The deformity of scapula alata or winged scapula caused by paralysis of the posterior thoracic nerve, resulting from trauma, presents a problem of particular interest to men engaged in practice that necessitates the assignment of the rôle of trauma in the production of paralyses alleged to be produced by mechanical injury. The treatment of this condition also deserves particular attention.
Isolated traumatic paralysis of the serratus is generally stated to be much more frequent in men than in women; according to Berger, it is eight times as common in the former, and according to Gowers, it is six times as frequent. These investigators tabulated the reports of about thirty cases from the literature. It occurs most frequently in laborers, in muscular persons during the active period of life, between 25 and 45 years of age. The reason that it is most frequent during this period, and that a predilection is