I have never tried yoga, so I arrived for a class at Triyoga in Chelsea feeling pretty intimidated. My inner cynic expected sinewy people standing on their heads in a fug of incense, but instead I find a large white room scattered with purple mats, foam bricks, blankets and other participants. I choose a space and sit on a mat on the floor.

When our teacher, Matthew Sanford, arrives he lays a calming hand on my shoulder and in a soft American voice describes me as sporty and determined to the point of bloodymindedness. He recognises this, because I am on the floor with my wheelchair parked next to me – and we are both paraplegic.

Sanford was just 13 when his family's car hit a patch of ice and slid down an embankment. His mother and brother survived, but his father and sister were both killed. Asleep at the time of the accident, he suffered a broken neck and back, among other injuries. He was in a coma for three days.

"I was a very athletic kid, and I loved feeling my whole body," he tells me. "After the accident, doctors told me I didn't have sensation and I believed them. They called the tingling and burning in my legs phantom feeling, in case I took it to mean I would walk again." Actually, as I know myself, the constant "noise" in my legs, which can be anything from an almost pleasant, warm tingling to excruciating pain, may not be functional, but it is certainly real.

Sanford duly followed the traditional approach to rehabilitation: "I learned to make my upper torso really strong to overcome my body. That's a metaphor for everything, because you can't overcome your body."

Then, 12 years after the accident, Sanford was in graduate school studying philosophy when he met a yoga teacher. "We explored what the principles of yoga meant for a mind-body relationship such as mine. I started to feel that [phantom] sensation again, and I thought: 'I belong here. I can't do the poses like everyone else but I can feel the wholeness that is at the core of the poses.' That's the true heart of yoga."

Now he is passionate about passing on what he has learned to other teachers and recently travelled to the UK to run a series of workshops to spread the message that yoga can be perfect for people with disabilities. "I got lucky because I found a great teacher, so I want others to find a yoga teacher to work with. The principles of yoga don't discriminate, but the poses do. That's a big distinction. When I realised that the principles of alignment and precision are in every yoga pose, I knew that I could teach anyone.

"It was scary as hell, though. Even now, when people have signed up for a class and they realise their teacher's in a wheelchair, they give me a look that says: 'How?' But I start working them and after five minutes they forget."

Sanford also teaches healthcare professionals. "There are a lot of areas of healthcare where people need to be more [aware of] their bodies. As people age they lose connection and physical strength, and can start falling. We have to teach them this other level of sensation too, one that isn't just about physical achievement, because they shouldn't be running on a treadmill any more. I can't do cartwheels any more. That time in my life is over.

"Just because you can't stand up, and you can't feel me tickle the bottom of your feet? It just means that tickling your feet isn't a good way for me to teach you to be in your body. I have to get you to do different things, but it's going to make you feel more whole, in a practical, real, way. That wholeness is essential for your long-term health. It's never going to make you walk again. It's not going to reverse your condition. But moving with your whole body is something that everyone needs, especially someone with a disability."

The session I attend is hard; the focus on precision and balance requires concentration and physical control. The class is a mixture of yoga teachers, and first-timers. Of the novices, three of us are wheelchair users, and one is living with partial paralysis following a stroke. Sanford's methods for adapting yoga to suit the individual are often ingenious. We use folding chairs, foam blocks, belts and even other participants to help us find the "core" of the poses. By the end of the 90-minute class I am sitting unsupported on the floor with my arms above my head and my legs outstretched. This is extremely difficult when paralysed from the waist down. I have no fixed "base" as I cannot gain stability from my buttocks or thighs, but somehow I am spreading myself out to my heels as much as the tips of my fingers. Instead of trying to balance on nothing, I feel like I am grounded on something firm and tangible.

I don't "feel" my legs as I did before my spinal-cord injury, but I am aware of them in a way that I haven't been since my accident six years ago.