Superficial branch of the radial nerve emerging between two slips of a split brachioradialis muscle tendon: a variation of possible clinical relevance.

One hundred and fifty upper extremities of 75 nonrandomized human cadavers were dissected to study the topographical relationship between the brachioradialis muscle tendon (BRMT) and the superficial branch of the radial nerve (SBRN). A split BRMT was found in nine arms, while in five of those nine arms the SBRN emerged from under the brachioradialis muscle between the two slips of a divided BRMT to become superficial. This topographical relationship is mentioned sparsely in very old literature, yet its frequency has not been studied before.