Hello i have a cramps on shoulder from back to front that comes and goes . when it happens i just freeze can't move .

Get an exam: Please see your MD for a full history and physical examination. Need a full history of the symptoms and to check for related symptoms on a review of your medical history and pertinent physical exam findings. Occupation, physical activities and many other things contribute to the differential diagnosis so please be seen. Good luck.

Not enough info!: You don't say how long you have had this, or if you hurt your arm, or changed your activity level recently. If this has gone on for more than a day or two after an injury see a doc. If you had no injury and have had pain for more than a few hours, get seen by a doc today. If you have shortness of breath or the pain lasts for more than 5 minutes at one time, get seen now! Good luck!