The cubital bone, also known as the ulna, is a major component of the human forearm. This long bone runs parallel to the radius, supporting the forearm and enabling movement of the elbow joint. Although commonly referred to as the cubital bone, it is crucial to note that this bone is synonymous with the ulna. The term "cubital bone" is often used interchangeably to describe the ulna, both medically and informally. This strong bone plays a vital role in maintaining the stability of the forearm and facilitating necessary actions like flexing and extending the arm.