<P> Repeated concussions have been linked to a variety of neurological disorders among athletes, including CTE, Alzheimer's Disease, Parkinsonism and Amyotrophic lateral sclerosis (ALS). </P> <P> It is estimated that as many as 1.6 - 3.8 million concussions occur in the US per year in competitive sports and recreational activities; this is a rough estimate, since as many as 50% of concussions go unreported . Concussions occur in all sports with the highest incidence in American football, hockey, rugby, soccer, and basketball . In addition to concussions caused by a single severe impact, multiple minor impacts may also cause brain injury . </P> <Table> Injury rate per exposure based on sport in collegiate athletes from 1998 to 2004 <Tr> <Th> Sport </Th> <Th> Injury rate per 1,000 athletic exposures </Th> </Tr> <Tr> <Td> Women's ice hockey </Td> <Td> 0.91 </Td> </Tr> <Tr> <Td> Men's spring football (American) </Td> <Td> 0.54 </Td> </Tr> <Tr> <Td> Men's ice hockey </Td> <Td> 0.41 </Td> </Tr> <Tr> <Td> Women's soccer </Td> <Td> 0.41 </Td> </Tr> <Tr> <Td> Men's football (American) </Td> <Td> 0.40 </Td> </Tr> <Tr> <Td> Men's soccer </Td> <Td> 0.28 </Td> </Tr> <Tr> <Td> Men's lacrosse </Td> <Td> 0.25 </Td> </Tr> <Tr> <Td> Women's lacrosse </Td> <Td> 0.25 </Td> </Tr> <Tr> <Td> Men's wrestling </Td> <Td> 0.25 </Td> </Tr> <Tr> <Td> Women's basketball </Td> <Td> 0.22 </Td> </Tr> <Tr> <Td> Women's field hockey </Td> <Td> 0.18 </Td> </Tr> <Tr> <Td> Men's basketball </Td> <Td> 0.16 </Td> </Tr> <Tr> <Td> Women's gymnastics </Td> <Td> 0.16 </Td> </Tr> <Tr> <Td> Women's softball </Td> <Td> 0.14 </Td> </Tr> <Tr> <Td> Women's volleyball </Td> <Td> 0.09 </Td> </Tr> <Tr> <Td> Men's baseball </Td> <Td> 0.07 </Td> </Tr> <Tr> <Td> All sports </Td> <Td> 0.28 </Td> </Tr> </Table> <Tr> <Th> Sport </Th> <Th> Injury rate per 1,000 athletic exposures </Th> </Tr>

What sport has the most concussions in the world