Background and Objectives. Regional anesthesia of the upper extremity may be achieved by the infraclavicular approach to the brachial plexus.

Methods. Advantages of this approach include profound anesthesia of the upper extremity with minimal risk of complications.

Results. Isolated block of the musculocutaneous nerve may result by this approach if biceps muscle contractions are accepted as evidence of brachial plexus location by peripheral nerve stimulation.

Conclusions. Stimulation of the musculocutaneous nerve in the infraclavicular region results in biceps muscle contraction. Inadequate anesthesia of the upper extremity may result due to exiting of the musculocutaneous nerve outside the axillary sheath in this region. Evidence of more distal stimulation (finger/wrist flexion) improves the likelihood of successful block of the brachial plexus by the infraclavicular route.