Posterior wall of the axilla is formed by all of the following muscles, EXCEPT:

Posterior wall of axilla consists of teres major, subscapularis and latissimus dorsi. The impoant relations of the posterior wall are subscapular vessels, subscapular and thoracodorsal nerves and posterior or subscapular lymph nodes. The posterior axillary fold is formed by the teres major and latissimus dorsi muscles and it becomes prominent when the arm is adducted against resistance. Anterior wall of the axilla consists of pectoralis major, pectoralis minor, clavipectoral fascia, and subclavius muscle. The lateral thoracic vessels and anterior or pectoral group of lymph nodes are present inside this wall. Ref: Clinical Anatomy: (a Problem Solving Approach) By Kulkarni page 94.