The legs of a person with achondroplasia almost always become bowed and the elbows often cannot be straightened completely. Sometimes the person has limited twisting ability at the elbows. The hands are short, and the feet are short, broad, and flat. Many achondroplastic children can flex their finger, wrist, hip, and knee joints to an extreme degree because of ligamentous laxity. These signs are usually apparent at birth, and achondroplasia can be diagnosed at that time in most cases.
Intelligence is generally normal.
Affected men average 51.8 inches in height, while women average 48.6 inches. There seems to be little or no relationship between the height of the parents and the adult height of their children with achondroplasia. Related physical conditions Children with achondroplasia may reach motor milestones of development slowly. For instance, good head control may not occur until the infant is three or four months old, because it take longer to develop the muscular strength necessary to control the large head. Though there are exceptions, many of these children do not walk until relatively late, often between 24 and 36 months.