From a Conversation to a Movement: The Story Behind TandemStride
By Matt Kalina, Founder & CEO, TandemStride
When my older brother Mark lost both of his legs in a train accident in 2012, our lives changed forever. I was a senior in college at the time, working part-time at the Ohio Statehouse and sharing the same campus as Mark. We were close—not just brothers, but best friends who had lived together in college, played sports, and joined the same fraternity. Mark had always been the kind of person who made everyone feel like a fast friend. That didn’t change after the accident. But just about everything else did.
I remember walking into his hospital room after getting the call and not fully understanding the extent of his injuries until I saw him. He had lost both legs. And yet, what struck me more than the trauma of it all was Mark’s attitude. He was calm. Grounded. Focused on making us feel okay. That’s just who he is.
As our family began to process what had happened, we were also thrust into a maze of decisions and logistics. Where would Mark live? How would we make the house accessible? What care would he need? What insurance hurdles were coming? There was no roadmap. It felt like we were building the plane while flying it—grateful he was alive, but overwhelmed by everything that came after.
We were lucky in a lot of ways. My mom is a nurse. My dad’s friends built a wheelchair ramp. Friends and family rallied. But I kept thinking: What if we didn’t have all that? What happens to the families who don’t?
In those early days, what helped Mark the most wasn’t a clinical expert or a guidebook—it was a conversation. A friend of a friend, a veteran amputee, talked to Mark about what it was like to live through it. To date, to travel, to drive, to rebuild. That one conversation did more for Mark than weeks of Googling or follow-up appointments. That was the moment the idea for TandemStride first took shape.
Over the next several years, our family started the Mark Kalina Jr. Foundation to help other trauma survivors access resources and adaptive devices. We kept hearing the same things from people: “I felt alone.” “I didn’t know where to turn.” “I didn’t know what came next.”
TandemStride was built for that gap.
Today, TandemStride is a national platform that connects trauma survivors and caregivers with trained peer mentors who’ve been there. It’s not about replacing clinical care—it’s about complementing it. We help people navigate the emotional, social, and practical realities of recovery—the part that starts after the hospital doors close.
We now support thousands of survivors across the country, with over 100 trauma centers planning to adopt TandemStride in the next year through our partnership with the American Trauma Society. Our users are people like Mark. Our mentors are people like Mark.
The platform continues to evolve, now including behavioral health support, care coordination, and access to social services. But the heart of it hasn’t changed: Real people, connecting over real experience, at exactly the moment it’s needed.
When I see a trauma survivor message their mentor for the first time, I think about that night in 2012. About my brother. About the thousands of others navigating something equally life-changing. And about the simple truth we’ve learned over and over: Trauma changes everything. So should support.