The purpose of this study was to measure the mean peak mobilization forces to the lumbar spine 1-3 with grade III and grade IV of posteroanterior (PA) mobilization. Twenty subjects with no history of Lumbar back pain (LBP) (10 female, 10 male) with a mean age of 24.1 years (SD = 6.0) were recruited for the study and PA mobilization were performed in each spine and the therapist took approximately 2.5s to complete mobilization. In the results, applied grade IV force showed no different according to each segment in LS1, LS2, LS3, however, there are distinct differences between LS1 and LS2, LS1 and LS3 during mobilization with grade III force. This study suggested that the mean peak force of the grade III and grade IV mobilization in the L1-L3 was almost similar each other.

INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION AND CONCLUSION
 REFERENCES

• Wan Suk Choi(International University of Korea, Jinju)
• Seo Yoon Heo(Kyungbok University, Pocheon)
• Ok Kon Moon(International University of Korea, Jinju)
• Bo Kyung Kim(Howon University, Gunsan, Republic of Korea)
• Joong San Wang(Howon University, Gunsan, Republic of Korea)