The future of movement
Nearly 15 years ago, an idea struck NAU Regent’s Professor Dr.
Kiisa Nishikawa that would fundamentally change our understanding of muscle
function. Today, that idea has turned into the winding filament hypothesis—a
theory that will more accurately demonstrate how muscles work.
Nishikawa and her interdisciplinary team of NAU professors
believe this research has numerous implications, including everything from improved
prosthetic devices to neuromuscular disease treatment. Nishikawa’s groundbreaking theory has shown so much
potential that it has captured the interest of the W.M. Keck Foundation, who
recently made a $1 million investment to further explore her hypothesis.
The titin effect
Nishikawa’s theory supplements the most widely accepted
theory used to explain muscle contraction, which dates back to the 1950s. The
current sliding filament hypothesis looks at the interaction of two proteins in
muscles, actin and myosin; however, Nishikawa explains, this theory can’t
predict the force a muscle should produce when interactions with the
environment cause it to stretch or shorten.
Nishikawa’s winding filament hypothesis solves this problem
by including another protein in the equation: titin. When titin is factored in,
muscle force output can be accurately predicted. When this force can be
predicted, the fields of medicine, bioengineering, and robotics can be drastically
Nishikawa is very optimistic about the uses of her research.
One of her team’s primary goals is to create a motor that will make prosthetic
devices move more like real limbs.
Current motorized prostheses are controlled by computer
algorithms that are more robotic than biological. Nishikawa believes a
muscle-like actuator will make it easier for disabled patients to adapt to prosthetic
limbs. Additionally, prostheses used to enhance able-bodied people, such as
soldiers on a battlefield, will be more intuitive.
“Our brains expect our bodies to be moved by muscles, not by
motors, so theoretically the prosthetics will be easier to learn how to use,” Nishikawa
She also believes that a better understanding of muscles
could help treat neuromuscular diseases.
“Symptoms of diseases like Parkinson’s are caused by the
interaction between the nerve and the muscle,” she says. “If we can better
understand what a muscle does when the nerve is activated, then we could also create
therapies to alleviate those symptoms.”
Nishikawa’s groundbreaking research was recognized by the W.M. Keck Foundation, who awarded her a highly prestigious $1 million dollar grant. These grants are endowed to only the most
innovative researchers in medicine, science, and engineering—only six institutions
received grants in the medical research category in 2014. Nishikawa and her
team were honored to be chosen for awards.
The university will benefit from this grant long after Nishikawa
has completed her research. The money is being spent on new, state-of-the-art technologies that will advance scientific inquiries at the university, including an atomic force microscope and updates to an electron microscope. Nishikawa believes these technologies will ultimately benefit students by offering expanded
research opportunities and attracting more world-class faculty.
“With this new equipment, we’ll support younger faculty and
their efforts to perform cutting-edge research with students at NAU,” Nishikawa
says. “My research is only the beginning.”