Sung KH, et al. – Physicians designed this study to assess the outcomes after distal hamstring lengthening (DHL) and examine the factors that influence the improvement and serial change in knee motion after surgery in patients with cerebral palsy (CP), using a linear mixed model (LMM). As a part of a single–event multilevel surgery (SEMLS), medial hamstring lengthening with semitendinosus transfer was an effective procedure in treating flexed knee gait with regard to sagittal knee kinematics and gait deviation index (GDI) score in spastic CP with flexed knee gait.