There's a trick to using box graters that most people don't know (I certainly didn't until recently)

• Lay a towel or some parchment paper in a sheet pan (optional)
• Lay the grater on the pan
• With your non dominant hand, hold the handle of the grater and the rim of the sheet pan
• With your dominant hand, grate, pushing away from you + into the countertop

The mechanics of pushing down/away are much better than holding the thing upright, dangling it over a bowl or whatever. Easy to just push with your palm too (and keep your fingers out of the way).