Nicole Wetsman, Author at ��è��Ƶ

The way we run protects our upper bodies but our legs suffer

Nicole Wetsman — Thu, 29 Jun 2017 14:45:29 +0000

Legs bear the brunt

Jonathan Knowles/Getty

Love a good run, but keep getting leg injuries? That could be because the way we run puts the brunt of jogging’s hard impact shocks on our lower limbs.

The average recreational runner usually clocks between 150 and 170 steps a minute. This means that in a light, half-hour run, your feet will strike the ground around 5000 times. “Every time your foot hits the ground, your body absorbs the impact,” says at the University of Nevada, Las Vegas.

To study how these vibrations affect our bodies, Delphine Chadefaux at Aix-Marseille University in France and her colleagues used high-speed cameras, leg sensors and force-sensing plates to follow motion, acceleration, muscle activity and the force of hitting the ground in 10 recreational runners. Each participant ran both barefoot and in shoes, and at two different speeds.

Together, these techniques enabled the researchers to home in on where the leg absorbs the impact energy from running. They found that the foot unsurprisingly absorbed the largest part, and the energy then decreased upwards through the tibia (shinbone) and knee. This was particularly pronounced in barefoot running, which produced almost four times the amount of shock energy in the foot as running in shoes.

Preventing injuries

However, in both barefoot and shoe-wearing runners, the team found that the impact shocks had almost entirely dispersed by the time they reached the hip.

Chadefaux, who presented her findings today at a conference of the Acoustical Society of America in Boston, Massachusetts, thinks this suggests that the way we use our muscles when we run is geared towards protecting the upper body from impact vibrations.

She and her team think understanding how the body does this might lead to ways to reduce shock in the lower part of the leg, and prevent common injuries such as stress fractures and joint problems.

Runners get injured because the constant, repetitive shocks can wear on bones and joints. “If you have too many impacts and the bone does not have a chance to recover, that can lead to a stress fracture or some other issue,” says Mercer.

He says the team’s methods are a lot more specialised and focused than previous attempts to understand the impact of running, and could improve understanding of the effects of jogging-induced shock vibrations.

Chadefaux now plans to look at how different muscle activity might control the impact of foot strikes. Using a different type of shoe or changing how a person runs might help prevent injuries, she says.

Try these simple mental tests to see if you’re a good athlete

Nicole Wetsman — Mon, 27 Feb 2017 10:48:40 +0000

Top of their game

Quinn Rooney - FIFA/FIFA via Getty

Simple mental tests may be able to identify people who are likely to reach the top of their sport. That’s according to researchers who showed that elite athletes who play team sports aren’t just stronger and faster than the rest of us – some of their cognitive skills are better, too. Young soccer players, competing at the top level in Sweden, performed better than the general population on tests of so-called “executive function”. And the better their results, the more goals they scored. Executive function isn’t a measure of intelligence – it describes unconscious mental abilities like our working memory, which is involved in manipulating transient information to help us make decisions, and attentional control, which is our ability to choose what to pay attention to and what to ignore. You can test aspects of your own executive function by taking two simple tests, such as the and the . In the first test, you will see words like “red” written in different coloured inks. Your task is to name the colour of the ink rather than read out the word. It tests your brain’s ability to inhibit certain learned responses and your ability to focus for long periods of time.

Mental flexibility

The second test measures your brain’s processing speed, visual search speed and mental flexibility by getting you to draw a line between ascending numbers spread randomly on a page. Torbjörn Vestberg at the Karolinska Institute in Stockholm, Sweden, and his colleagues carried out these tests and others on 49 players from an elite soccer academy in Sweden. All of the participants were under 20 years of age. Even after controlling for other factors that could affect their performance on the field, the athletes who had higher scores of executive function netted more goals over a two-year period. According to Vestberg, skills associated with executive function match up with what is required of soccer players and other athletes. “When you’re more successful in soccer, you have cognitive flexibility, you can shift focus, you can suppress behaviour, you can be creative and find solutions very fast,” he says. Vestberg and his group had previously that executive function correlated with success in adult soccer players, but this new study showed the same tests could predict success in young players too – even though their executive function skills might not be as fully developed. Most executive functions take place in the frontal lobes of the brain, which don’t finish developing until a person is in their late teens or early twenties. It makes sense for athletes competing at the highest level to have these enhanced mental abilities, based on the actions they need to take on the field, says at the University of Montreal, Canada. “It’s on the fly decision making,” he says. “Reading all the input, taking all that in and acting on it does require some fundamental cognitive capacities.”

Predicting success

Faubert has in professional soccer, hockey and rugby players, and found – like Vestberg – that athletes performed above the general population. The effect has also been found in . Cognitive tests might help coaches identify “late bloomers”, says Vestberg – those youngsters who might start off smaller physically, putting them at a disadvantage against their larger peers, but who have the cognitive profile to grow to be successful athletes later on. The tests might also help players and coaches find areas of weakness and so design strategies to compensate, or to identify which position on the field a player should take. “For instance, you might have a different sort of cognitive profile if you’re a striker, midfielder or a defender,” says Vestberg. This research doesn’t answer the nature versus nurture question – it isn’t clear if the cognitive skill in athletes is innate, or if it is a result of training, says Faubert. But the research helps tease out the things that make elite athletes special. “We’re trying to build a notion of what the make-up of an elite athlete is,” says Faubert. “You can’t just look at physical attributes, and you can’t only use their knowledge of the game. Knowledge of the game is critical, but how well you make decisions, that’s when you can compete.”

PLoS One

Concussed athletes more likely to injure their legs months later

Nicole Wetsman — Fri, 13 Jan 2017 15:32:53 +0000

Fit for action?

Mark LoMoglio/Icon Sportswire via Getty Images

Head injuries are more than just a headache. Athletes who get concussed are more likely to later tear a knee ligament or sprain their ankle – and stiffer hips and looser legs may be to blame.

Sportsmen who have an of getting a musculoskeletal injury in their for up to three months after the head injury. “We knew they were more likely to get hurt but we didn’t know why,” says at the University of Florida, in Gainesville.

To find out, her team examined 39 college American football players. Of these, 13 went on to have head injuries. DuBose and her colleagues discovered that for an average of 50 days after a head injury, these athletes had stiffer hips, but looser knees and legs.

“Stiffness is one of those ‘Goldilocks’ measures: too much is not a good thing, too little and you’re not stabilising your lower extremity,” says , a member of the team.

Return to play

The athletes’ altered limb stiffness could be a sign of changes in muscle control prompted by a concussion, but what causes this is unclear. One theory is that concussion has lingering effects on the brain areas involved in movement, even after other symptoms have gone.

“I think some part of brain processing, disrupted by the concussion, affects your motor programming, which leads to problems in muscle activation and consequently your movement pattern,” says team member . “When you have an altered movement pattern, that can make you at risk for injury.”

Problems in other brain systems, like vision, might also increase athlete injury risk, says at the University of Wisconsin, in Madison. But she warns that the underlying relationship between concussion and other injuries is unclear. “How do we know these athletes weren’t different to begin with? Maybe the reason they got a concussion in the first place is that there’s something different about them,” she says.

Even so, the association between concussion, stiffness and injury may ultimately lead to changes in how athletes recover from concussion. They may need to undergo more thorough assessment of their muscular control and meet stricter health criteria before being allowed to play again, says Herman.

Medicine & Science in Sports & Exercise

Nicole Wetsman, Author at ��è����Ƶ