Aim of this prospective study is to assess the effect of posterior dynamic stabilization IntraSPINE system on sagittal spinal balance, using EOS® X-Ray imaging system. Between March and December 2015, 8 patients affected by lumbar soft stenosis underwent indirect decompression of the lumbar canal by positioning of IntraSPINE® device. Sagittal balance was evaluated considering following parameters: C7 Plum Line (C7PL), Thoracic Kyphosis (TK), Lumbar Lordosis (LL), Pelvic Tilt (PT), Pelvic Index (PI) and Sacral Slope (SS). The EOS® 2D/3D system and corresponding sterEOS 3D software for surface 3D reconstruction has been used to calculate the above mentioned parameters. All patients had neurogenic claudication and low back pain for more than 6 months and resistant to drug treatment. They underwent clinical examination before surgery and 1 month after surgery. Statistical analyses were performed using Stata software. All results were considered significant if p<0.05. C7PL, TK, LL, PI and SS were not modified after surgery. PT increased after surgery. VAS, ODI and JOA significantly increased after surgery. The results show that the posterior dynamic stabilization offered by this device leads to a good symptoms control and does not seems to change the sagittal balance.