Distal Attachment of the Brachialis Muscle: Anatomic and MRI Study in Cadavers

OBJECTIVE: The purpose of this study was to use MRI and anatomic correlation in cadavers to delineate the anatomic features of the distal attachment of the brachialis muscle. MATERIALS AND METHODS: MRI was performed on 13 cadaveric elbows. The MRI findings were compared with those in anatomic sections and histologic preparations. The brachialis muscle of one cadaver was dissected. RESULTS: The dissected brachialis muscle had two heads, superficial and deep. The attachment of the superficial head to the ulnar tuberosity was farther distal than that of the deep head. The attachments of all aspects of the muscle included a tendinous layer rather than purely muscular structures. Histologic analysis showed no direct communication between the brachialis and biceps brachii tendons or between the brachialis tendon and joint capsule. CONCLUSION: Familiarity with the anatomic features of the distal brachialis muscle and tendon is essential for accurate assessment of these structures.