Background : Trunk forward bending is common in everyday life but can cause mechanical stress on the lumbar spine and cause low back pain if performed in the wrong way. Mechanical stress occurs in the lumbar spine during forward bending because of incorrect movement of the lumbar spine or hyperactivation of the erector spinae muscle. Therapeutic exercise using various auxiliary devices is necessary to reduce such stress. Objectives : The purpose of this study is to determine how visual biofeedback gluteus squeeze exercise affects the movement in the lumbar spine and the muscle activity of the erector spinae during forward bending. Methods : In this study, 25 healthy adults were selected as the subjects. During forward bending, each subject identified the information of visual biofeedback by linking a belt with a tension sensor to a mobile phone and then performing the exercise with the gluteal muscle as much as possible. The movement of the lumbar spine in forward bending before and after the performance of the exercise was compared with the muscle activity of the erector spinae to identify the effect of the visual biofeedback gluteus squeeze exercise. Results : Findings showed that the angle of the lumbar flexion was significantly higher during the forward bending performed after the visual biofeedback gluteus squeeze exercise than that without the visual biofeedback gluteus squeeze exercise. Moreover, the muscle activity of the erector spinae decreased significantly when the visual biofeedback gluteus squeeze exercise was not applied when the motion was performed in forward bending. Conclusions The results of this study confirm that the visual biofeedback gluteus squeeze exercise effectively reduces the muscle activity of the erector spinae and improves the movement of the lumbar spine during forward bending in healthy adults.