Baseball Throwing

Question
Hi, right now im 15 about 5'8 and play third and second base. Now i have been training with weights frequently and stretching. i would like to know if there are any training programs to gain strength to throw harder to first. And things i shouldnt do or stay away from. Also recently my friend told me i shouldpractice throwing like an infielder such as bringing my arm straight back almost like a catcher. and throwing keeping my elbow up. now since ivebeen doing that it is much eassier but idont get as much power. also i have been gettig some pain in the back of m shoulder. not the rotator cuff. also more towards going down to the top of my arm and cant get that to go away. what do you reccomend for throwing for an infieldr. throwing like a pitcher bringing it down to my waist and then throwing. or bringing it behind my head pushed back and slingin it. i just seem to struggle gettin to throw the ball on a lineto first and using my lower body to help throw instead of just allmy arm. can you help with training, shoulder pain, arm positioning, and how to build up to throw harder over to first.

thanks, nick

Answer
If you want to improve your arm strength try getting on a good long toss program at least two days a week.On the throwing motion for an infielder that is hard to say because I would need to see your throwing motion.Look up the JOB arm exercies and do those but I would say you need to go to the doctor and getr it checked out.