When it comes to movement, the shear amount of power that the muscles must exert to get around often goes unrecognized.  At N.C. State, the Human Physiology of Wearable Robotics (PoWeR) laboratory on Centennial Campus is currently researching the lower half of the human body’s energy output when walking and running.  Able-bodied research

The findings from the research of the sources of lower-limb mechanical power yield many practical applications many could benefit from. There are three main target areas for applying the research findings to build assistive devices.

• Permanent Mobility Aid — For people who have had permanent nerve or muscle damage and can’t walk or run properly.

• Clinical Tool — For post-injured individuals that could recover with assisted practice.

• Performance Augmentation — For those who desire performance enhancement to become more powerful or efficient.

“We’re in the process of developing a rehabilitation center at N.C. State, and the Human PoWeR lab will form its foundation,” Sawicki said. SOURCE: Gregory Sawicki

The research is geared towards discovering the links between the mechanics and energy of locomotion, with a particular focus on the highly efficient ankle muscle-tendons and the large amounts of power they can exert.

“The big message is the power output from the ankle joints is very important when walking,” Dominic Farris, a postdoctoral researcher in biomedical engineering, said.  “When we switch to running from walking, the ankle becomes even more important.”

According to Farris, the ankle joint is of keen interest because of its role in movement, stabilization and the support of the body’s entire weight.

Gregory Sawicki, assistant professor in biomedical engineering, said the human body is set up for efficiency, and his research focuses on the physiological mechanisms responsible for that efficiency.

“People move where they tend to spend the least energy,” said Sawicki, director of the PoWeR laboratory.  “In order to increase walking speed, people tend to rely more and more on energy from their hips, but at a critical speed this is no longer as efficient, and they switch to running and produce power mainly from their ankle muscle-tendons.”

According to Farris, running allows the muscles in the ankle to contract slower, yielding high forces that can stretch the Achilles tendon, storing and returning energy.

Sophisticated technology has allowed the PoWeR laboratory to thoroughly study rapid body movements and the way the human lower-limb joints perform during walking and running in both healthy and clinical populations.

“We have an instrumental treadmill that allows us to pin-point where the mechanical output comes from in a person’s limbs,” said Farris.

Sawicki and his graduate student, Bruce Wiggin, are currently developing a prototype for a device that can store and return energy in an ankle spring, just like the Achilles tendon, so that people can move more efficiently.  They plan to begin testing the device with stroke patients near the end of the summer.

“The goal of the lab is to build a device that can help people walk and run,” Sawicki said. ”Our latest device is an ankle exoskeleton that contains springs that acts as tendons to recycle energy.  The energy is stored in the springs, which recoil and push the person forward.  And it doesn’t require any batteries or outside power source, which makes it a lightweight and unlimited source of assistance.”

According to Farris, the research can help enhance the design of prosthetic limbs. He also said the research has potential in the field of robotics.

“Many robots are biologically inspired and are designed to mimic human and animal movement,” Farris said.  “Designing a robot that could optimally run and walk would require knowledge of where the mechanical power output should come from for different speeds and gaits.”

If robotics and prosthetics is not a big enough appeal to the private sector, the researchers still have other alternative options.  With such technology on hand, there is an increasingly feasible potential to have shoes that can allow athletes to efficiently utilize their fullest amount of energy.

Additionally, Sawicki said the same technology could be applied to help soldiers on the battlefield who have to carry large pack loads and want to conserve energy.

ALT:

The findings from the research of the sources of lower-limb mechanical power yield many practical applications many could benefit from.  Currently, there are three main target areas for applying the research findings to build assistive devices.

Permanent Mobility Aid—For people who have had permanent nerve or muscle damage and can’t walk or run properly.

Clinical Tool—For post-injured individuals that could recover with assisted practice.

Performance Augmentation—For those who desire performance enhancement to become more powerful or efficient.

“We’re in the process of developing a rehabilitation center at N.C. State, and the Human PoWeR lab will form its foundation,” Sawicki said.