One of the skills you need to [tag]become a baseball coach[/tag] is to learn how to treat [tag]sports injuries[/tag]. Hamstring pulls are one of the more common injuries that a [tag]baseball[/tag] [tag]coach[/tag] will need to be able to recognize and preferably to prevent through proper [tag]warm up drills[/tag] and stretching. 
Hamstring Pull
Description: The [tag]hamstring[/tag] is the group of three muscles at the back of the leg. A pull includes any tearing or stretching done to the tendons of this area. Hamstring pulls are often caused by sudden shifts in speed or beginning a sprint from a standing position. Hamstring injuries are characterized by a sharp, sudden pain in the back of the thigh that may cause sudden weakness in the area. Often, it is extremely painful to flex the leg when there is a hamstring injury.
Causes of hamstring injuries include improper stretching and conditioning, muscle fatigue, doing too much too soon, reduced flexibility, muscle imbalance between the quadriceps and the hamstring, and poor muscle strength.
In light [tag]hamstring pulls[/tag], there are microscopic tears in the muscle that cause minor bleeding in the muscle. In severe pulls, the muscle may tear completely apart, requiring surgery to repair the torn ends.
Prevention: To prevent hamstring injuries, ensure that athletes go through a proper warm-up and [tag]stretching[/tag] exercise. To stretch the hamstring, lean forward with the legs straight, aiming at touching the toes. This stretch should be held for at least 10 seconds and the athlete should not bounce or change positions during this time. Another, similar stretch happens when the athlete sits on the floor with the legs out straight. Lean forward over the legs, keeping the knees straight and reaching for the feet. The lower back should be straight on this stretch. Keeping the lower back straight focuses the stretch on the hamstring and not the back of the knee, helping you maintain good posture and stretch correctly.