Recent research studied the effects of ankle foot orthotics on trunk postural control and lower limb coordination in 20 children (ages 4-12) with and without cerebral palsy.  The results of tridimensional trunk kinematics and thigh, shank, and foot elevation angles while walking barefoot and with ankle foot orthotics indicated the following

• significantly greater trunk excursions in children with cerebral palsy compared to
  typically developing children in both conditions
• when wearing ankle foot orthotics, increased trunk frontal angular velocity was seen in children with cerebral palsy whereas typically developing children showed increased trunk frontal displacement
• no significant changes in trunk displacement and angular velocity were recorded in the sagittal plane in either group
• significant changes in shank and foot elevation was seen in both groups when wearing the ankle foot orthotics

Reference: Degelean M, De Borre L, Salvia P, Pelc K, Kerckhofs E, De Meirleir L, Cheron G, Dan B. Effect of ankle-foot orthoses on trunk sway and lower limb intersegmental coordination in children with bilateral cerebral palsy. J Pediatr Rehabil Med. 2012 Jan 1;5(3):171-9.