Study: Want to Avoid Running Overuse Injuries? Don’t Lean Forward So Much

The ubiquitous overuse injuries that nag runners may stem from an unlikely culprit: how far you lean forward.

Trunk flexion, the angle at which a runner bends forward from the hip, can range wildly–runners have self-reported angles of approximately -2 degrees to upward of 25. A new study from the University of Colorado Denver (CU Denver) found that greater trunk flexion has significant impact on stride length, joint movements, and ground reaction forces. How you lean may be one of the contributors to your knee pain, medial tibial stress syndrome, or back pain.

“This was a pet peeve turned into a study,” said Anna Warrener, PhD, lead author and assistant professor of anthropology at CU Denver. Warrener worked on the initial research during her postdoc fellowship with Daniel Liberman, PhD, in the Department of Human Evolutionary Biology at Harvard University. “When [Lieberman] was out preparing for his marathons, he noticed other people leaning too far forward as they ran, which had so many implications for their lower limbs. Our study was built to find out what they were.”

The study was published in Human Movement Science.

A New Angle on Overuse Injuries

The head, arms and trunk constitute roughly 68% of total body mass. Small changes in trunk flexion have the potential to substantially alter lower-limb kinematics and ground reaction forces (GRF) during running.

To study the downstream effects, Warrener and her team recruited 23 injury-free, recreational runners between the ages of 18 and 23. They recorded each participant running 15-second trials at their self-selected trunk position and three others: a 10-, 20-, and a 30-degree angle of flexion. But to make the study work, they had to first figure out how to get each runner to bend at the right slant.

“We had to create a way in which we could reasonably force someone into a forward lean that didn’t make them so uncomfortable that they changed everything about their gait,” said Warrener. The team hung a lightweight, plastic dowel from the ceiling just above the runners’ heads, moving it up or down, depending on the angle needed.

Contrary to the team’s original hypothesis, the average stride length decreased 13 cm and stride frequency increased from 86.3 strides/min to 92.8 strides/min. Overstride relative to the hip increased 28%.

“The relationship between strike frequency and stride length surprised us,” said Warrener. “We thought that the more you lean forward, your leg would need to extend further to keep your body mass from falling outside the support aera. As a result, overstride and stride frequency would go up. The inverse was true. Stride length got shorter and stride rate increased.”

Warrener believes this may be due to a decrease in the aerial phase (if they’re not getting as much air time, runners will take shorter steps), which means leg swings quickened as a result of reduced forward movement.

“The act of swinging your leg is really expensive as you’re running,” said Warrener. “Swinging it faster as you lean forward may mean a higher locomotor cost.”

Compared to the participants’ natural trunk flexion, increased angles led to a more flexed hip and bent knee joint. A bigger lean also changed the runners’ foot and lower limb position, leading to an increased impact of GRF on the body (rate of loading by 29%; vertical ground reaction force impact transients by 20%).

The combination of trunk flexion angle, foot and leg placement, and GRF variables, shows that excessive trunk flexion could be one cause of injurious running form and, according to Warrener, is key for understanding how diverse running forms optimize economy and performance.

“The big picture takeaway is that running is not all about what is happening from the trunk down–it’s a whole-body experience,” said Warrener. “Researchers should think about the downstream effects of trunk flexion when studying running biomechanics.”

Source: EurekAlert!

New Sweets of Baumkuchen Specialty Store “Sennen no Ki” in Japan

Chocolate Mint Baumkuchen

The price for a box set of the three cakes is 475 yen (tax included).

5-Minute Daily Breathing Exercise May Equal Meds in Lowering Blood Pressure

Amy Norton wrote . . . . . . . . .

A quick daily “workout” for the breathing muscles may help people lower their blood pressure to a similar degree as exercise or even medication, a small study suggests.

The technique is called inspiratory muscle strength training (IMST), and it involves using a device that provides resistance as the user inhales — essentially working out the diaphragm and other breathing muscles.

Researchers found that over six weeks, the exercises lowered study participants’ blood pressure by nine points, on average.

And all it took was five minutes of training per day, said lead researcher Daniel Craighead, an assistant research professor at the University of Colorado, Boulder.

There are caveats, he said: Study participants had higher-than-normal blood pressure but were healthy. It’s unclear how well the technique would work for people in poorer health.

There’s also the question of how long the benefits last, Craighead said, though this study turned up some encouraging results. Even after the training ended, most of the blood pressure reductions were sustained for another six weeks.

That hints there is “something special” about the breathing exercises, according to Craighead. “We’re excited to study it further,” he added.

The findings were recently published online in the Journal of the American Heart Association.

Inspiratory muscle strength training has been studied for lung conditions like asthma and emphysema and for boosting athletic endurance, according to Craighead, who uses the technique in his own marathon training.

But a recent trial found that for people with sleep apnea — a nighttime breathing disorder — IMST also lowered blood pressure.

So Craighead’s team wanted to see whether the training could help people whose only health issue was elevated blood pressure.

The study — which was funded by the U.S. National Institutes of Health and the American Heart Association (AHA) — involved 36 adults aged 50 to 79. All had above-normal systolic blood pressure (higher than 120 mm Hg). Systolic pressure is the force your blood exerts against artery walls when your heart beats.

The researchers randomly assigned participants to one of two groups: In one, participants used a hand-held device that provides resistance during inhalation — similar to trying to suck through a tube that sucks back.

The other group performed a “sham” version of the exercise, using a device that provided little resistance.

“It’s not relaxing, like slow deep breathing,” Craighead said of the real training. “It’s more like exercise.”

Luckily, it’s a brief workout — 30 inhalations, or about 5 minutes, per day.

After six weeks, the study found, people in the IMST group saw their systolic blood pressure drop from an average of 135 mm Hg to 126 mm Hg.

The improvement is on par with medication, according to Craighead, and even better than what’s typical with exercise.

No one, however, is saying that people should dump their current prescriptions and buy an IMST device.

It “would not be wise” to simply stop taking blood pressure medications or exercising, said Dr. Karen Griffin, chairwoman of the AHA’s hypertension council.

She said the findings raise the possibility that IMST could bring added benefits, and even allow some people to take less medication. But Griffin agreed that further study is needed to see whether the exercises are as helpful for people with co-existing conditions like heart disease and diabetes.

As for why IMST helps lower blood pressure, it’s not yet clear, Craighead said.

But study participants in the IMST group showed certain measurable changes: an increase in nitric oxide, a chemical that helps dilate arteries, plus a decrease in C-reactive protein, a marker of inflammation in the blood vessels.

People interested in trying IMST for their high blood pressure should talk to their doctor first, according to Griffin.

“It’s always prudent to check with your physician,” she said, “although I suspect most healthy individuals would be able to add this to their daily routine without any significant health risk.”

Craighead said he does not necessarily see IMST as a replacement for whole-body exercise.

“If you can exercise, do it,” he said. “Exercise has many benefits other than blood pressure control.”

But, he added, IMST might be particularly helpful for people who can’t exercise because of health problems or injuries, or who lack safe places for exercise.

The devices do require a financial investment: The product used in this study, the POWERbreathe K3 trainer, costs about US$430, according to the manufacturer’s website.

Source: HealthDay

Caramelized Pears with Brandy

Ingredients

2 tablespoons lemon juice
6 under-ripe pears, peeled
finely grated rind of 1 lemon
a blade of mace or 1/2 teaspoon nutmeg
1 teaspoon ground cinnamon
5 oz granulated sugar
1-2 tablespoons brandy or few drops of brandy flavouring
1 tablespoon arrowroot
2 tablespoons water
whipping cream, to serve

Method

  1. Sprinkle the lemon juice over the peeled pears, then stand them in a large saucepan.
  2. Pour in sufficient water to make a depth of 1 inch in the pan. Add the grated lemon rind, mace and ground cinnamon.
  3. Cover and bring to the boil, then reduce the heat and simmer for 20 minutes.
  4. Put the sugar in a heavy-based saucepan and allow to caramelize to a light golden colour over a low heat. Remove the saucepan from the heat and cool slightly.
  5. Remove the pears carefully with a perforated spoon and reserve them. Pour the cooking liquid from the pears on to the caramel in the saucepan. Using a wooden spoon, loosen the caramel and dissolve it over a gentle heat.
  6. Place the pears in the caramel liquid and add the brandy. Bring to the boil, then reduce the heat. Cover the pan and cook for a further 10 minutes.
  7. Remove the pears with a perforated spoon and place them on a serving dish.
  8. Blend the arrowroot with the water, then add to the caramel liquid. Bring to the boil, stirring all the time. Simmer for 2 minutes, then pour over the pears and serve at once with whipped cream.

Makes 6 servings.

Source: The Encyclopedia if Creative Cooking


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