Experimental Ankle Exoskeleton Increases 40% Walking Speed

A Stanford team is working on a powered exoskeleton concept that can take up some of the physical effort
Source : medicalxpress

As people grow old , they have a tendency to walk slower. a part of this is often that they realize that there’s no point in hurrying, but there’s also the onset of neuromuscular degeneration or general wear and tear. As a result, older people and people affected by various conditions find themselves walking frustratingly slower than they’d like.

To help overcome this, the Stanford team working on powered exoskeleton concept which will take up a number of the physical effort, allowing the wearer to move faster. When complete, the device will fit round the shin and inside a running-shoe , letting the wearer to pick a preferred walking speed.

Currently, the exoskeleton is an emulator. That is, it’s an experimental setup used on a treadmill, where the exoskeleton is powered by a tether attached to large outside motors and controlled by an algorithm. Because the wearer walks, the exoskeleton acts like mechanical calf muscle, putting a small force into every step by tugging the heel upwards and pressing the toes down. This will increase the wearer’s walking speed by roughly 40%, which was unexpected.

To test the emulator, 10 young, healthy adults were asked to walk in 5 different modes in normal shoes, then the exoskeleton with power off, then with power on in 3 different modes. Two modes optimize speed and efficiency respectively, while the third was a placebo that acted as control.

As they walked on a treadmill, the algorithm adjusted the settings on the exoskeleton, optimizing it over 150 rounds, taking about 2 hours. While the speed was increased by up about 40%, energy efficiency went up only about 2%, but efficiency wasn’t the prime target for the 1st round of tests.

The immediate goal is to create the prototype more efficient and cozy . Eventually, it’ll be ready to produce an exoskeleton which will work on its own and may be worn by older people. This more advanced version won’t only improve walking speed, but also help to reduce pain from overloaded joints or imbalance.

“A 40% increase in speed is quite the difference between younger adults and older adults,” says Steve Collins, professor of mechanical engineering at Stanford. “So, it’s possible that devices like this might not only restore, but enhance self-selected walking speed for older individuals, and that’s something that we’re excited to check next.