The fragile boy looks as if he could just slip from his mother's arms with a strong wind.

He weighs 17 pounds.

And he doesn't talk yet, except for babbling noises.

Right now he is clinging tightly to his mother's neck, whimpering softly and burying his head in her shoulder while a horse named Dixie is led out of a nearby barn.

Trevor, who has a genetic disorder so rare doctors don't know how it will affect his development, comes here to work. And he knows it.

As a therapist gently pulls Trevor from his mother's arms and carries him toward the horse, he raises a small, pale hand over the woman's shoulder toward his mother, mustering the strength to cry just a little bit louder.

Many sessions at Paulding County's McKenna Farms Horse Therapy start with tears.

On top of a horse, with a riding helmet constantly sliding down over his sparkling green eyes and soft blond hair, he looks even more vulnerable.

This Dallas boy is among dozens of kids with disabilities who visit McKenna Farms each week. Opened two years ago, McKenna Farms is among just a handful of hippotherapy providers in Georgia.

Hippotherapy -- physical and occupational therapy while riding a horse -- is a unique opportunity for kids like Trevor -- children who have disabilities such as cerebral palsy, Down syndrome, autism and multiple sclerosis.

The combination of the horse's gait, which echoes the way humans walk, and the relaxed setting -- a barn or riding ring -- sometimes allows children intimidated by a clinical setting to make remarkable strides with speech, motor skills, posture and balance.

For each therapy patient at McKenna Farms and for each watching parent, there's so much drama in their weekly sessions, so much struggle, joy and accomplishment.

Small steps that many other parents may take for granted are enormous victories here: sitting up straight, learning to say the words "go" or "stop" to the horse, riding while letting go with one hand -- then two.

More than 30 children's names are on a waiting list for McKenna Farms, all hoping for the opportunity to try this therapy, which by many accounts is remarkably successful.

For Trevor and his mother, Kim Nice, it was just a few weeks before the tears gave way to sheer delight.

After just two sessions on a horse, Trevor did something he had never done before. A boy who could walk only while holding on to a wall or clinging to a railing walked independently for the first time. He and his mother were sitting on the floor playing when Trevor stood up and just wobbled away one day. He made it all the way across the living room.

"I called everyone I knew," his mom said.

How horses aid therapy

The term hippotherapy is from the Greek word hippos for horse and literally means treatment with the help of a horse.

The three-dimensional, repetitive movement of the horse, combined with the unique environment, distinguishes it from traditional therapy. The horse acts as a mobile therapeutic tool. The animal's body movement, coupled with traditional physical and occupational therapy, influences a patient's muscle tone, mobilizes joints, activates muscle action and improves balance.

It is often covered by insurance and is widely recognized by the medical community.

Dr. Evan Brockman, a Hiram pediatrician, has been referring patients to McKenna Farms for three years.

"Horseback riding is exercise. You have to sit astride, maintain balance and posture. When a child is on a horse, that repetitive, rhythmic movement is sensory input. A child has to respond to the movement of the horse to maintain their balance, and over time it works the child's muscles," Brockman explained.

"It's really catching on nationwide," she added. "Every single child I've referred [for hippotherapy] has improved."

For nearly two years after their son was born, Kristen and Tim Maxwell's lives were limited to safe terrain.

They didn't go on vacations. They didn't go to the beach or the park. And only rarely did they go on picnics.

Their son Sam has Down syndrome, making outings with him somewhat difficult.

At the annual Easter egg hunt organized by the Maxwells' extended family, Kristen and Tim had to learn to juggle to keep up.

"One of us would carry the basket. The other would carry him, and we would have to bend over with him to get eggs," she continued. "By the time we would get around, there were hardly any eggs left."

Life has changed dramatically for the Maxwells since Sam started hippotherapy. He has two sessions weekly, one with a physical therapist and the other with an occupational therapist.

The physical therapist addresses fine motor skills and upper body coordination. The occupational therapist focuses on stretching, strengthening, gait and stability.

Initially the therapy was emotionally and physically exhausting for Sam.

Kristen had to walk alongside the horse during the first few visits, singing nursery rhymes to soothe and comfort Sam, who was scared. Other times he was so fatigued by the exercises he actually fell asleep on the horse.

But that has changed now. On a recent day Sam stood in front of his mother, squirming out of her grasp, anxious to get on the horse.

Jesse Moore, the farm's 29-year-old executive director, announced Sam would be riding a horse named Blue.

"Blue," repeated Sam, in a voice as soft and light as talcum powder.

A few minutes later he was sitting atop Blue, holding a ball in the air while the horse paused beside a basketball hoop.

While on the horse, patients go through a variety of activities geared toward their specific needs, goals and disability. Activities include ring tosses, basketball, stretches backward and forward, riding backward and riding hands-free. Each exercise works a specific muscle or improves eye-hand coordination, speech or other skills.

Sam tossed a basketball through the air and it swished through the net.

He was overjoyed. The sessions also build a child's confidence.

"Yeaaaaah!!" Sam said, clapping wildly and giggling.

After about a year of hippotherapy sessions, Sam began walking on his own. He's also talking more now.

The Maxwells are also spending more time outside these days. Last spring they even spent four days in Florida, at the beach. Sam was able, for the first time, to walk on his own in the sand.

"He loved it. He absolutely loved it," Maxwell said of that trip. "The breeze, the water. It was so therapeutic for him. Hippotherapy has opened up a whole new world to him."

At the end of every session, the children are asked to brush the horse a few times. For some, who are tired or have sensory issues that make them afraid of touching the horse, one or two strokes with the brush is all they can manage.

When Sam dismounted from Blue, he started enthusiastically brushing the animal.

One. Two. Three. Four. Five strokes.

That was more than any other patient who had visited on that day, and everyone was excited.

Sam ran to his mother and said proudly, "I do it!"

Then he tore off, running excitedly in zigzags. He stopped, turned back toward the crowd watching him and grinned while thrusting his chest out.

This from a boy who couldn't walk before he started hippotherapy.

"We're so afraid his first sentence is going to be 'I want a horse,' " Kristen Maxwell said, laughing.

Sometimes a struggle

Things can be tough here, though.

For Dale Tyson, 8, there is still some struggle.

Tyson has cerebral palsy, and he hasn't progressed quite as far as Sam.

"What do you tell McKenna, Dale?"

"Go," the Marietta child says softly.

"Sit up tall, Dale. I don't want to have to hold you up," says Moore.

Children who have a lifelong disability typically spend two years in hippotherapy. Goals are set for each child to accomplish during that time.

Dale's goals are trunk and head control.

The doctor who referred Dale here would like him to sit up straight on his own -- for 20 seconds. Right now he can do it for only five seconds.

"So he's got a little while to go," says Moore.

Today Dale appears more tired than usual.

He and Moore are playing a dice game, one of the activities used to prompt speech and motor skills.

A large, fuzzy die is thrown on the floor of the barn and Dale is supposed to tell the horse to walk the same number of steps as the number the die lands on.

First, number one comes up.

"Tell McKenna to take one step," Moore urges Dale softly.

Silence.

Again a die is thrown.

It lands on four.

Dale smiles at Jesse.

He looks down at the ground.

And again there is silence.

The therapist gives up on this game and moves on.

Dale does some activities quite well but grows tired during others.

But when it comes time at the end of the session to brush the horse, Dale starts crying and flailing about. Elliot Barham, the family friend who accompanies Dale to his weekly therapy sessions, steps in.

"Come on, do it, Dale, then we can go," he says gently.

"We'll just do it two times," Moore adds. "That's not hard."

Dale cries louder.

Moore compromises. She holds Dale's hand in hers and helps him stroke the horse with the brush.

They manage two strokes this way.

"That wasn't so bad," she says.

Barham scoops Dale up in his arms and hugs him close.

Dale stops crying immediately. And as Barham turns to walk away, Dale, peering back over his shoulder at the horse, is smiling.

"You did good today," Barham says softly. "You did good."