Abnormal Pectoralis Minor Muscle and Evidence of Modified Axillary Arch

The muscle is thin and triangular in shape, situated at the upper part of thorax deep to pectoralis major and arises from the upper margin and outer surfaces of 3rd, 4th and 5th rib (frequently 2nd, 3rd and 4th) near the cartilage and the fascia covering intercostalis externus muscle. The fibres pass in the direction upwards and laterally and converge to form a flat tendon and inserted into medial border and upper surface of coracoid process of scapula. But, in the body mentioned here, the muscle in question is also flat and triangular, situated in a deeper plane than the pectoralis major, supplied by the usual nerves {i.e. medial and lateral pectoral nerves) as that of usual pectoralis minor, the origin of this muscle also corresponds to the description mentioned above (figure 1, plate XVII) but the abnormality is the peculiarity in the direction of its fibres and their mode of insertion. The fibres instead of being directed upwards and laterally pass downwards and laterally andcrossing the latissiinus dorsi at the post-fold of axilla get tendinous and placed on the medial side of the