MONSTA X's Shownu suffered from a sudden, unexpected injury during the December 14 broadcast of MBC's 'Real Men 300'. 

On this episode, the new recruits of the army's White Skull division finished up their physical ability tests, then took part in grenade throwing training. The new recruits struggled not only with throwing the grenade into the designated area, but also with the correct directions on how to throw the grenade. VIXX's Ravi was first to make a mistake, his grenade going off in mid-air. When Shownu stepped up for his turn a few minutes after, he made the same mistake as Ravi, earning a sharp scolding from the trainer. 

After making his mistake, Shownu decided to give the grenade throwing a second time. However, in an attempt to do his best, Shownu threw the grenade as hard as he could - too hard, that his arm popped out. 

Shownu immediately reported his situation to the trainer, and his fellow soldiers rushed to help examine his shoulder. By the end of the episode, the idol was seen heading in for a proper medical examination. 

Make sure to tune in to next week's 'Real Men 300' to see if Shownu was able to recover and return to training.