As air inflates a bag, Steve Townsend is getting lighter and lighter. Before this device, he had been unable to run for 15 years.
"I went skiing for the first time in five years. And I'm on 70 percent less pharmaceuticals than I was a year ago," said Steve Townsend, San Francisco.
Steve was the first patient to use the Alter-G at the UCSF Therapy center. The device encases your lower body in a balloon that reduces your weight. It began as a way to restore strength to astronauts returning from long periods in weightlessness.
"We got an FDA clearance to market the device for medical use. This is the first time that a patient is able to control their body weight precisely," said Lars Barfod, Alter-G CEO.
"The reason that I like the body weight with air as opposed to the harness is your upper limbs are free. You can use them, you feel comfortable, you feel like you can run," said Nancy Byl, UCSF Therapy Center.
Dr. Nancy Byl is pioneering weightless training for those who find it difficult to walk, for example, after a stroke.
"In here, I feel like I'm walking in a pool -- or jello," said Susan Zieleniewicz, Piedmont.
Or who find it impossible to go aerobic, such as Sara Demirjian, recovering from brain surgery.
"It feels like I'm walking, which something I can't do normally," said Sara Demirjian, South San Francisco.
And brain training is a big component in Dr. Byl's new work. Not only are we tossing a ball back and forth, but he's reading puzzles to me, which I have to solve while I'm tossing this.
"So, I actually think it is a good bridge between a neuro and an orthopedic assistive device." said Dr. Byl.
The Oakland As, the Warriors, Stanford and Cal are now using the device for physical therapy, too.