I fell & landed on my shoulder, i feel pain in muscles behind my shoulder when i try to raise my arm in a certain position, a bit swollen what is it?

Shoulder trauma: from a fall can cause a fracture, a sprain of the acromioclavicular joint, a dislocation or subluxation of the glenohmeral joint, a soft tissue injury of the inside or outside muscles of the shoulder or of the large muscles in the neck the attach near the shoulder and many other more detailed injuries, or can cause bruising pain and swelling. if pain & motion is an issue seek evaluation in person