Steven Muck put on his riding helmet, stood thoughtfully on the mounting ramp, then carefully mounted Amigo, a specially trained horse at Rainbow Therapeutic Riding Center in Haymarket.

The Forest Park High School student sat in the saddle for a few minutes surrounded by a team of instructors, side walkers and his special education teacher, MaryAnn O’Brien.

He had promised himself the week before that he would mount the 16-year-old chestnut quarter horse.

He was encouraged to take a few steps, but that would wait for another day: Muck said he was taking baby steps.

When he dismounted, O’Brien was waiting for him with a high-five.

Sitting on Amigo was a huge step for Muck, who is one of 63 Forest Park special education students with autism or intellectual and physical disabilities participating in a new equine program funded by a grant from Potomac Health Foundation.

O’Brien was originally looking for a therapeutic riding center where she could take her students on a field trip.

As a Prince William County school’s special ed teacher, she faces issues such as limited opportunities for therapeutic recreation and affordability, she said.

After talking with Debi Alexander, executive director of Rainbow Center, they decided to join forces last spring and write a grant application for “The Mane Experience,” a project to serve Forest Park students who have physical and intellectual disabilities.

The Potomac Health Foundation awarded the $69,000 grant in September, and the first session began Oct. 3. The program is divided into three seven-week sessions.

Once a week, three groups of seven students take a bus from Forest Park in Woodbridge to the riding center in Haymarket, where they rotate through three stations: riding, ground work and grooming.

Therapeutic riding helps build physical strength. It also builds confidence as students learn to overcome their fears and anxiety.

During the ground work rotation, students learn to maneuver the horses with verbal and physical cues. They also learn to read the horse’s body language, such as lip-licking and tail flipping.

“They’re speaking the horses’ language and learning to communicate with horses in a way the horses understand, so they can please you,” O’Brien said.

Because horses are sensitive creatures, students need to establish dominance so the horses feel safe and protected, Alexander said. “It’s incredibly empowering for the students,” she said.

Ground work also provides an opportunity for students to encourage and support each other.

Ashley Tayon, O’Brien’s assistant, reminded student Lauren Orlinsky to “walk with confidence” as she led Kia around the ring. Orlinsky strutted back to the group to claps and cheers.

Tayon said she has seen positive changes in her students — not just in relationships, but with motor skills, too. “I get excited for horse days,” she said.

Back at the grooming station, students learn about responsibilities around the farm. They learn to groom, bathe and care for the horses. They’re learning vocational skills and about specific jobs.

“I want to come here every single day,” Carlos Diaz said. “I want to work here, too.”

The program doesn’t end when the students leave the center. They write in their journals about their experiences, create simulations on Smartboards and use videocameras to produce a documentary.

“This is one of those tools that has had a huge impact,” O’Brien said. “Their abilities are limitless.”