The forearm is the region of the upper limb between the elbow and the wrist. The term “forearm” is used in anatomy to distinguish this area from the arm, a term that is commonly used to describe the entire upper limb. The forearm consists of 2 long bones (the radius and the ulna), the interosseous membrane, and multiple arteries, nerves, and muscles. The muscles are grouped into 2 compartments: anterior and posterior. The function of these muscles is flexion and extension of the wrist and fingers, while also contributing to flexion of the elbow.