SAN FRANCISCO (CBS 5) - One of the most popular activities in the Bay Area is running. But are we running wrong? In other words, are we running in such a way that our technique puts our bodies at higher risk for injury?
The statistics are suggestive: a very large percentage of runners get injured every year.
Experts note how 56% of recreational runners and as many as 90% of runners training for a marathon are injured each year. And half those injuries involve the knee.
Researchers have come up with a strategy to cut the risk. The idea: run like you're running on eggshells and take lighter, quicker steps.
In other words, your right foot should hit the ground 80 to 90 times a minute, shortening your stride.
"By increasing the number of steps you take during running, that intuitively decreases the stride length and then it greatly reduces the impact forces that are generated," said Dr. Richard Souza.
Dr. Souza is research director at UCSF's Human Performance Center as well as a physical therapist affiliated with the Department of Physical Therapy and Rehabilitation Science. At the lab, scientists quantify in 3-D how a runner moves by affixing tiny retro-reflective markers to specific parts of his or her body. Specialized cameras then capture the markers as they move in space, allowing the team to reconstruct the runner's skeleton for analysis.
"If we can determine that a certain injury is associated with a certain pattern, we can then develop interventions targeted to counteract that faulty movement pattern," noted Dr. Souza.
He showed us the tale of two skeletons, reconstructed from two runners.
On the lab's computer monitor, a clip played out showing how one runner's skeleton was captured taking long strides and fewer steps.
"You can see the foot is far extended in front of the pelvis," explained Dr. Souza. "What that creates is this very large breaking force and this very large impact which is propagated up the lower extremity."
On the bottom of the computer screen, a second clip: a runner's skeleton that was captured taking more steps, but with each step beginning directly under the body.
"There's a much shorter stride rate, they're not reaching nearly as much," said Dr. Souza, adding how "you can see the person was loading much more underneath themselves and they didn't have that much breaking force with each step."
The difference in force is captured on a graph that looks like a bell curve: the runner with the long stride creates what's called an impact peak which looks like a big dent into the curve - and that's linked to injury.
The runner who takes more steps does not create a visible impact peak.
"That impact peak is completely obliterated," said Dr. Souza.
And by eliminating the impact peak, by increasing one's step rate and decreasing the stride, runners may be protected from injuries.
Not everybody needs to boost the number of steps they take. At this point, the science shows that those who may benefit the most are runners who have sustained previous injuries such as stress fractures.
Studies are currently underway to determine whether increasing your step rate or cadence will prevent all runners from getting injuries in the future.
"Running with better technique is going to be much safer with people and give them better longevity to do the things they want to do," said Dr. Anthony Luke, a sports medicine specialist at UCSF.
At the UCSF Center, Dr. Luke and his team has developed a Run Safe program where scientists will look at a runner's biomechanics, strength, flexibility, diet, as well as footwear.
"We want to make sure they are running the best way and that's a lot of information and awareness and educations, and all of those play a big role in getting to run safely," explained Dr. Luke.
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