A Colles fracture is a break in the radius bone, one of the forearm bones near the wrist. The fracture usually occurs if you fall onto your outstretched hand.1 Upon landing on your hand, the end of your radius bone breaks off and gets pushed toward your inner wrist. If you fall on your hand and the wrist is flexed, the radius may break and move toward the front of your wrist. This is called a Smith's fracture.
Source: Verywell Health