Whenever the question comes up of whether or not head injuries sustained in the NFL are related to long-term health problems, we have to face the simple fact that there simply has not been adequate research to fully address the question. It is hard to avoid the conclusion, though, that the NFL has not made any major efforts to research the question precisely because they know that the answer is most likely not the one they would like to hear.
Many studies have shown a link between head injuries caused by playing football in the NFL and diseases like ALS. Numerous players even want compensated in regards to future diseases that may occur from playing in the NFL. Since more medical reports are continuing to find more links between the two, players are still in fear for their health in the future.
It could be said, and rightfully so, that both head injuries and ALS are associated with one another given the sport of football and the closeness of the head and neck. But both are very different and are actually apart. Head injuries are caused by exactly what you think and ALS is more spine.
There is not enough evidence to link head injuries caused by playing in the NFL and diseases like ALS. While more caution should be used when playing full contact sports, there are additional factors that act as variables as to whether or not a person will develop certain neurological diseases. To assume that there is a direct link between head injuries caused by playing in the NFL and diseases like ALS would take require additional research to back up this claim. While it is a possibility that the likelihood of players who have suffered head injuries in the NFL could be more likely to be diagnosed with diseases such as ALS, there are many people who have suffered from ALS who have never had a head injury.