Injuries occur when stress overcomes the capacity of the joint or tissue. In pitching, increasing velocity increases the force applied to the shoulder and elbow regardless of mechanics.
The only way to combat the increase in force is to increase the size and strength of the tissue.
Muscles, tendons, and ligaments all respond to training by increasing thickness and resistance to tensile stress. As a result, when pitchers strength train, they can reduce mechanical stress. On the flip side, when muscles become weak and atrophy, stress increases due to less tissue area.