due to industrial development and the consequent increase in daily comfort , physical 
 activities have gradually decreased , leading to increased body weight with reduced physical 
 strength , as well as more sedentary lifestyles and significantly decreased amounts of 
 exercise . due to incorrect exercise habits , even among those who exercise regularly , bad 
 posture over extended periods , and inappropriate daily life and work habits , the resulting continuous back tension has increased the 
 number of patients with low back pain1 . mennell2 presented the term joint 
 dysfunction for arthrokinematic dysfunction in the absence of pathological changes in the 
 joints , including capsules and ligaments . he also attributed muscular pain and muscle spasm 
 to difficulties with normal arthrokinematic mobilization in joint capsules , which limit 
 joint movement when patients attempted to move joints suffering from the symptoms of joint 
 dysfunction . joint mobilization can be performed to achieve a neurophysiological effect to 
 reduce muscle pain and guarding , and a mechanical effect such as stretch or burst of 
 contracted tissues . one study reported increased active exercise by patients as a result of 
 joint mobilization3 . the physiological effects of joint mobilization , which is aimed at increasing the range of 
 joint motion and pain reduction , can be explained by the gate control theory proposed by 
 melzack and wall4 . the vicious cycle of 
 muscle pain and spasm can be broken by closing the gate where the pain stimulus is largely 
 transmitted through thin filaments , which have slow stimulus conduction velocity , while 
 proprioceptive neurons of thick filaments are stimulated . the present study aimed to determine the effect of an 8-week program of joint mobilization 
 on changes in pelvic obliquity and pain level in seventeen female university students aged 
 in their 20 s with sacroiliac joint dysfunction by dividing them into two groups : a joint 
 mobilization group , and a control group . seventeen subjects were selected from female university students aged in their 20 s 
 attending n university in cheon - an city , korea . the subjects had sacroiliac joint syndrome , 
 but experienced no problems with daily living and had no previous experience of joint 
 mobilization exercise . the subjects were randomly assigned to a joint mobilization group of 
 eight , and a control group of nine who performed joint mobilization exercise . the mobilization with movement ( mwm ) group was 21.131.46 years old , 158.596.91  cm tall , 
 and 59.5912.93 kg in weight . the control group was 23.202.15  years old , inbody 720 ( biospace , korea ) was used to measure the subjects body composition while 
 4d - formetric ( germany ) was used for pelvic analysis . body fat and lean body mass were measured using inbody 7.0 ( biospace , korea ) . the direct 
 segmental multi - frequency bioelectrical impedance analysis method ( dsm - bia ) was used for 
 body composition measurement . a pressure footstool ( pedoscan , diers , germany ) and a trunk measurement system ( formetric 
 4d , diers , germany ) , a 3d image processing apparatus with high resolution for the vertebrae 
 used in the studies of lippold and colleagues5 and schroder6 , 
 were used to measure 3d trunk images of vertebrae and pelvis obliquity , as well as static 
 balance ability . the posterior innominate and anterior innominate methods were used for joint mobilization 
 ( mobilization with movement ) . these two methods have been well described in the literature 
 by mulligan7 , both procedures were 
 repeated 10 times for one set , and for three sets ( figs 
 1 and 2fig . posterior innominate of mwm   anterior innominate of mwm spss pc for windows ( version 18.0 ) was used for data processing . in order to analyze the 
 inter - group effect , two - way anova with repeated measures if a main effect was 
 found , the paired t - test was conducted to test the difference between the groups , and 
 one - way anova was conducted to determine the difference of each parameter between the 
 groups . all the subjects understood the purpose of this study and provided their written informed 
 consent prior to their participation in the study in accordance with the ethical principles 
 of the declaration of helsinki . the pelvic obliquity dl - dr decreased by 3.25 from 4.88 before the intervention to 1.63 
 after the mobilization exercise in the control mwm group , but increased by 0.22 from 1.89 
 to 2.11 in the control group . the pelvic torsion l - r decreased by 0.5 from 2.50 to 2.00 in the mwm group , but 
 increased by 0.66 from 1.56 to 2.22 in the control group . the trunk length increased by 8.38  mm from 440.25  mm to 448.63  mm in the mwm group , but 
 decreased by 1.89  mm from 451.67  mm to 449.78  mm in the control group ( table 1)table 1 . change of pelvis malpositiongrouppre - testpost - testpelvic obliquity dl - dr ( )mwm4.882.481.631.92**control1.891.692.111.76pelvic l - r torsion ( )mwm2.500.762.000.53*control1.561.012.221.20**trunk length ( mm)mwm440.2517.62448.6315.62*control451.6716.82449.7815.93***p<0.05 , * * p < 0.01 : paired t - test . # # p<0.01 : independent t - test . * p<0.05 , * * p < 0.01 : paired t - test . # # p<0.01 : independent t - test the mean velocity decreased by 0.28  mm from 1.26  mm to 0.98  mm in the mwm group , but 
 increased by 0.1  mm from 1.13  mm to 1.23  mm in the control group . the sway area decreased by 0.14  cm from 0.21  cm to 
 0.07  cm in the mwm group , but increased by 0.07  cm from 
 009  cm to 0.16  cm in the control group . the mean frequency decreased by 0.42  hz from 0.97hzto 0.55  hz in the mwm group , but was 
 unchanged at 0.66  hz in the control group ( table 
 2table 2 . change of static stabilitygrouppre - testpost - testmean velocity ( cm / s)mwm1.260.270.980.12*control1.130.131.230.14sway area ( cm)mwm0.210.220.070.03control0.090.040.160.11mean frequency ( hz)mwm0.970.520.550.28*control0.660.260.660.18*p<0.05 , * * p < 0.01 : paired t - test . # # p<0.05 : independent t - test ) . * p<0.05 , * * p < 0.01 : paired t - test . # # p<0.05 : independent t - test the sacroiliac joint refers to the posterior joint of the bony pelvis between the sacrum 
 and the ilium of the pelvis . with its extremely limited mobility and small joint 
 mobilization , this joint rarely causes any pathological problem except for body imbalance 
 due to sacroiliac joint obliquity and changes in iliac , ischium , and length of the 
 ilium8 . the analysis of the pelvis 
 obliquity showed the intervention of this study provided the greatest statistically 
 significant interaction effect on left and right pelvis obliquity ( p<0.001 ) . furthermore , 
 a group performing combined joint mobilization and functional exercise showed statistically 
 significant differences between before and after the exercise whereas the control group 
 performing simple joint mobilization did not ( p<0.001 ) . in a previous study , yang9 reported the measurement results of changes 
 around the sacroiliac joint after 12 weeks of rolling massage for patients with chronic low 
 back pain . he found that ilium deviation was reduced by about 2.37  mm , sacroiliac joint 
 deviation by about 2.25  mm , and ischium deviation by about 2.5  mm , resulting in a 
 significant difference overall in the sacroiliac joint - related areas ( p<0.001 ) . however , 
 lee10 reported that changes in low back 
 pain found in experimental and control groups after manipulative therapy administered to 
 patients with sacroiliac joint dysfunction with muscle imbalance differed significantly 
 between the two groups before and after the experiment ( p<0.001 ) , whereas changes in 
 pelvis rotation between the experimental and control groups showed significant difference 
 between before and after the experiment ( p>0.05 ) , in contrast to our study s results . we 
 attribute difference in these study results to the difference between our joint mobilization 
 and lee s manipulative therapy , and to the lack of any functional exercise . for pain control , it is advantageous to discover and treat specific lesions causing the 
 pain ( trigger point , over - loaded muscle , weakened or abnormal movement types , or joint 
 dysfunction ) , not only to reduce the symptoms ( pain ) but also to induce functional 
 recovery11 . the results for the joint mobilization intervention used in this study show that two groups 
 of showed statistically significant decreases of pain compared to the control group 
 ( p<0.001 ) . in a previous study , lee12 reported 
 significant reductions of low back pain , functional disorder level , and low back instability 
 in patients with chronic low back pain after lower extremity strengthening exercise along 
 with low back stabilization exercise ( p<0.05 ) . he also claimed that a program of combined 
 exercise performing low back stabilization exercise and lower extremity strengthening 
 exercise was more effective at decreasing low back pain , functional disorder level , and low 
 back instability than a stabilization exercise alone . han13 reported that a combination of 
 functional exercises resulted in significant pain relief from 4.61 to 1.94 on a subjective 
 pain index ( vas ) , while simple exercise resulted in non - significant pain relief from 3.93 to 
 1.57 . furthermore , im14 reported that vas 
 showed a significant difference between before and after chuna therapy and spinal 
 stabilization exercises for 16 weeks . significant differences were also found between two 
 groups : a group of single treatment with chuna therapy and a group of combined treatment of 
 chuna therapy and spinal stabilization exercise .
[ purpose ] the present study aimed to determine the effect of an 8-week program of joint 
 mobilization on changes in pelvic obliquity and pain level in seventeen female university 
 students aged in their 20 s with sacroiliac joint dysfunction by dividing them into two 
 groups : a joint mobilization group ( mwm ) and a control group . 
 [ subjects ] seventeen 
 subjects were selected from female university students aged in their 20 s attending n 
 university in cheon - an city , korea , the subjects had sacroiliac joint syndrome , but 
 experienced no problems with daily living and had no previous experience of joint 
 mobilization exercise . 
 the subjects were randomly assigned to a joint mobilization group 
 of eight and a control group of nine who performed joint mobilization exercise . 
 [ methods ] 
 body fat and lean body mass were measured using inbody 7.0 ( biospace , korea ) . the direct 
 segmental multi - frequency bioelectrical impedance analysis method ( dsm - bia ) was used for 
 body composition measurement . 
 a pressure footstool ( pedoscan , diers , germany ) and a trunk 
 measurement system ( formetric 4d , diers , germany ) , a 3d image processing apparatus with 
 high resolution for vertebrae , were used to measure 3d trunk images of the vertebrae and 
 pelvis obliquity , as well as static balance ability . 
 [ result ] the mwm group showed a 
 significantly better balance than the control group . 
 in addition , the results of the 
 left / right and the front / rear balance abilities were significantly better than those of 
 the control group . [ conclusion ] this study proved that a combination of mobilization with 
 movement and functional training was effective in reducing pelvis malposition and pain , 
 and improving static stability control .