The term ARTHROGRYPOSIS, from the Greek "arthr" = joint and "grip" = bent, is not a singe, defined disease, but rather a description of clinical symptoms characterised by various congenital, that is apparent after birth, configurations of concentrates of the limbs. These are generally non-progressive and often exhibit gradual improvement with proper treatment.
The basic factor which leads to prenatal stiffening of the joints is lack of fetal movement (akinesia). Fetal movement begins to appear in healthy individuals around the 8th week of gestation. Absence of movement of the fetus (fetal akinesia) which lasts only three weeks may be enough to cause the incorrect extension of the muscles and tendons which affect the joints, and thus cause a loss of elasticity in the joint capsules and ligaments, leading to these becoming fibrous and stiffening in the passive position of the limbs while in the womb.