Exploring the Profound Mysteries of Movement

James M. Loy, Miami University's College of Education, Health, and Society

We so often take for granted what, on the surface, appears to be the routine minutia of everyday life. The seemingly simple and commonplace act of extending an arm to pick up a cup of morning coffee, for example, would not command much consideration from most. But Dr. William Berg does not perceive the world like most people. To him, such an activity might represent the symphonic efficiency of an extremely complex system that necessitates serious academic investigation.

As Miami University professor of kinesiology in the College of Education, Health and Society, Berg studies the fundamental nature of human movement, which is at the crux of a highly complex mystery that has yet to reveal most of its secrets.

Bill Berg“To me, human movement is the most important thing we do because, as neuroscientist Daniel Wolpert has pointed out, it is the only way we have to affect the world,” says Berg. “Memory, perception, cognition, all of that eventually has to serve action. Otherwise it isn’t manifested anywhere. So what I do, what I’ve done in my career, is try to understand how we actually move, and how we learn complex and adaptable movements.”

As it turns out, this is a very hard problem to solve, especially once we consider the countless unconscious actions that the brain makes in advance of even the most basic movement. So even extending both arms straight forward, for example, is far more intricate than it might first seem.

Before even this simple movement occurs, the brain somehow prepares for the action by running a comprehensive diagnostic that triggers a series of subconscious processes. First, it considers, and accounts for, a long litany of factors such as the level of muscle fatigue, balance in relation to the body’s center of gravity, and the disruption of posture that is likely to occur.

Then, the brain anticipates the consequences by stimulating numerous muscles including the erector spinae, the glutes, the hamstrings and more, before finally enabling anterior deltoid to produce the fluid movement that actually allows a person to extend both arms forward.

This all happens nearly instantaneously, without any conscious awareness whatsoever, and, perhaps most impressively, all in harmonious synchronicity with the hundred and thousands of other much more complicated movements that most people make every single day.

“Put that in the context of real world action where you have multiple limbs moving at the same time, and perhaps multiple contradictory perturbations, or disruptions, to your posture, then you are down the rabbit hole to a complexity that we really can’t even imagine,” Berg says.

These unconscious brain responses are called “anticipatory postural adjustments.” They form the basis for much of Berg’s current work, and their relatively recent discovery is part of what makes the true nature of movement so mystifying.

“What we know about movement is significantly less than what we know about other things,” Berg says. “Several years ago, IBM’s Watson computer easily beat the best Jeopardy players, yet engineers have struggled to design and build a bipedal humanoid robot that can walk and navigate the environment any better than a very young child. Turns-out walking on two legs in a cluttered environment, something we do nearly automatically, is exceedingly complex. Relatively speaking, we don’t know very much about this thing we call ‘action.’”

Berg’s latest work focuses on how the central nervous system prepares for, processes, and performs skilled movements. But he has also studied how neuromuscular training programs affect quadriceps and hamstring muscle activation, how an object’s weight and distance influences muscles during seated reaching tasks, various aspects of anticipatory and compensatory neuromotor control functions, and much more.

Bill Berg and undergraduate studentsTo help solve these problems, Berg often enlists the help of Miami students who, as undergraduates, take an unusually involved role in his comprehensive research processes. Many of these students are kinesiology majors interested in fitness or wellness. Others have various medical-related aspirations to become physical or occupational therapists, podiatrists, or chiropractors.

But what they all have in common is an interest to explore the mysteries of human movement, which often generates an eagerness that is directly inspired by genuine enthusiasm of their professor.

“Dr. Berg taught me about his world,” says Miami alumna Kelsey Biller. “The excitement that he conveyed to the class about his research and how he became interested in the topic really struck me as exciting.”

Biller is currently a doctoral student in Ohio University's physical therapy program, where she is continuing to build upon the strong research foundation first established at Miami. Throughout her time at Miami, Biller quickly became a research assistant, a lab manager, and even a co-author for a paper published in a renowned academic journal.

Along with fellow Miami alumni Aaron Hannigan and Brian Richards, Biller worked closely with professor Berg to complete a project titled, “Does load uncertainty affect adaptation to catch training.” Published in Experimental Brain Research, the study examined the neuromotor anticipatory and compensatory aspects of catching, as well as the effects of load uncertainly on catching control, training, and improvement.

Their work has the potential to influence any number of real world applications across a variety of contexts. It could, for example, help younger adults improve anticipatory motor control functions through innovative training regimens. Or it could be used in clinical settings to rehabilitate elderly adults. Furthermore, this research, especially the process involved, is also immensely beneficial to the students themselves.

It not only affords a unique look into the science of movement, it’s also a rare opportunity for students to gain rich, in-depth, and direct research experience.

“I was part of finding participants, getting research money to fund our project, data collection, data processing, writing of the findings, and presenting the research,” says Biller. “I participated in every aspect of the research process first hand, instead of just reading about it in a book.”

By and large, this is not a typical experience for most undergraduates enrolled at many other universities. Elsewhere, this level of attention and instruction is often reserved for the graduate level. But in Miami University’s Department of Kinesiology and Health, and especially under the guidance of professor Berg, it is not at all uncommon.

“I had the opportunity to present at a major conference,” says Hannigan, who is also currently pursuing a doctorate of physical therapy at Ohio State. “I also had the chance to continue to collaborate with Dr. Berg during my graduate education for a publication. It’s extremely rare at most schools that undergraduate students have the opportunity to develop such strong relationships with their professors.”

According to Berg, many of his best researchers are undergraduates, and he often has the pleasure of working with them for several years. Together, they try to unravel the mysteries of movement in ways that are both rewarding for the students and illuminating for the discipline.

Earlier in his career, Berg studied specific issues that were more geared toward practical application. He studied falls in older adults, why it happens, and how falls can be prevented. He’s studied various physical training scenarios. And he and his students also proved that hands-free phones were no less distracting than hand-held phones while driving, and since 2003 no new legislation has since made a distinction between the two types of mobile phone usage while enacting restrictions.

Bill Berg and undergraduate studentsToday, however, Berg is more focused on the bigger picture, and his work concerning anticipatory postural adjustments often highlights just how much there is still left to learn.

“We didn’t even know we had these things called anticipatory postural adjustments until 1969. Now my students think 1969 was ancient history,” he says playfully. “But it wasn’t. So our understanding of how our brains anticipate and predict and estimate what’s going to happen is the cutting edge of understanding human motor behavior.”

Looking ahead, Berg imagines that the progress currently being made in this area could have profound implications that may sweep across most aspects of society. Advancements would significantly affect an array of athletic training programs, physical therapies, and rehabilitation techniques, and probably in ways that most experts can’t even anticipate.

“Part of the problem with certain movement disorders -- or perhaps even developmental disabilities, learning disabilities, or learning problems -- might be that anticipatory system,” Berg explains. “So if that anticipatory system doesn’t work, one would expect our movements to be ineffective, uncoordinated, maybe even painful. So there might be some possibility for different rehabilitations or preventions if we understood more about how the system worked.”

Other implications could also impact neuroscience, evolutionary biology, physics, and engineering.

Even the most advanced modern humanoid robots, for example, are only cable of mimicking basic human movements, and that’s about it so far. They may be able to move from one place to another, or perform the exact same motion again and again and again in a highly previse manor. But engineers are still struggling with making a robot that is dexterous and adaptable.

“It is hard to simulate human behavior, when you don’t understand human behavior,” Berg explains. “So one of the reasons humanoid robots aren’t very effective right now is because we have not figured how to build in that anticipatory function. We don’t yet understand precisely how we do it. So understanding how our own system works could lead to advancements in technology.”

Even further down the road, the potential for dramatic innovation and understanding is exciting to consider, and nearly limitless. It is not a stretch to imagine how future breakthroughs could produce significantly improved prediction capabilities in driverless cars or highly adaptable androids.

Eventually, we could learn how humans might better adapt to extraterrestrial environments, or evolve to move in new ones. And some experts, such as neuroscientist Daniel Wolpert, even speculate that cracking the code of movement will be akin to understanding the fundamental nature of the brain itself, which, Wolpert argues, first evolved to control movement long before it developed thoughts and feelings.

It may be strange to think that something like movement, which to many people may seem so common and so mundane, belies such an intricate complexity that is, so far, nearly unfathomable.

Perhaps this is only because, so very often, these types of deep and penetrating mysteries are typically pondered on a scale of cosmological grandeur. But in reality, just as perplexing as our ultimate place in the universe, it seems, is to consider the intimate mystery of how we actually move so fluidly through it.