Background: It is well known that squat exercises are good for scoliosis patients. Especially wall facing squat (WS) is believed to be more effective than normal squat (NS). Objectives: In order to find out what effect the wall squat has on the rehabilitation exercise of patients with lumbar scoliosis compared to the conventional squat, the force between the lumbar segments was compared using a motion analysis system. Design: Quasi-experimental study. Methods: In this work, an attempt was made to provide a scientific basis for these experiences. Inverse dynamics simulations were performed for each of the 10 subjects with mild scoliosis during NS and WS using subject-specific 3D musculoskeletal models. Exercises with three sets of five cycle for NS or WS were performed. Muscle forces calculated from the simulations were compared with electromyography data for verification. Results: The imbalance of muscle forces between the right and left in erector spinae (ES) decreased with the progress of WS sets. The difference of 14.1% for the 1st set diminished to 1.8% during the 3rd set. Conclusion: The overall level of right and left ES muscle forces also increased from the 1st set to the 3rd set. The results of simulations indicated that WS was more effective than NS for scoliosis correction.