Iron Soles

The Iron Soles (アイアンソール) are support items invented by Mei Hatsume for Izuku Midoriya's hero costume.

Description
The Iron Soles were created by Mei to act as armor or cleats. They are an important part of Izuku's hero costume upgrade because they allow him to compensate for his leg strength. This was key to allowing Izuku to develop his Shoot Style fighting technique because it maximizes the strength of his kicks.

Whenever Izuku delivers a kick and the soles receive a forceful impact, the toes of the soles spring out in a blowback motion to give Izuku's attacks a powerful double impact. This gives Izuku's kicks enough force to create shock waves and break through solid rock.

This also allows him to deal with the recoil from his kicks, lessening the force that rebounds on him.