William Wilson has been walking with a cane since 2015. Over time, the physical stress resulting from two back surgeries, two knee replacements, and a new ankle left the 69-year-old struggling with hyperextension and maintaining control over his movements when walking.

On Tuesday, Wilson stepped into a pair of “space shorts” – made of a wetsuit-type material that zips around the waist to create an airtight seal – and onto an anti-gravity treadmill that uses differential air pressure developed by NASA. The setup allows patients to defy gravity during physical therapy sessions, which helps them build strength without pain.

A pocket at the bottom of the anti-gravity treadmill fills the shorts with air up to the user’s waist and offers reverse pressure, supporting patients at up to 80 percent of their body weight. The method was developed in the late 1980s as a way for astronauts to exercise in space, as the zero-gravity environment caused weight loss, muscle atrophy, and decreased bone density in those remaining in space for prolonged periods of time.

“One of the most functional things we do as human beings is walk,” said Dr. Jordan Mazick, physical therapist at the HealthLink Fitness and Wellness Center with the Baptist Health System. Wilson is a more complex patient who benefits from this therapy; it also can be used for people with ankle sprains, Achilles tendon repairs, ACL reconstruction surgeries, and for people who suffered a stroke or other neurological issues, Mazick said.

When Wilson stepped into the suit and onto the treadmill, physical therapists instructed him to watch the screen in front of him, which shifted between a view of his knees and one of his feet as he walked. The goal of the exercise is for patients to pay attention to their gait, how their feet fall, and stabilizing their movements.

“It hurts some, and when I am done here, I am tired,” Wilson said. He uses the anti-gravity treadmill in addition to more traditional physical therapy, including strengthening exercises, he said.

An AlterG treadmill can cost up to $75,000; the one located at the Baptist Emergency Hospital is a rental, and it is being used for physical therapy, sports performance training, and people with mobility issues.

According to the Centers for Disease Control and Prevention, 17 million adults in the U.S are either unable or find it very difficult to walk a quarter mile. Sixteen percent of adults have physical functioning difficulty.

Organizations throughout San Antonio offer anti-gravity treadmills as part of physical therapy and wellness programming, including the D.R. Semmes Family YMCA, which has one available for use by its members.

“No one wants to depend on a walker to get around,” Wilson said. “I want to be able to walk on the beach and catch some fish without help.”

Roseanna Garza

Roseanna Garza

Roseanna Garza reports on health and bioscience for the San Antonio Report.