"Tears and hugs, matching tattoos and pictures, storytelling and encouragement," Gaga, 29, captioned the backstage photo. "These survivors represented for others all over the world and I was so honored to be up there with them. 50+me= 51 #tilithappenstoyou."
The Grammy winner performed her and Diane Warren's Oscar-nominated song "Til It Happens to You" at the 88th Academy Awards in L.A. on Sunday, February 28. The ballad was written for the documentary The Hunting Ground, which is about campus rape.
During Gaga's powerful set, 50 women and men (some of whom were featured in the film) joined her on stage. Some had words written on their arms, such as "Not Your Fault" and "Unbreakable."
The Hunting Ground producer Amy Ziering opened up about the emotional performance a day after the star-studded show. "It was an idea that the music supervisor Bonnie Greenberg, me, Lady Gaga and Diane Warren all had," she told Entertainment Weekly. "Wouldn’t it be powerful if the survivors in the film performed?"
Many of the audience members teared up while watching the group on stage. Afterward, during a commercial break, Room actress Brie Larson — who would later win in the best leading actress category — hugged each survivor as they walked past her seat. (Larson, 26, plays a sexually abused victim in Room.)
Back in 2014, Gaga opened up about her own "horrific" sexual experience, giving vague details during an interview with Howard Stern.
"I'm able to laugh now because I've gone through a lot of mental and physical therapy and emotional therapy to heal over the years. My music's been wonderful for me. But, you know, I was a shell of my former self at one point. I was not myself," she said at the time. "To be fair, I was about 19 … I went to Catholic school, and then all this crazy stuff happened, and I was going, 'Oh, is this just the way adults are?'"
"It happens every day, and it's really scary and it's sad. And you know, it didn't affect me as much right after as it did about four or five years later," she continued. "It hit me so hard. I was so traumatized by it that I was like, just keep going. I just had to get out of there."
Watch Gaga's Oscar performance in the video above.
Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!