A man with skateboarding injuries but normal x-rays

A 20-year-old man was skateboarding home while carrying some takeaway food when he fell off his skateboard. In an attempt to save his takeaway, he kept his right arm in the air, landing on his left shoulder. Two hours later, after having dinner at home, he presented to the emergency department reporting left shoulder and rib pain with decreased range of movement in his left shoulder. He had pain associated with inspiration.

The man was a tradesman and had previously been well, was taking no medications and had no reported allergies.