Isaac Lau pushes his wheelchair forward, throws a punch into the air and utters an emphatic grunt to cap off his martial arts performance, as the crowd of more than 100 erupts into applause.

Lau suffers from a rare nervous disorder known as cerebellar ataxia, which affects his balance and coordination. But the disability didn't stop the 25-year-old Hawai'i Kai resident from winning a gold medal in his division in the Korean martial art of hapkido.

"Many of these kids have been told they cannot do a lot of things because of their disability," said Marty Williams, Lau's instructor.

"This is something they can do. It gives them a sense of empowerment, self-esteem and achievement."

Lau was one of more than 50 participants from Hawai'i, California and Texas who took part in the International "Specially Challenged" Martial Arts Championship at Saint Louis School's McCabe Gym yesterday.

The tournament, sponsored by the United Cerebral Palsy Association of Hawai'i and the nonprofit Abilities Unlimited, which provides vocational support for the disabled, is one of the few — if not only — national martial arts events of its kind for disabled individuals.

About 15 local residents took part in yesterday's tournament and all are Williams' students at the Abilities Unlimited Martial Arts Academy on Ke'eaumoku Street, which is Hawai'i's only martial arts school for the disabled.

"To have a venue like this for these athletes to compete in — disabled or not — is very empowering," said Daria Loy-Goto, a volunteer at yesterday's event.

Akira Etherington is one who has benefited from his involvement in martial arts.

The 38-year-old Honolulu resident, who has Down syndrome, was among the first disabled students to begin studying hapkido with Williams eight years ago. Etherington is now a red belt, a step below black belt in hapkido, said his caregiver, Nadine Santiago.

According to Santiago, Etherington's self-confidence and social and communications skills blossomed after he took up martial arts. Santiago said the classes give him the opportunity to interact with other people with similar disabilities.

"He's not afraid of being who he is," said Santiago.

Eric Rooney, who suffers from a disorder similar to autism called Asperger's syndrome, also has seen his self-esteem and self-discipline soar after he began attending Williams' once-a-week hapkido classes, said his father Scott Rooney of 'Ewa Beach

The elder Rooney said many of his 21-year-old son's classmates face similar day-to-day challenges due to their disabilities and they serve as a support group.

"It's been an eye-opening experience for him because he now sees he can accomplish things he never thought he could accomplish," said Scott Rooney.

"If everybody had as much determination or focus as these people do, this world would be a better place."

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.