http://www.ncbi.nlm.nih.gov/pubmed/24030309 

Abstract: Bicycling injuries can be classified into bicycle contact, traumatic, and overuse injuries. Despite the popularity of cycling, there are few scientific studies regarding injuries.
Epidemiological studies are difficult to compare due to different methodologies and the
diverse population of cyclists studied. There are only three studies conducted on top level professionals.

Ninety-four percent of professionals in 1 year have experienced at least one overuse injury.
Most overuse injuries are mild with limited time off the bike. The most common site of overuse injury is the knee, and the most common site of traumatic injury is the shoulder, with the clavicle having the most common fracture. Many overuse and bicycle contact ailments are relieved with simple bike adjustments.