By Stephen Beech

Runners who wear thick-heeled trainers are more likely to get injured than those who wear flatter running shoes, new research warns.

The study also found that runners with thicker heels could not accurately identify how their foot landed with each step, a likely factor in the high injury rates.

Because flatter shoes are associated with less injury, the American research team says they are likely the best option for most runners to help improve sensation with the ground and learn to land in a controlled manner.

But transitioning to a different shoe type or foot strike pattern can also risk injury and must be done gradually, something that study lead author Dr. Heather Vincent knows from personal experience.

Dr. Vincent, director of the University of Florida's Health Sports Performance Center, said: "I had to teach myself to get out of the big, high-heeled shoes down to something with more moderate cushioning and to work on foot strengthening.

"It may take up to six months for it to feel natural. It's a process."

Both foot strike patterns and shoe type have been linked to running injuries in previous studies, but the interaction between the two has been difficult to identify from small groups of runners.

Hundreds of athletes visit the University of Florida's Sports Performance Center and Running Medicine Clinic each year, allowing the research team to pull data from more than 700 runners and six years of information on runners' shoe type and injury history, making it one of the largest and most comprehensive studies of its kind.

Data about running gait was also acquired using specialized treadmills and motion capture videos for the study published in the journal Frontiers in Sports and Active Living.

Dr. Vincent says that what became clear - after controlling for factors like age, weight, running volume and competitiveness - was that shoes with thicker heels confused runners about their gait - confusion that was strongly linked to injury.

She said: "The shoe lies between the foot and the ground, and features like a large heel-to-toe drop make it more challenging for runners to identify how they're striking the ground.

"That clouds how we retrain people or determine if someone is at risk for future injury.

"The runners who correctly detected mid- or fore-foot striking had very different shoes: lower heel-to-toe drop; lighter; wider toe box."

Although the associations between high-heeled shoes and injury were clear, the research team says it's difficult to prove that heel-to-toe drop directly causes the injuries.

The team plans to run controlled studies to see if changing shoe type affects runners' accuracy of foot strike detection and injury rates.

They say that would help identify the true cause of common injuries and suggest the best fixes.

Dr. Vincent added: "We want to translate what we find to meaningful ways to help runners modify their form to reduce injury risk and keep them healthy for the long term."

FOX28 Spokane©