The axillary arch: anatomy and suggested clinical manifestations.

The purpose of this commentary is to describe bilateral anomalous bands of the latissimus dorsi muscle observed in an 81-year-old male embalmed cadaver, and to discuss the possible clinical implications of this anomaly. The musculotendinous bands tautened and compressed the underlying axillary vessels, and the musculocutaneous, median, and ulnar nerves during passive abduction/external rotation of the shoulder. Similar variations found in the latissimus dorsi muscles in this commentary have been reported in the anatomical and surgical literature.

Brachial plexus paresis associated with fetal neck compression from forceps.

Instrumental vaginal deliveries have been associated with higher risks of brachial plexus injuries. The proposed mechanisms involve the indirect association of instrumental deliveries with shoulder dystocia and nerve stretch injuries secondary to rotations of 90 degrees or more. We present a brachial plexus paresis resulting from direct compression of the forceps blade in the fetal neck.