Amyoplasia is a condition characterized by a generalized lack of newborn muscular development and growth. It is the most common form of arthrogryposis, a condition that results in stiff joints and the fixed flexion (bent position) of the joints due to abnormal muscle development or shortened muscles. In amyoplasia, the normal skeletal muscle is replaced by dense fibrous tissue and fat. Individuals with amyoplasia typically have involvement of the major joints including, elbows, knees, shoulder, hips, wrists and feet. There is no one single factor or specific genetic factora that causes amyoplasia, but the condition is thought to occur when there is a lack of movement of the baby in the mother’s womb. Mothers of affected children may report that their baby was unusually still during pregnancy. This may be due to the mother having a small womb or having a lack of fluids inside the womb for the baby to move freely. Because amyoplasia is considered a sporadic (happens by chance) condition, there is a very low recurrence risk for siblings of an affected child. Corrective surgery may be performed early, at around one year of age, to fix this condition. People with amyoplasia have a good long-term outlook as their difficulties can be overcome through physical therapy, occupational therapy, or surgery. Some may continue to need special braces or support to walk. If your child has been diagnoses with amyoplasia, talk with you pediatrician about the most current treatment options. Support groups are also a good source of information and can help you connect with other families dealing with amyoplasia.