the vertebral column is a set of unstable joints , which is involved in a variety of 
 movements , including extension , flexion , right - left bending , and trunk rotation1 . because of its unstable structure ,
prior research has them reported 
 that about 80% of the global population has lasting complained of back pain or had a history 
 of back pain , and about 20% of complained of chronic low back pain ( clbp ) over 6 months2 , 3 . 

since people aged ( 30 to 50 ) have a high prevalence of clbp , it is also becoming a socially 
 and economically significant problem , and it occurs mostly in women aged 40 or older4 .
lbp can be categorized into acute ( shorter 
 than 3 months ) and chronic ( 3 months or longer ) by its duration . in lbp ,
two of the most 
 frequent types of pain are spondylogenic pain , caused by the vertebral column and its 
 appendicular structures , and neurogenic pain caused by problems in muscle - controlling 
 nerves5 .
these types of pain are caused 
 by the paravertebral muscles and other types of muscles failing to provide vertebral 
 stability , weakened vertebral bodies , disks , or ligaments between vertebral bodies , or 
 imbalance between the lumbar extensor and flexor muscles6 .
when imbalance between the abdominal muscles of the trunk and 
 extensor muscles occurs , it triggers lbp and reduces the stability of the lumbar 
 segments7 . in general ,
less than 5% of all cases 
 actually require surgical therapy , and application of non - surgical therapy alone can reduce 
 pain and restore the functions of the lumbar spine8 . in the 1980s ,
the main cause of lbp was believed to be weakness of 
 the muscles supporting the vertebral column ; therefore , application of active rehabilitation 
 exercise program to improve muscular and physical strength was considered the most ideal 
 gold - standard for patients with clbp9 , 10 . however , since recent studies have 
 reported that stability of the vertebral segments plays an important role in the mechanisms 
 underlying lbp , rehabilitation exercises based on lumbar stability , or core stabilizer 
 exercises , which can minimize instability of the vertebral segments and eventually decrease 
 lbp , is actively being used to treat lbp11 , 12 . characteristically , such rehabilitation 
 exercise not only strengthens the muscles around the spine and pelvis , including the 
 abdomen , but also activates proprioception when the body makes dynamic movements .
it is also 
 considered a therapeutic element playing a crucial role in maximizing body coordination and 
 lumbar stability through inter - neuromuscular facilitation13 .
however , park and colleagues14 reported that the use of a simple lumbar stabilization exercise 
 program , focusing on strengthening the isolated local muscles of the vertebral segments , as 
 a rehabilitation exercise method for patients with clbp , would not ease lbp and restore 
 vertebral functions . therefore , a strong correlation between muscular fitness factors and 
 neuromuscular activation in reducing lbp and achieving functional restoration may be 
 suggested .
renkawitz et al.11 reported a 
 strong correlation between restoration of muscular function in global muscles and deep trunk 
 muscles and neuromuscular activation in lbp treatment .
in other words , the complementation 
 of two types of therapy may reduce pain , support mobility of the vertebral joints , and 
 restore the muscular functions of the spine . in this respect ,
cailliet15 reported that rehabilitation exercise could play an important role 
 in restoring tissues by actively extending tendons , ligaments , and joint membranes of joint 
 tissues to facilitate blood circulation as well as improve muscular strength and 
 flexibility .
many studies have conducted exercises for improving each of the muscular functions , or 
 lumbar stabilization exercise for patients with clbp16 , 17 .
however , there has been 
 little research on the application of both lumbar stabilization exercises and an active 
 muscular fitness program in a mixed type of rehabilitation exercise .
a study of the 
 inter - group differences following the application of a complex rehabilitation program for 
 both males and females would be significant for the development of a universal lbp therapy 
 and an effective rehabilitation exercise program .
this study aimed to determine the effects of a rehabilitation exercise program combining 
 muscular fitness exercise and lumbar stabilization exercise on the lumbar isometric muscular 
 strength ( ims ) of both male and female patients with clbp in their 30s , the age group 
 participating most actively in socio - economic activities .
twenty individuals , 10 males and 10 females , who visited the j oriental medical hospital in 
 seoul participated in this study .
the participants were patients with clbp who had had lbp 
 for over 3 months and were receiving general oriental therapy .
those with severe 
 cardiovascular disease , those who could not walk , or those with symptoms of spinal tumor , 
 spinal or disk infection , inflammatory disease , mental illness , or neurological disorder 
 accompanied by motor disturbance were excluded . before conducting this experiment , only 
 those who understood the purpose of this study , and indicated their active intention to 
 participate in the experiment , after they had listened to explanation on the information and 
 procedure of the experiment
this study received approval from 
 the institutional review board ( irb ) of dongshin university on april 27 , 2014 ( irb no : 
 201401-bm-006 - 02 ) .
the participants physical characteristics are shown in table 1table 1.physical characteristics of the subjectsgroup age ( years)height ( cm)weight ( kg)bmi ( kg / m)female ( n=10)34.4  2.8163.2  2.753.0  4.120.1  1.8male ( n=10)35.3  2.9176.6  3.072.8
1.equipment used for the isometric muscular strength test shows the ims measurement system used to measure the lumbar extensor strength machine 
 ( medx , ocala , fl , usa ) . to assess the lower back and extensor strength ,
the maximum 
 isometric extensor strength was measured at lumbar joint flexion angles of 0 , 12 , 24 , 36 , 
 48 , 60 , and 72. all patients received a detailed explanation of the experimental procedure 
 in advance , were checked for lbp , and were warned of possible accidents during the test or 
 exercise .
the participants thighs and lower limbs were fixed with knee , thigh , and pelvic 
 restraints , and the foot board to prevent mobilization of leg strength during the lumbar 
 extension strength measurement .
beginning from the lumbar flexion of 72 , the participants 
 were asked to extend their waist gradually upon the tester s order , with reference to pain 
 and restricted joint angles , and to maintain the maximum muscular strength for 12 seconds 
 when the maximum strength was exerted the upper resistance pad for 23 seconds , to measure 
 extension .
equipment used for the isometric muscular strength test the rehabilitation exercise program in this study was composed of warm - up , main exercise , 
 and cool - down , and was conducted in three , 60minute sessions a week .
the program had three 
 stages , conditioning , improvement , and maintenance phases , and was a revised and 
 complemented version of the complex rehabilitation exercise program developed by park and 
 colleagues14 .
table 2table 2.the exercise program performed by the patients with clbpphasecomplex rehabilitation program typerep / set ( week)considerationap ( week 14)ms leg flexion / extension dumbbell biceps curl 
 dumbbell triceps extension calf raise lat pull down710 reps/2 sets non - weight bearing open kinetic 
 chain exercise exercise in range without pain low back flexion and extension to 
 minimize frequency and intensity of control , depending on fitness level 
 continuous supervision .
ice massage after exercisest quadruped arm / leg lifts with bracing gluteal 
 squeezes pelvic tilt710 reps/2 sets:710 reps with57  s holdip ( week 58)ms medx exercise ( isotonic) crunch machine leg 
 press supine squat ( non - weight bearing) multi - hip ( adduction , abduction , 
 flexion , extension)710 reps/3 sets : medx 15 reps/1 set closed kinetic chain exercise 
 eccentric exercise for strength enhancement return to adaptation phase , if pain 
 occurred prohibit from overloading and over - repetition recommendation of 
 minimal bed rest recommendation of continued independent ambulation avoid to 
 high impact exercise such as running ice massage after exercisest hip rotation exercise with elastic band 
 superman crunch on gym - ball side bridge on floor710 reps/2 sets : 710 reps with 510  s holdmp ( week 912)ms medx isotonic exercise standing squat ( weight 
 bearing) push - up dumbbell lateral shoulder raise 1012 reps/3 sets : medx 15 reps/1 set weight - bearing exercise functional training , 
 including agility light jogging continuous exerciserecommendatiost pnf d1-d2 side bridge on gym - ball reverse curl 
 with gym - ball superman position on gym - ball prone pull ins on gym - ball710 reps/3 sets:710 reps with510  s holdclbp : chronic low back pain ; ap : adaptation phase ; ip : improvement phase ; mp : 
 maintenance phase ; ms : muscular strength ; st : stabilization ; pnf d1-d2 : proprioceptive 
 neuromuscular facilitation diagonal pattern 1-diagonal pattern 2 .
* intensity=1 rm 
 ( repetition maximum ) 5080% ( measurement of isotonic or dynamic strength ) ; 
 type = circuit training ; rest=30  s / set shows the exercise type , frequency , intensity , time , and considerations of 
 each phase .
clbp : chronic low back pain ; ap : adaptation phase ; ip : improvement phase ; mp : 
 maintenance phase ; ms : muscular strength ; st : stabilization ; pnf d1-d2 : proprioceptive 
 neuromuscular facilitation diagonal pattern 1-diagonal pattern 2 .
* intensity=1 rm 
 ( repetition maximum ) 5080% ( measurement of isotonic or dynamic strength ) ; 
 type = circuit training ; rest=30  s / set sas ver .
the paired t - test was carried out to investigate gender differences before and after 
 the intervention .
analysis of covariance ( ancova ) was performed with prior values set as 
 covariates to examine gender differences according to experimental treatment .
when 
 inter - group differences were found , a post - test was performed using the least squares method 
 ( lsm ) . the significance level (  ) for testing the hypotheses of this study was 0.05 .
the differences in ims before and after the intervention are shown in table 3table 3.changes in ims presented by gendervariablegrouppre - testpost - test%0female51.4  26.876.5  35.825.1  7.0**male87.3  18.8135.4  15.748.1  10.2**12female73.7
 33.6106.2  51.232.5  8.6**male123.4  24.5179.0  25.055.6  12.9**24female95.1  38.6123.0  56.527.9  9.2*male151.9  35.9202.1  21.650.2  14.1**36female106.7  44.5133.5  56.626.8  6.9**male173.8  32.4219.1  25.145.3  13.5**48female117.1  48.8142.6  53.525.5  7.0**male190.6  32.6235.7  22.345.1  14.0 * 60female127.0  45.6154.4  55.827.4  7.7**male194.8  41.7246.4  25.751.6  13.8**70female137.6  52.6161.6  56.824.0  10.9*male209.6  30.2257.5  35.747.9  11.3**ims : isometric muscle strength ;
% : percent difference between pre and post ; mean  
 sd ; * p<0.05 , * * p<0.01 .
there were increases in ims at every angle for both males and females , and 
 there were statistically significant differences .
ims : isometric muscle strength ; % : percent difference between pre and post ; mean  
 sd ; * p<0.05 , * * p<0.01 the gender differences following experimental procedure as a main effect were statistically 
 significant in ims at lumbar extensor strengths of 0 , 48 and 60. to detail the differences , 
 lsm values are shown in tables 4table 4.lsm values of lumbar extension ims at 0grouplsmft - valuepost - hocfemale85.3  9.47.61**2.76*female < malemale126.6  9.4lsm : least squares method ; mean  sd ; * p<0.05 , * * p<0.01 , 5table 5.lsm values of lumbar extension ims at 48grouplsmft - valuepost - hocfemale165.9  12.35.51**2.35*female < malemale212.4  12.3lsm : least squares method ; mean  sd ; * p<0.05 , * * p<0.01 and 6table 6.lsm values of lumbar extension ims at 60grouplsmft - valuepost - hocfemale177.0 
12.15.97*2.44*female < malemale223.8  12.1lsm : least squares method , mean  sd ; * p<0.05 .
lsm of ims at the angle of 0 , 48 and 60 by gender , as shown in tables 4 , 5 and 6 , and they demonstrate that ims 
 was statistically significantly higher for males than for females .
lsm : least squares method ; mean  sd ; * p<0.05 , * * p<0.01 lsm : least squares method ; mean  sd ; * p<0.05 , * * p<0.01 lsm : least squares method , mean  sd ; * p<0.05
low back pain is a typical musculoskeletal disease caused by weakening or disharmony of the 
 inner and outer muscles of the trunk and other tissues ( tendons , ligaments , joint membranes , 
 etc . )
affecting spinal and pelvic mobility , and stabilization , mainly due to problems with 
 the musculoskeletal structure .
in particular , it varies from simple types caused by abnormal 
 biomechanical problems to complex ones caused by a variety of factors , and has various 
 symptoms , thus requiring very complicated therapies18 . as a safe method of treating lbp with relatively few side effects 
 and reducing medical expenses ,
, it is believed that 
 the development of a clinically usable rehabilitation exercise program for lbp therapy , is 
 of itself significant .
this study aimed to assess the effects of a rehabilitation exercise 
 program composed of ims exercise and lumbar stabilization exercise on lumbar ims of the low 
 back of 20 males and females in their 30s , diagnosed with clbp .
muscular exercise for strengthening the trunk muscles is a very important intervention for 
 patients with lbp .
the normal functions of various types of muscles around the vertebral 
 joints can provide stable support and enable smooth dynamic movement of the body19 . in a previous study ,
a lumbar segmental 
 stabilization exercise elicited a statistically significant effect on the in strength of the 
 muscles of the gluteus group20 . in 
 another study , aquatic therapy exercise enhanced the low back muscle strength and reduced 
 lbp of elderly females21 .
this study assessed the lumbar ims at 0 , 12 , 24 , 36 , 48 , 60 , and 72 to determine the 
 muscular fitness of patients with lbp and found there was a significant improvement across 
 the entire range measured following the performance of the complex rehabilitation program . 

as for gender differences , males showed significantly greater improvement at 0 , 48 , and 60 
 than females .
this gender difference can be considered as a difference in physiological 
 reaction to resistance exercise . in other words
, there is no gender difference in muscular 
 strength before puberty ; however , in adulthood , females have lower muscular strength than 
 males due to hormonal changes , weight , body composition , muscle mass , and transversal area 
 of muscular fibers22 .
jackson , shepherd , 
 and kell23 reported that resistance 
 exercise performed for 16 weeks reinforced the lumbar muscular strength of middle - aged 
 people with clbp .
like this study , other prior studies have reported that resistance 
 exercise beginning with low intensity and with a gradually increasing intensity and number 
 of sessions is effective at improving the muscular strength and lowering the rate of 
 repeated injury among in patients with clbp24 .
it is considered that muscular function improvement and lumbar stability exercise play 
 important roles in controlling spinal segments and providing stability in the alleviation of 
 lbp11 , 12 .
any prior studies have reported that effective rehabilitation 
 exercise activates functions of the intersegmental muscles , such as the multifidus , 
 rotators , and abdominis muscles , which contribute to the functioning of the spine , improving 
 stability and balance control of the body25 .
thus , it can be emphasized that scientific verication of an 
 exercise program is crucial for lbp therapy and recurrence . as for prior research concerning 
 specific exercise programs , park and
colleagues14 indicated that an exercise program that simultaneously strengthens 
 the deep abdominal muscles and muscles of the trunk is the most ideal method for maintaining 
 spinal stability and physical balance , and the american college of sports medicine 
 ( acsm)26 recommends that it is 
 necessary to perform lumbar and abdominal muscular strength exercises more than once a week , 
 and flexibility exercise for improving the mobility range of vertebral joints for more than 
 three sessions , 10 seconds per session .
it is also recommended that priority should be given 
 to simultaneous maintenance of the lower limbs rather than simple reinforcement of muscular 
 strength , and that spinal correction exercise for improving postural balance should be 
 performed in addition to improving lumbar muscular functions . in conclusion , this study conducted a complex rehabilitation exercise for 20 patients ( 10 
 females , 10 males ) with clbp who were in their 30s in 60-minute sessions , 3 times a week for 
 12 weeks , to determine the changes elicited in lumbar ims by gender .
males showed greater improvement than 
 females at the angles of 0 , 48 , and 60. therefore , a 12-week complex rehabilitation program 
 for muscle strengthening aimed at patients with clbp appears to be effective at improving 
 lumbar muscular strength .
 [ purpose ] the purpose of this study was to assess the effects of complex rehabilitation 
 training on chronic low back pain . 
 [ subjects and methods ] complex rehabilitation training 
 for lumbar isometric muscle strength was conducted for 12 weeks for males ( n=10 ) and 
 females ( n=10 ) with chronic low back pain , who were aged in their 30s . [ results ] isometric 
 strength of lumbar extension 
 was increased post - test , and significant differences were 
 found between males and females , at medx angle of 0 , 48 , and 60 . [ conclusion ] this study 
 showed that complex rehabilitation training had a beneficial effect on the muscle strength 
 of lumbar extension in patients with chronic low back pain . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION