Abstract: Objective To investigate the effects of hip and knee flexion exercise on pain-related factors in patients with lumbar disc herniation after minimally invasive treatment. Methods Total 294 cases of lumbar disc herniation in our hospital between March,2010 and March,2015 were enrolled and randomly divided into observation group and control group with 147 cases in each group.All patients underwent transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion (PLIF) therapy,postoperative straight leg raising exercise and lumbodorsal muscles exercises;the observation group received additional hip and knee flexion exercise.The pain and pain-related factors before and after the treatment in two groups were compared. Results VAS score and the levels of MMP-3,IL-1,IL-6 and TNF-alpha at d1,d7 and d14 after the operation were significantly reduced in both groups,and VAS score and pain-related factors levels at d7 after the operation in the observation group were significantly lower than those in the control group (P<0.05);there were no significant difference in VAS score and pain-related factors levels before the operation,at d1 and d14 after the operation between the two groups (P>0.05).JOA score at d1 and d7 after the operation increased significantly in both groups,and JOA score at d7 and d14 in the observation group were significantly higher than control group (P<0.05);there were no significant difference in JOA score before the operation,at d1 after the operation between the two groups (P>0.05).Three months after the operation,the total effective rate was 85% in the observation group,which was higher than that (66.7%) in the control group (P<0.05). Conclusion Hip and knee flexion exercise can reduce the postoperative pain in patients with lumbar disc herniation after minimally invasive treatment,and decrease pain-related factors levels,improve the outcome of patients.It is worthy of clinical promotion.