A former soldier battling PTSD was forced to crawl to the finish line of the Boston marathon after his legs gave way.

Micah Herndon, from Tallmadge, Ohio, served in Afghanistan in 2010 and ran the 26.2 miles in three hours and 38 minutes to remember three comrades he lost in combat.

But at mile 22 his legs gave way and Micah was forced to slowly and painfully crawl across the finish line.

Micah Herndon, from Tallmadge, Ohio, served in Afghanistan in 2010 and ran the 26.2 miles to remember three comrades he lost in combat

Micah Herndon with his wife Sarah. As soon as he reached the end of the marathon, he was lifted in to a wheelchair and given medical attention

Mr Herndon lost three comrades while fighting in Afghanistan in 2010

And while other runners who passed by celebrated crossing the finish line the pained but determined expression on Micah's face showed a very different experience.

As soon as he reached the end of the marathon, he was lifted in to a wheelchair and given medical attention.

Micah ran with the names of the men lost during the attack in Afghanistan on tags on his running shoes. Mark Juarez, Matthew ballard and Rupert Hamer died in 2010.

And as he ran he said their names in his head to keep him going.

'I run in honor 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.'

Micah ran with the names of the men lost during the attack in Afghanistan on tags on his running shoes. Mark Juarez, Matthew ballard and Rupert Hamer died in 2010

Micah crossed the finish line with a time of three hours and 38 minutes after he was forced to slow to a crawl by the end of the race

Damage to their vehicle after it was hit. Micah crossed the finish line with a time of three hours and 38 minutes after he was forced to slow to a crawl by the end of the race

Micah was the gunner of the convoy. This meant he was often exposed to sand, dust and grit

'I feel like if I am not running, then I am doing something wrong with my life.

'If I get a heat cramp while running or my feet hurt or I am getting exhausted, I just keep saying their names out loud to myself.

'They went through much worse, so I run for them and their families.'

Micah crossed the finish line with a time of three hours and 38 minutes after he was forced to slow to a crawl by the end of the race.

'Determination and grit at its best. War and athletic hero' wrote the filmer who shot the video from the finishing stands.