Story highlights Jimmy Carter and Christina Aguilera are among those recognized

Ali appears at the event in his hometown along with his wife and daughter

It was the inaugural Muhammad Ali Humanitarian Awards

"This is really about his legacy and extending that legacy to others," Ali's wife says

Appearing very frail, boxing legend Muhammad Ali made a rare public appearance Thursday at an event in his hometown to pay homage to others for their humanitarian work.

Former President Jimmy Carter, music artists and young leaders of groups helping the underprivileged were among those honored at the inaugural Muhammad Ali Humanitarian Awards in Louisville.

Even though he was barely able to whisper a word, Ali posed for pictures and participated in presenting the awards.

"This is really about his legacy and extending that legacy to others and inspiring them and encouraging them to do the kinds of work that now he cannot always do himself," Ali's wife, Lonnie Ali, said at the gala.

While Parkinson's disease has robbed the three-time world heavyweight champion of many of the traits he once treasured in the ring -- the speed, wit and charisma that made him one of the most famous sports figures in recent history -- he has never retreated from public life.

'His head is still there'

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"People always feed bad when they see my dad, and I feel bad because he has Parkinson's disease and it's hard for him to get around, but he is happy," said his daughter Laila Ali, who retired undefeated as a super middle weight champion. "His head is still there, and all we can do is keep loving him and supporting him even though it's never easy to watch."

Recipients of the Muhammad Ali Humanitarian Awards included 22-year-old Tanvi Girotra of India, who leads a global youth organization that seeks to combat sex trafficking and empower women.

Walking along the red carpet to greet Ali, 71, was 15-year-old Nick Lowinger of Rhode Island, who began outreach work with homeless people at the age of 5.

Lowinger was recognized for his foundation, which provided shoes to more than 10,000 homeless and disadvantaged children in 21 states.

"Nobody had to asked them to do it, they recognized the need and they jumped to action just to recognize that somebody needed something," said Lonnie Ali.

Carter, who turned 89 on Tuesday, was singled out for a lifetime achievement award. The 39th U.S. president was unable to attend, so his son James "Chip" Carter accepted the award.

Pop stars recognized

Pop singer Christina Aguilera received the humanitarian of the year award for her work on global hunger relief, while her fellow recording artist Michael Bolton was honored for his work promoting gender equality.

The awards were established in conjunction with Ali's core principles of conviction, dedication and giving, which are illustrated at the Muhammad Ali Center, a museum that also chronicles his epic boxing matches, the struggle for racial equality and his conscientious objection to the Vietnam War that eventually cost him his titles and millions of dollars in endorsements.

Over the past four decades, Ali has visited more than 100 countries, providing humanitarian assistance and at times mediating in international disputes, notably in situations where U.S. citizens were held captive in Iran and Iraq.

"He has a body of work he has done traveling the globe, helping others by bringing assistance and aid to those who are in need," said Lonnie Ali. "And he wants to extend that part of life to others by recognizing their support and serving as an encouragement."

While Parkinson's disease has taken a severe toll on Ali, his wife says his commitment to social justice has not wavered.

"Every day he gets up with a smile in his face and looks forward to whatever the day brings," she said. "He doesn't let things stop him and he does as much as he can every day and he still finds meaning in life."