Surgery planning in cerebral palsy is a complex task given the number of surgical procedures than can be combined in the same operation. Decision-making is usually based on physical examination and 3-D clinical gait analysis, but the surgery outcome remains difficult to predict. Some decision-making tools have recently been developed to predict surgery outcome (Desailly et al.,2013 ; Hicks et al.,2011 ; Reinbolt et al.,2011), but most of these predictions are whether qualitative ("good" and "bad" outcomes), or adapted to unique surgical procedures or gait patterns, which makes difficult to imagine how the patient would walk after the surgery. Galarraga et al. (2017) predicts postoperative kinematics for several surgical combinations, but the contribution of each surgical procedure is unclear. The objective of this study is to stimulate the effect of surgery on gait of children with cerebral palsy in order to predict the most likely outcome and the probable contribution of each considered surgical procedure