American marine crawls to Boston Marathon finish in extraordinary tribute to dead servicemen

An American marine's perseverance at the Boston Marathon is being praised after he crawled across the finish line in honour of three soldiers who died in 2010.

Ohio man Micah Herndon was approaching the annual race's finish line on Tuesday (NZ Time) when his legs locked up and he stumbled to the ground.

But instead of giving up, Herndon continued on, refusing help from others and crawling to the end with a time of three hours and 38 minutes.

The run had been a special endeavour for Herndon, who was wanting to honour Mark Juarez, Matthew Ballard and Rupert Hamer - three fellow servicemen who died in 2010 during an attack in Afghanistan.

He said he regularly says their names while training.

"I run in honour of them," Herndon told the Record-Courier.

"They are not here anymore. I am here, and I am able. I am lucky to still have all my limbs. I can still be active. I find fuel in the simple idea that I can run. Some cannot."

Running has also helped Herndon deal with post-traumatic stress disorder.

"I will have setbacks in my life. I will go backwards, but it's how you respond going forward."

After finishing the race, Herndon was lifted into a wheelchair to receive medical attention, but quickly recovered.

Newshub.