This bone lies externally on the side of the little finger. The ulnar process is the attachment of the triceps brachii muscle (m. triceps brachii). The superficial flexor muscle of the fingers (m. flexor digitorum superficialis) is attached to the coronoid process. The brachial muscle (m. brachialis) attaches to the ulnar tuberosity (tuberositas ulnae). In the upper part of the shaft, the initial attachment of the invertor muscle (m. supinator) is attached. The deep flexor muscle of the fingers (m. flexor digitorum profundus) is attached to two-thirds of the shaft. The pronator quadratus muscle (m. pronator quadratus) is located on the front surface of the shaft, closer to the distal edge. The long abductor muscle of the thumb (m. abductor pollicis longus) and the extensor muscle of the index finger (m. extensor indicis) are attached to the back of the shaft.