Posture in utero can be responsible for changes other than the ones of bone which have been so long recognized. Blood vessels can be affected by posture. The pressing of one fetal part upon another may affect them, as may continued contact against the uterine wall, and, rarely, a blood vessel may be so altered in its course by the extension of a leg, for example, after birth, which had been held in a rotated position, as to kink the vessel. Paralysis, too, can result from posture, through direct pressure on a nerve, perhaps, or certainly through interference with its blood supply.
Most nerves are protected from pressure by their location within the body. The laryngeal nerve is an exception to this. Its branches are peculiarly vulnerable to damage from posture because they enter the larynx through narrow spaces between movable cartilages and bones. One enters above and the other