Decreased limb movements are diagnosed by a discrepancy in the frequency and strength of movements between the affected and the not affected limbs. Decreased limb movements may occur because of restricted range of motion, pain, or weakness.

Decreased limb movements due to restricted range of motion during intrauterine life are characterized by limb deformity. The affected limbs have a fixed position and the examiner's efforts to change that position are met by resistance and a quick return to the original position when the limb is released. Limb deformities result from shortened muscles due to fibrosis (Figure 193.1[A]) or from arthrogryposis. Muscle fibrosis is usually associated with cutaneous scars (Figure 193.1[B]). Arthrogryposis results from asymmetrical weakness of the muscles acting upon a joint or due to a restriction in joint movement due to an aberrant sustained intrauterine position.

A	B

Figure 193.1.— Muscle fibrosis. [A] Decreased movements of the left hand, inability to fully extend the wrist and fingers, and atrophy of the distal forearm. [B] Scar on the forearm.