Free the ulnar nerve from the triceps muscle and retract it medially;then separate the triceps from the posterior surface of the medial intermuscular septum and the adjacent humeral shaft.

• 从肱三头肌处游离出尺神经，向内侧牵开，然后从内侧肌间隔的后方表面临近肱骨干处分离肱三头肌。