 [ Symptoms ] i have pain in the chest palpitations and my left hand hurts [ Disease ] no it would not if you want to throw a wiffle ball a tennis ball or even a cotton ball for the fun of it just do it it will not damage your shoulder any more than any other repetitive throwing repeated throwing of anything however could damage your shoulder over time if you are not careful and well conditioned you need to strengthen those shoulder muscles lift some light weights do some stretchingrange of motion activities and get the proper rest between throwing i am not sure what kind of ball you are throwing i suspect a baseball but stay on top of your game