Anterior shoulder pain is a very common injury I see and treat in bodybuilders. There are several different reasons for this, one is due to the excessive load/volume they put on the front deltoid during training. Bench press, front raises, military press, and push-ups are frequently trained movements that target the front portion of the shoulder muscle or Anterior Deltoid. This is usually the intention of the athlete.
However, I often see the Anterior Deltoid being overused in movements which should not target that region so much. The lateral dumbbell raise is a great example. This exercise generally involves the athlete raising the arms out to the side remaining in the frontal plane. Performed this way the primary focus will be on the most lateral portion of the deltoid. When the athlete starts bringing the arms forward in an attempt to lift heavier weights, the primary tissue targeted shifts to the Anterior Deltoid.
A simple fix is to perform the exercise in front of a wall which provides the feedback to keep the arms in the frontal plane. This will ensure that the primary tissue involved is the lateral aspect of the deltoid.