The transverse head of adductor hallucis.

91 human cadaver feet were dissected to reveal the transverse head of adductor hallucis and measurements of the weights, angles of pull, width of origin and insertions were recorded. The origins and insertions of this muscle were found to differ from standard textbook descriptions. The origin usually includes the deep transverse metatarsal ligaments of the foot, the plantar ligaments of the lateral metatarsophalangeal joints, the intermuscular septa of the third and fourth muscle layers and the fibular syndesmosis of HENKEL (1913). The insertion was found to be usually by fleshy attachment to the lateral border of the oblique head of adductor hallucia. The angle of pull and the adjusted weights (% of intrinsic muscle mass) were found to be highly variable. In addition the transverse head was absent in 6% of the specimens. The function of this muscle is in question and it is likely that it is of little importance in normal foot functions.