This is the second part of a two-part look at concussions: Part I

Concussions are prevalent at all levels of sports, often stalling or ending the athletic careers of professional athletes and school-age children alike. The injuries are widespread in the military, too, causing the branches to lose the services of valuable trained recruits.

It seems as though an entire industry has popped up around the affliction, exploring causes, prevention and cures. That doesn't mean there's a consensus on any aspect of concussions, though. In the Army, the definition of a concussion was clarified in 2011, resulting in Purple Hearts for soldiers who suffer the head injuries in the field.

Professional and school leagues are still trying to decide who should be responsible for determining whether players are concussed, and whether they are removed from games or practices.

Some states are pursuing legislation to make that clear. An Iowa bill, targeted at concussions, would require certified athletic trainers to be present at high school sporting events. In California, a measure would mandate that athletes suspected of suffering head injuries be benched, being allowed to return only after receiving clearance from a healthcare provider.

In Oklahoma, a state senate committee took up a measure aimed at educating trainers and athletes about concussions. In Maryland, a bill proposes suspending high school coaches who leave concussed athletes in games.

The research aims beyond sports. The U.S. military branches have seen more than 300,000 concussions in their members since 2000, and the Department of Defense is taking on research to help. Among the DoD projects is development of a blood test that could immediately diagnose a concussion. That would have applications in the field as well as on the sidelines.

According to Dr. Eric Wetzel, who leads a team working on a joint project between the Army Research Laboratory and the NFL, paratroopers suffer concussions at twice the rate of other soldiers. His team is exploring the use of tethers that would lessen extreme head motion on impact. These elements could also benefit individuals in sports that feature head-to-head contact.

Throughout the tech industry, concussions are a hot topic and growing segment of exploration in apps, tablets, sensors and eye-tracking. Numerous helmet designs have been undertaken. But that addresses only those who wear headgear, such as football and hockey players and soldiers, leaving out the soccer and basketball players who suffer the injuries.

Others are looking for ways around the injuries altogether, including alternative activities that would provide competition without the danger.

USA Football has focused on safety and training through its national Heads Up program, which trains and certifies coaches to teach proper technique and recognize and respond to head injuries, among other elements. Researchers at the University of New Hampshire explored the potential to cut down head injuries through helmetless practices.

Participation in high school football has fallen, but the game is not going away. Flag football leagues flourish, particularly for grade school-age players. In Massachusetts, 7-on-7 and 5-on-5 no-contact leagues are offered for players up to 18 years old. One editor has proposed a radical new version of the game called Clermont Rules Football, in which nine players a side can advance the ball only by passing, punting or drop-kicks, with no tackling or blocking.

There's no guarantee that any of the developments will cut down on the numbers of head injuries that soldiers and athletes suffer. But there's no question that awareness of the severity of head injuries has been raised.