EE states while working on 09/21 pulling & prying heavy objects EE noticed left shoulder was sore, employee continued to work through shift. On 09/22 EE noticed shoulder continued to be sore. While attempting to lift heavy objects on 09/23 EE experienced increasing pain in left shoulder. EE went to onsite clinic for OTC med. On 9/26 MD placed EE on modified work due to soreness.