Two running backs played through possible concussions last week, but the NFL says no protocols were breached.

Arian Foster of the Houston Texans suffered a blow to the head and, as the medical team was preparing to examine him, left the bench and put himself back into the game. Two plays later, he was taken off and underwent an evaluation in the locker room and was cleared to go back in.

Bernard Pierce of the Jacksonville Jaguars was injured and then tried to block instead of tackle on the punt unit, but nobody noticed symptoms of head injury until after the game. The next day, it was announced that he was undergoing the concussion protocol, and the team staff found two plays on the game tape that could have been the cause.

The NFL says that both teams handled the situations correctly, and perhaps they did as well as they could have under the circumstances. But one player ignoring the possibility of a concussion and another being injured without anybody realizing show just how far we have to go in pursuit of head safety in sports.

*Scientists have no conclusive evidence as to whether or how the reduction of g-forces during impacts reduces the number or degree of concussions and head injuries. GelDefender products provide supplemental padding as well as cooling and comfort benefits when used with helmets and caps. Participants in activities in which head impacts can occur should always use tested and approved helmets for protection. However, no helmet or supplemental padding can protect the user from all serious head or neck injuries that can result from impacts.