Development of feedback and feedforward control of upright stance.

Feedback and feedforward (anticipatory) adjustments of stance were investigated in 58 children with normal development aged between seven months and 14 years, and in 14 children with motor and mental retardation aged between 21 months and seven years. Feedback responses after tilting the body were elicited in all but the two youngest children, aged seven and nine months. The observed rapid decrease in feedback response latency with age suggests considerable acceleration of central transmission. Effective anticipatory postural adjustments (feedforward) were elicited only in the normal children over four years of age. The development of both feedback and feedforward continued until adolescence.