https://www.sciencedaily.com/releases/2018/06/180601134701.htm

"We found that the number of injuries peaked early -- only about four weeks in -- and then slowly declined until the end of the season," said James Onate, associate professor of health and rehabilitation sciences at the Jameson Crane Sports Medicine Institute. "We see a lot of kids who didn't prepare in the off-season and, when their workload goes through the roof, they're not prepared for the demand of throwing."

To accurately assess the timing and severity of their pain, 97 high school pitchers were asked to submit a weekly questionnaire via text message.