AITAH for calling myself (18F) disabled in front of a disabled person?

Two weeks ago, I started an internship at a data analytics firm. Apparently at the beginning of every summer they hold a BBQ to welcome the new interns and give them a chance to get to know everyone outside of work. The BBQ was held at my bosses house and about 25 people were expected to come. My boss had set up a volleyball net and after everyone was finished eating, people started teaming up and heading over to play.

One of my coworkers asked me to join their team, but I politely declined. I explained that I have a disability and couldn’t play. I didn’t explain much further because the disability that I have is an extremely rare genetic disorder that is difficult to explain, so I usually just keep it pretty bare-minimum. If people want to ask about it, they always do.

Well, one of my other coworkers is disabled and uses a wheelchair. She was close enough nearby to hear what I said and shot me a real dirty look when I said I had a disability. She said that there was no possible way I had a disability, because she sees that I walk fine and have no observable impairments. This caught me a little off guard, because I have never had anyone question whether I was truly disabled or not.

I explained to her that I was born with a genetic deformity, and that the bones in my legs had formed incorrectly. I told her that I had many surgeries growing up, and I was in the hospital so often that I had to do school online. She asked me why I even needed those surgeries, so I explained that my knees dislocate very easily and I had difficult walking without popping a knee out. So I spent 7 years having surgeries and in recovery to get me to the point where I could walk again.

But, I can’t do a lot of things that others can. I can’t run. I can’t jump. I can’t pivot easily, and I definitely can’t play sports. I always joke that if my life depended on it I could run, but I wouldn’t make it more than a block. She argued with me back and forth and said that my condition isn’t really a disability. I feel really bad. I have always classified it as a disability, because I don’t know what else to call it. I never thought that it would be offensive to others. Either way, my coworker stormed off and I decided to just go home. So AITAH for calling myself disabled in front of my disabled coworker?

Edit: wow, thank you for all of your support. Im so grateful to read all of your personal experiences with this issue and I wish you all the best. I will be using the term “invisible disability” going forward because it is important to spread awareness about them 🙂