A group of researchers at Harvard Medical School are trying to get under the subject of super-runners. No, we don’t mean artificially created runners, but those runners who run so naturally that they are never in the danger of getting injured.
The Harvard Gazette reports about the study out of Harvard Medical School and the National Running Center in Spaulding Rehabilitation Hospital. Here, led by Irene Davis, Professor of Physical Medicine and Rehabilitation, the group found that runners who had never been injured “landed each footfall more softly than a group who had been injured badly enough to seek medical attention.”
The study gathered 249 active female runners who have a weekly mileage of almost 20 miles a week and are heel strikers. The test subjects responded to a monthly online questionnaire that explored their injury history. Researchers then examined reports from the 144 who experienced a mild injury during this two-year period, and the 105 who didn’t, but did not find any great startling facts.
So they looked at the subset data i.e those who had sought medical attention for their injuries, and those who not only went uninjured but who have never seemingly been injured. Now, they started to see a pattern in a variable called “vertical average loading rate,” – highest in the seriously injured runners in the study and lowest in the uninjured group.
Vertical average loading rate measured the suddenness of impact among the runners, and here the softer landers were better off. Loading rate is the speed at which you apply forces to the body so a lower rate will minimize tissue stress to the runner.
During a typical running stride, the foot is in contact with the ground for just about a quarter of a second; the fraction that made the difference between the two groups was only 50 milliseconds. Even so, when repeated thousands of times, that small difference can take a toll, Davis said.
The key takeaway from the study is that a softer footfall may be less assertive but is definitely the key to reducing the likelihood of injury, especially among heel runners.
Soft-landing steps tend to be very quiet. Runners should take out the earbuds and pay attention to the sound of their footsteps.“If you land louder, it’s harder,” Davis said. “It’s work, but you can make your foot-strikes softer.”
Davis’ research focused on heel-strikers exclusively, since the group determined that’s what a majority of runners these days are. The added shock, multiplied over thousands of footsteps, could explain high injury rates. For these heel runners, practicing a softer landing could be the key to staying injury-free.