An emotional and powerful video posted by Tim Siegel has garnered dozens of supportive comments.

Holding your head up straight is one of those simple things most people take for granted; it's just a part of being alive. But for Luke Siegel, who sufferd a traumatic brain injury last summer, it's a constant struggle.

The short clip above shows Luke holding his head up straight for around 12 seconds -- the longest he's done so without any help since his accident.

Tim Siegel posted about his son's accomplishment on the Pray for Luke Siegel Facebook page Thursday morning:

Yesterday at therapy they worked on his knee by trying to straighten it out. He cried out in pain.

Then helped him stand for only the third time in 8 weeks. He eventually squeezed his bottom to stand tall.

Then this.... The longest he has kept his head up with absolutely no help.

Proud. So proud.

The city of Lubbock rallied around Luke following the accident, donating more than $100,000 to a GoFundMe account created to help the Siegel family with medical expenses.

Since then, Tim Siegel has started the Team Luke Foundation. Its mission is to help children with severe and debilitating brain injuries.