Newborn Injury

My son is now 6 months old. He has pretty bad tightness in his left shoulder/peck. I remember reading his discharge paper and the doctors notes mentioned a “thickening of the left clavicle without a definite fracture line.” He had X-rays taken of his skull but it doesn’t specify if they did one of his collarbone too. Maybe it does. Below that note, it says “2. Left midclavicular fracture versus artifact.” The doctor not once mentioned this. So I’m wondering if anyone who has had a baby with a clavicle fracture, did they have tightness? Like we’re they unable to straighten that arm over their head?