How to Beat Stress Fractures

http://well.blogs.nytimes.com/2009/12/01/phys-ed-how-to-prevent-stress-fractures/

Phys Ed: How to Prevent Stress Fractures


By GRETCHEN REYNOLDS

MIXA/Getty Images



Stress fractures are one of the more pernicious injuries in sports, afflicting the experienced and the aspiring, with no regard for competitive timing. Last year, Tiger Woods managed to win the U.S. Open despite suffering from stress fractures in his left leg (as well as other leg and knee injuries), while the great British marathoner Paula Radcliffe struggled through the Beijing Olympics Marathon on a leg barely recovered from a stress fracture, one of several she’s suffered. The International Association of Athletics Federations, the world governing body for track and field, recently described stress fractures, with a kind of grim resignation, as “the curse of athletes.”

But studies published in this month’s issue of the journal Medicine & Science in Sports & Exercise offer hope that, at least for runners, simple alterations in their stride or in the strength of their legs might reduce their risk for the most common type of stress fracture.

In one of the studies, undertaken at the University of Minnesota, researchers recruited 39 competitive women runners, ages 18 to 35, and started measuring them. In particular, the scientists wanted to examine the size and shape of their shinbones, or tibias. About half of all stress fractures occur in the tibia, studies show. When you run or jump, that bone is pulled and bent. Sometimes, microscopic fissures form. In most cases, these tiny cracks heal quickly. But, sometimes, continued activity overwhelms the bone’s capacity to recover. The cracks grow and combine into a fracture.

The Minnesota researchers wanted to see whether the shinbones of the runners with a history of stress fractures were weaker than those without. Earlier studies suggested that this would be the case. But few studies have examined the size of the runners’ calf muscles. Bones tend to adapt to the muscles around them; puny muscles can mean puny bones. The Minnesota scientists, using a new machine that examines bone in three dimensions and measuring the runners’ leg muscles, found that, surprisingly, the injured runners’ bones were as strong, in relation to their muscle size as the bones in the uninjured runners. But the injured runners had significantly smaller calf muscles and therefore also slighter bones. The primary difference, the researchers concluded, between the women who suffered stress fractures and those who hadn’t was the size (and presumably strength) of their calf muscles.

This finding should be encouraging to anyone who has had a tibial stress fracture or would prefer not to. “It does seem as if strengthening the calf muscles may be a very easy way” to reduce fracture risk, says Moira Petit, an associate professor of kinesiology at the University of Minnesota and an author of the study. In addition, she said, “our data suggest that you don’t have to strengthen the muscle by much.” A small increase of bulk, achievable by, for instance, rising up on to your toes and sinking back to the floor 10 or 12 times every day, might be enough. Adding even a small amount of calf muscle “serves two purposes,” Ms. Petit says. First, “the strength of the bone will usually increase” in response to the added muscle. And, as a bonus, the new muscle “can absorb more” of the forces generated when you run. So even as the tibia strengthens in response to the new muscle, it also is subjected to less shock. “Really, there’s no downside to this,” Ms. Petit says.

Her results, though, may apply primarily to women; she’s studying male runners, but so far, she says, isn’t seeing the same relationship between their calf-muscle size and bone strength. The other study in the current Medicine & Science in Sports & Exercise, however, did focus on men and their stress fractures, although, in this case, the lead researcher suggests that the findings would be true in women as well. In the work, from Iowa State University in Ames, computer modeling was used to predict what would happen to stress fracture risk if runners changed their strides. The researchers attached reflective markers to the bodies of 10 former or current collegiate-level cross-country runners and had them run repeatedly down a runway nearly 30 meters long, making sure to step onto a force plate that measured how hard they were striking the ground. During successive runs, the men were asked to shorten their natural strides, while maintaining their pace. The scientists entered the data into computer programs that calculated just how much force was being applied to the shinbone under different striding conditions. The researchers determined that reducing stride length by about 10 percent seemed to reduce the stress on the tibia enough to lower the risk of a stress fracture.

Why, though, should shortening your stride affect your tibia at all? “Think of it this way,” says Brent Edwards, lead author of the study and now a post-doctoral research fellow in the Department of Kinesiology and Nutrition at the University of Illinois, in Chicago. “If you spend less time in the flight phase of running” — meaning in the air — “you’ll hit the ground with less force.” On the other hand, you’ll hit the ground more often. But in Mr. Edwards’s models, the reduction in pounding from an abbreviated stride outweighed the shock from a few additional strides per mile.

Even for those of us without a biomechanical expert in the house, gauging a 10 percent reduction in stride is not difficult, Mr. Edwards says. “Ten percent is about as much as you can shorten your stride without it beginning to feel quite uncomfortable,” he says. And absolute precision isn’t necessary. “Seven or eight or nine percent is fine,” he says.

Neither Ms. Petit nor Mr. Edwards suggests, of course, that any, single prevention approach will end all tibial stress fractures. “There are so many elements involved,” Ms. Petit says. Training, hormones, genetics, diet and shoe choice probably all play a role. “But if there’s something easy and benign that you can do to lessen the risk,” she asks, “why not?”

Easy Run - Thursday 3rd December 2009

Did an easy run of 75.51 minutes, easy pace, rhythm running, coming in after a short layoff, this was a good effort.

Easy Run - Tuesday 1st December 2009

Did an easy run of 31.02 minutes today, coming into running after a layoff of exactly one week due to severe cold and cough, did not want to exert too much.

Katha Prize Short Stories

Just finished this book series Volume I. Katha series is basically the translated versions of short stories originally written in various Indian languages. There are some lovely stories here such as "Crows, Crows and Crows" by Bhupendranarayan Bhattacharyya, "Kashi" by Ashok Srinivasan, "Hands" by Rekha and "Reflowering" by Sundara Ramaswamy. A delightful collection.

--
Ram
Bombay
http://www.goodreads.com/review/list/1125607
http://ram-books.blogspot.com/
http://ram-running.blogspot.com/

Dr. Ashis Roy attempts his 100th marathon at Mumbai 2010

Enclosed interview with Dr. Ashis Roy, who will be running his 100th marathon in Mumbai 2010. A few gems from him:

"Running is for us what flying is for birds. It builds fundamental strength. It involves every part of your body, your heart, your brain, your blood circulation."

"Running is never a problem if you take care of yourself and if you are properly hydrated."

Dr. Roy started running marathons only at the age of 52. 

I could not get the URL therefore pdf file  is uploaded.

--
Ram
http://ram-books.blogspot.com/
http://ram-running.blogspot.com/

The Brainfever Bird

Just finished reading "The Brainfever Bird" by Irwin Allan Sealy. While his first book viz. "Trotternama" was a magnum opus, this was definitely yawn inducing, a big letdown from his expections from his first book. To be commended though, is Sealy's narrative style which is very powerful and imaginative and a lot of attention to details. He is definitely one to watch out for.

How Necessary is Stretching

http://well.blogs.nytimes.com/2009/11/25/phys-ed-how-necessary-is-stretching/

Phys Ed: How Necessary Is Stretching?


By GRETCHEN REYNOLDS




For research published earlier this year, physiologists at Nebraska Wesleyan University had distance-running members of the school’s track and field team sit on the ground, legs stretched before them, feet pressed firmly up against a box; then the runners, both men and women, bent forward, reaching as far as they could past their toes. This is the classic sit-and-reach test, a well-established measurement of hamstring flexibility. The runners, as a group, didn’t have exceptional elasticity, although this varied from person to person.



Overall, the women were more supple, as might have been expected. Far more telling was the correlation between the various runners’ tight or loose hamstring muscles and their running economy, a measure of how much oxygen they used while striding. Economy is often cited as one of the factors that divide great runners from merely fast ones. Kenyan distance runners, for instance, have been found to be significantly more economical in their running than comparable Western elites.



When the Nebraska Wesleyan researchers compared the runners’ sit-and-reach scores to the measurements of their economy, which had been garnered from a treadmill test, they found that, across the board, the tightest runners were the most economical. This was true throughout the groups and within the genders. The inflexible men were more economical than the women, and for both men and women, those with the tightest hamstrings had the best running economy. They also typically had the fastest 10-kilometer race times. Probably, the researchers concluded, tighter muscles allow “for greater elastic energy storage and use” during each stride. Inflexibility, in other words, seems to make running easier.



For years, flexibility has been widely considered a cornerstone of health and fitness. Many of us stretch before or after every workout and fret if we can’t lean over and touch our toes. We gape enviously at yogis wrapping their legs around their ears. “It’s been drummed into people that they should stretch, stretch, stretch — that they have to be flexible,” says Dr. Duane Knudson, professor of biomechanics at Texas State University in San Marcos, who has extensively studied flexibility and muscle response. “But there’s not much scientific support for that.”



In fact, the latest science suggests that extremely loose muscles and tendons are generally unnecessary (unless you aspire to join a gymnastics squad), may be undesirable and are, for the most part, unachievable, anyway. “To a large degree, flexibility is genetic,” says Dr. Malachy McHugh, the director of research for the Nicholas Institute of Sports Medicine and Athletic Trauma at Lenox Hill Hospital in New York and an expert on flexibility. You’re born stretchy or not. “Some small portion” of each person’s flexibility “is adaptable,” McHugh adds, “but it takes a long time and a lot of work to get even that small adaptation. It’s a bit depressing, really.”



What happens to our muscles and tendons, then, when we dutifully stretch before a run or other workout? Doesn’t this lengthen our muscles, increasing our flexibility and range of motion?




According to the science, the answer appears to be no. “There are two elements” involved in stretching a muscle, Dr. McHugh says. One is the muscle itself. The other is the mind, which sends various messages to the muscles and tendons telling them how to respond to your stretching when the discomfort of the stretching becomes too much. What changes as you stretch a muscle is primarily the message, not the physical structure of the muscle. “You’ll start to develop a tolerance” for the discomfort of the stretch, Dr. McHugh says. Your brain will allow you to hold the stretch longer. But the muscles and tendons themselves will not have changed much. You will feel less tight. But even this sensation of elasticity is short-lived, Dr. McHugh says. In a new review article of the effects of stretching that he co-wrote and that will be published soon in The Scandinavian Journal of Medicine and Science in Sports, he looked at the measurable impacts of a number of different stretching regimens. What he found was that when people performed four 90-second stretches of their hamstrings, their “passive resistance” to the stretching decreased by about 18 percent — they felt much looser — but the effect had passed in less than an hour. To achieve a longer-lasting impact, and to stretch all of the muscles involved in running or other sports, he says, would probably require as much as an hour of concerted stretching. “And the effects still wouldn’t be permanent,” he says. “You only see changes” in the actual, physical structure of the muscles “after months of stretching, for hours at a time. Most people aren’t going to do that.”



And most of us don’t need to. “Flexibility is a functional thing,” Dr. Knudson says. “You only need enough range of motion in your joints to avoid injury. More is not necessarily better.” For runners, extremely tight hamstrings and joints have been found in some studies (but not all studies) to contribute to overuse injuries. But somewhat tight hamstrings, as the Nebraska Wesleyan study showed, can make you more economical. Some degree of inflexibility may make you a better runner.



How then to judge your own flexibility? “The sit-and-reach test is pretty good” for at-home evaluations, Dr. Knudson says, at least of your back and hamstring muscles. Using a staircase, sit and straighten your legs so that your feet push against the bottom step, toes upright. Stretch forward. “Try to lay your chest onto your thighs,” he says. If you can reach past your toes, you’re more than flexible enough. (No one yet has devised a way to reduce flexibility, by the way, although some Olympic-level coaches in other countries are rumored to be trying.)



If, on the other hand, “you can’t get anywhere near your toes, and the lower part of your back is practically pointing backward” as you reach, then you might need to try to increase your hamstring flexibility, Dr. Knudson says, to avoid injuring yourself while running, cycling or otherwise exercising. You can find multiple hamstring stretches on YouTube, although you should consult with a physical therapist before replicating them at home; proper technique is important to avoid injury. “You won’t get a lot of change,” Dr. Knudson says, ” but a little may be all you need.”