Sacroiliac joint hypomobility has usually been overlooked in the management of patients with LDH and low back problems. However, there is no conclusive evidence for the effectiveness of SMT in the treatment of patients with LDH, and the evidence to date is contradictory. Therefore, the present study aimed to investigate the effect of SMT applied to the lumbar spine and SIJ to treat patients with SLDD who also had SIJ hypomobility.