural position possible without having to compensate too much for how the shoe is trying to dictate the movement of the foot. “I think very, very close to zero is where things should be, but it will take some time and effort for most runners to get there,” says Dicharry, the director of the SPEED Clinic at the University of Virginia’s Center for Endurance Sport. “But not every single person who runs in a zero-drop shoe is going to choose that for a shoe for running fast and hard in. Maybe it’s a learned effectiveness; Zero-drop shoes haven’t been around long enough for people to get fast performance times in at the elite level.” Portland, Oregon-based podiatrist and a competitive masters runner Ray McClanahan has also embraced the concept of zero-drop and minimally sloped shoes. “I’m so pleased to see the industry changing and seeing what our feet can do,” McClanahan says.

“I’m all for it. In 17 years of reading all of the medical literature, I can’t come up with a reason our heel should ever be elevated above our forefoot.” Still, medical experts and running form gurus alike recommend that runners take time to transition to shoes with lower ramp angles that what they’ve been running in, and Dicharry and McClanahan agree. Even if you’ve been running and racing for years, if you don’t conscientiously work on form and strength with minimal running, you could wind up with sore calf muscles, strained Achilles tendons, aching feet or more serious injuries. While Dicharry recommends that runners transition toward wearing more minimal shoes while also improving strength and flexibility, he admits there is probably a tradeoff between joint health and performance. "In general, with minimal shoes, most runners typically adopt a gait pattern that decreases the loading rate (impact forces) on the feet, knees, ankles, hips, and lower back on every step," Dicharry says.

"However, the physics of running with this form are very different that a typical heel-toe pattern. Thus, we suggest that runners take time to transition into the style of running appropriately. Caveat: If someone is in fact going to continue to run with a very prominent heel-strike pattern, we have seen evidence that a number of traditional high-heeled trainers do in fact result in lower loading rates than more minimal designs — again, only if they are running with a prominent heel-strike pattern." If you’ve been running in traditionally built trainers, changing first to a moderate minimalist shoe that has a 4-8mm heel-toe drop is a good way to start, Dicharry says. (See Dicharry’s tips for transitioning to minimal shoes.) Here are six shoes in the zero-drop category with -1mm to 4mm of differentiation between the heel and forefoot. Altra The Instinct/The Intuition (available after 4/1/2011) From an upstart company that debuted this year, the Instinct and Intuition are flat shoes with 10mm of material under foot from heel to toe.