Development of the foot in prenatal life in relation to idiopathic club foot.

The development of the human foot from the eighth to the twenty-first intrauterine week was studied in 147 specimens. The results documented a stage of "physiologic club foot" characterized by a medial deviation and plantigrade orientation of talar neck and head during the ninth week. At the same time, the calcaneus assumes a position of varus with the forefoot in adduction. By the eleventh week, the foot assumes a normal position. All findings during the stage of physiologic club foot closely resemble those of the intrinsic type of club foot.