Shoulder pain release point

my son was getting a little shoulder pain,and his control was off,I took him to the doctor to make sure he was okay and then worked on his release point,control never came back and shoulder pain was still there,I then took him to former pro pitcher,the shoulder pain and release point was caused by the same problem,his lead foot was opening up to soon causing him to throw across his body,that was causing the shoulder pain,and his release point,the ball was cutting instead of getting the normal spin, my advice is to let someone teach your kid how to pitch the proper way for health reasons and so they can pitch in the years to come.