as many as possible 200,000 people in the United States strain or tear their anterior cruciate ligaments each year. And tears rising between young athletes. The factors involved are numerous. For prevention, the researchers focused primarily on the physical. Although with some success – prevention programs can reduce The risk of knee injury is more than 50 percent In sports like football that require high-speed sprinting and slashing back and forth – non-contact ACL injuries still occur, even in very strong and physically fit athletes.
Cognitive input, physical movement
Physical factors, such as the extent to which the knee flexes and collapses inward during landing and cutting activities and hip and leg strength, are controlled and affected by the complex interaction between the brain and peripheral nerves. Emerging research suggests that how the brain processes these sensory and cognitive inputs may influence movement patterns that increase injury risk—in other words, better and more efficient processing may translate into less risky movement.
The movement begins and continues with a plan. Instead of coordinating every movement in real time, neuroscience experts believe that the brain is constantly planning one step forward.
says Dustin Grooms, a neuroscientist and athletic trainer and Professor of Physical Therapy at Ohio University.
After initial planning and decision making, the motor cortex sends impulse to the muscles to execute the movement, Grooms says. “If all goes according to plan, when the brain’s sensory predictions match the environment and the movements occur as predicted by the brain, you get an efficient neural response that keeps the body moving, without any excessive brain activity.”
But if your integration of what you see and proprioception (the sensation that tells you where your joints are in space) malfunction, beware. And if the prediction error is too great, the cerebellum — the part of the brain that controls movement — can’t correct fast enough.
In this case, Grooms says, areas of the brain that are normally used to aid spatial processing, navigation, and multisensory integration are redirected to control only one part of the body, like a leg for example. With so many competing demands — such as during a competitive game — the brain may not be able to correct a knee or ankle malfunction in the fractions of a second it takes to tear a ligament.
“When you start putting athletes into dual-task scenarios or in unforeseen circumstances, you start to see some of these risky mechanisms become more apparent,” says Jason Avidian, a biomechanics expert and director of sports science for Olympic sports at Clemson University. The question becomes, “Does [athletes] Dedicating enough attention to what is appropriate versus what is not appropriate? “
Although it is difficult for researchers to replicate the dynamic, high-speed conditions athletes encounter in the laboratory, One recent study Attempted to identify differences in brain activity in knee control between high- and low-risk athletes.
Neurological competence and risk of injury
Researchers led by Grooms, in combination with functional magnetic resonance imaging of the brain, analyzed the knee mechanics of a group of female high school soccer players. When the movement is involved in A jump landing from a 12-inch box was analyzed, They found that areas of the brain normally responsible for combining visual information with attention and body posture showed elevated activity in athletes with more severe knee mechanics.
In a sense, the riskier group was borrowing brain power from cognitive processing areas to coordinate movement. That becomes a problem when these athletes are trying to navigate a complex sporting environment, such as trying to dribble a defender on the soccer field.
Essentially, people who showed lower efficiency in their neural processing were more likely to exhibit risky mechanisms.
“Everyday tasks and athletic environments require us to balance motor and cognitive demands as we process and process information from our environment to inform how we move,” says Scott Monfort, researcher and co-director of the Neuromuscular Biomechanics Laboratory at Montana State University. .
“How well we pick up on and respond to appropriate cues can affect how effectively and safely we move, whether that’s making our way down a busy street or trying to evade an opponent during a sport,” he says.
Monfort studies how biomechanics tend to be more dangerous when movement is done with an added cognitive constraint, such as dodging an opponent.
his researchwhich was published in the American Journal of Sports Medicine, investigated how cognitive ability relates to neuromuscular control in a group of 15 soccer players.
In addition to a cognitive assessment of visual and verbal memory, reaction time, and processing speed, subjects were asked to perform consecutive 45-degree trials with or without a football dribbling. Knee position during cutting movements was evaluated and analyzed.
The researchers found that poor visuospatial memory was associated with more dangerous knee mechanics while dribbling the ball, when there were additional requirements for tracking and planning the movement of the soccer ball.
While the research indicates a higher risk of injury when neural efficiency decreases during dynamic movement, the relationship may exist the other way as well. knee injury or ankle It may alter neuromuscular control, further affecting the risk of reinfection.
More recent collaborative research by Monfort He and Groom found more pronounced differences in single-leg balance when subjects who had anterior cruciate ligament reconstruction had to identify and remember information displayed on a screen in front of them.
What has not yet been determined, however, is the significance of cognitive-motor function in sports injuries, and how this may vary by age, level of experience, or through genes.
“There is some evidence that more experienced athletes can show better performance on tasks that require balancing cognitive and motor demands as well as on isolated tests of cognitive abilities,” says Monfort.
Monfort says he believes training under conditions that mirror real-world scenarios, which include simultaneous cognitive and motor demands, “may improve the potential for benefit from real-world performance.”
One of the obstacles to recovery from injury or surgery may come from the rehabilitation programs themselves.
“Our rehab may promote this neurological compensation strategy — staring and thinking at the quadriceps muscle — when instead we need to think about the progression of this neurological aspect of rehab. [attention, sensory processing, visual-cognition] In addition to typical strength,” says Grooms.
Enhancing processing skills could be as simple as asking athletes to respond to visual stimuli — such as adding numbers on flash cards or moving in response to different colored lights — while jumping or jumping side to side.
Grooms say that sports and even most activities of daily living create unique demands on the nervous system, and standard exercise programs may prime the muscles but not the nervous system.
“We’re really good at thinking about what the joints should be doing, what the muscles should be doing,” says Grooms. “But we should try to think about what the nervous system has to do and how it might need to adapt and adapt to the demand on it.”