In a video teaser for its newest show, “Backbone,” the acrobats of Gravity and Other Myths can be seen stacking on top of one another like a 15-foot-tall human house of cards. This seems like it would be plenty dangerous enough without the buckets covering their heads.

The 21-member Australian physical theater company, which impressed Spoleto Festival audiences in 2014 with “A Simple Space,” returns this summer with even more awe-inspiring acrobatics in its new production.

“A Simple Space” left its acrobats sweaty, tired and fulfilled, said Gravity and Other Myths co-founder Lachlan Binns. When the company started work on “Backbone,” Binns thought maybe it would be easier. No such luck.

“We just ended up getting excited about working with more people, and the possibilities just became a little more endless,” Binns said. “And we made a show just as hard, if not harder — more impressive, more skillful, more full and longer.”

It also includes more props and other technical elements, according to Jascha Boyce, another founding member and an acrobat in the company.

“‘A Simple Space’ is exactly that, it’s a simple space,” Boyce said. “‘Backbone’ has much more of a design and set behind it, but still quite a simple design. We have rocks and sticks and buckets, normal life things. It's not like we're trying to hide behind any theater magic.”

The rehearsal period allowed the acrobats to investigate all sorts of uses for the sticks, which are solid wooden dowel rods that can suspend a human body in the air. They would then send videos of the results to “Backbone” director Darcy Grant, who would help determine what to include.

“It was a pretty similar process to doing unique creative acrobatics,” Binns said. “You’re still trying to do something that hasn't been done before — use the stick in an interesting way, the same as we try and use each other’s bodies in interesting ways.”

Some “Backbone” props are more inherently interesting than others. Rocks come into play, and the show also uses a product called granulated rubber crumb that Boyce particularly appreciates for its carpet-burn-reducing properties.

And then there’s the suit of armor.

“From the beginning,” Grant said, “‘Backbone’ was always going to be about examining strength ironically, poetically and literally, because these guys are so strong and they do so many things.”

The armor, he said, offered a visually striking way to do that, one that he was careful not to give away.

Gravity and Other Myths producer and general manager Craig Harrison said the props don’t add any more danger than the acrobats usually face when it’s time to perform death-defying feats in front of a crowd.

“Well, yeah, it’s always safe, but it’s not, you know?” Harrison said. “The things that these guys do all the time — they could die at any time, but they’ve been doing this for all their life. So hanging rocks above their head is probably one of the safest things that they do.”

Aaron Halls is a Goldring Journalist at Syracuse University.