lumbar stability enables movements of the limbs by maintaining the vertebrae properly 
 during postural changes and in loaded states1 . we reviewed previous studies regarding lumbar stability , and noted 
 that they primarily investigated whether training of the deep muscles , such as the 
 transversus abdominis muscle and the multifidus muscles , using diverse exercise apparatuses 
 and methods such as mats , balls , dumbbells , and balance plates in prone or supine positions 
 could stabilize the vertebrae2 . due to the 
 development of industrial society , individuals today exhibit weakened abdominal muscle 
 strength , poor postures , and body imbalance , because of increasingly sedentary lives and 
 lack of exercise3 . in particular , previous 
 studies have reported that excessive biomechanical burdens due to sedentary lifestyles lead 
 to chronic weakening phenomena , such as abdominal muscle atrophy , declining muscle strength , 
 and vertebral joint instability , thereby causing pain in the regions around the lumbar 
 vertebrae , reducing endurance , and restricting the range of joint motion4 . these conditions may eventually even cause 
 damage to the vertebrae and physical disabilities5 . to find out how to improve reduced lumbar stability resulting from 
 modern people s living habits , this study asked participants to run in place with the 
 transversus abdominis muscle and the multifidus muscles in contracted states . exercises similar to running in place include plyometric training , circuit training , and 
 core stabilization . plyometric training is a method widely used to improve power , explosive 
 motions are performed while working muscles are swiftly switched from extension to 
 flexion6 . circuit training involves 
 arranging many exercises or motions selected in advance in order to continuously train many 
 muscle groups in turn , following the circuit order , without rest between each exercise7 . core stabilization exercises can maximize 
 coordination between and within segments to promote the crossing of the lumbar vertebrae and 
 the sacral vertebrae in the human body . these exercises induce continuous segmental 
 movements using mats , slings , swiss balls , etc . to develop an integrated system 
 ranging from the tip of the toes to the trunk , eventually resulting in muscle strength 
 increases8 . these exercises commonly 
 train the core muscles used to maintain the stability of the vertebrae , improving the muscle 
 strength and flexibility of the trunk9 . 
 however , plyometric training , circuit training , and core stabilization exercises require 
 systematic programs implemented under expert guidance . moreover , they require appropriate 
 equipment and a proper location . because of these drawbacks , these exercises are not 
 suitable for use by students or office workers trying to improve their trunk stability . on 
 the other hand , running in place can be done easily , regardless of time or place , and is 
 expected to stabilize the trunk by improving the stability and strength of the core region , 
 and thus the abdominal muscles . therefore , in this research , the subjects performed a 
 running in place exercise , which can be performed easily without requiring tools or 
 apparatus or being restricted by location , for six weeks . this was done with a view to 
 improving lumbar stability and examining the changes in the subjects static lumbar 
 stability ( sls ) and dynamic lumbar stability ( dls ) . thirty healthy men and women were selected and randomly assigned to a training group of 15 
 subjects ( 1 male , 14 female ) who performed the running in place exercise , and a control 
 group of 15 subjects ( 1 male , 14 female ) who did not carry out this exercise . those who had 
 any problems in their muscles , skeleton , or nervous system ; those who felt pain in their 
 lumbar region or pelvis ; and those who could not run in place due to pain in their knees or 
 ankles were excluded from this study . all the subjects understood the purpose of this study 
 and provided their written informed consent prior to their participation in this study in 
 accordance with the ethical principles of the declaration of helsinki . the training group had a mean age of 21.50.3  years , a mean height of 161.56.0  cm , and a 
 mean weight of 51.76.2  kg ; the control group had a mean age of 22.21.3  years , a mean 
 height of 162.05.5  cm , and a mean weight of 53.25.2  kg . the  test was used to 
 analyze the groups with regard to sex , and the independent t - test was used to analyze the 
 groups with regard to age , height , and weight . these analyses showed no statistically 
 significant differences ( p>0.05 ) , indicating that the two groups were homogenous . to help the subjects maintain proper positions while running in place , a 30-cm square was 
 drawn on the floor and each subject was instructed to stand in the center of the square . each subject was instructed to straighten his / her back , look straight ahead , pull in the 
 chin to maintain the position of the cervical vertebrae , and contract the transversus 
 abdominis and multifidus muscles through abdominal drawing - in to maintain the neutral 
 position of the lumbar region and the pelvis . each subject then placed their foot 
 approximately 10  cm apart , bent one knee to 90 to raise it to the height of the hip joint , 
 and bent the elbow of the arm on the other side of the raised leg to raise the arm so that 
 the hand was at the height of the eyes . each subject ran while crossing the arms and legs in 
 the sagittal plane , and repeated the running a predefined number of times . during the 
 exercise , each subject was instructed to pay attention to running in place within the limits 
 of the square while maintaining his / her posture without swinging forward , backward , 
 leftward , or rightward . to set the appropriate exercise intensities for the subjects and apply gradually increasing 
 loads , two sets were completed during the first and second weeks , and three sets were 
 completed thereafter until the end of the sixth week . each set was composed of 20 running in 
 place motions followed by a rest for 15 sec , 20 running in place motions , a rest for 15 sec , 
 30 running in place motions , a rest for 20 sec , 30 running in place motions , a rest for 20 
 sec , and 30 running in place motions . a rest of three minutes was taken after each set , and 
 one running in place motion was defined as touching the ground once with each foot . the 
 speed of running in place was designated as 17 motions per 10 seconds . light stretching for 
 five minutes was performed as a warm up before the beginning of the main exercise , and as a 
 cool down after the main exercise . the members of the control group 
 did not perform any particular exercise and followed their normal daily lives . like the 
 training group , their measurements were taken twice . to evaluate sls , the contractile force of the transversus abdominis ( tra ) was evaluated 
 using a pressure biofeedback unit ( pbu , chattanooga group , australia ) . the pbu consists of a 
 non - elastic inflatable bag connected to a pressure gauge . it is a simple piece of equipment 
 which is used to record and monitor pressure changes during the movements of the 
 lumbar / pelvic regions . the bag is 16.724.0  cm and can be used to measure pressure within 
 the range of 0200 mmhg . excessive pressure changes during evaluation indicate that the 
 movements of the lumbar / pelvic regions are not being controlled . to measure sls , each 
 subject adopted a prone position on a hard floor and the pbu was placed at the point below 
 the subject s navel where the anterior superior iliac spines cross each other . the subjects pulled in their lower 
 abdomens maximally without moving the lumbar region of the hip to reduce the pressure and 
 maintained the same pressure for 10 sec ; the change in pressure was recorded . to measure 
 dls , subjects performed the bent knee fall out ( bkfo ) , as explained by comerford and 
 mottram10 . for this measurement , the 
 pbu was placed vertically below the lumbar vertebrae , 2  cm below the posterior superior 
 iliac spine in a supine position , and folded towels of the same height as the pbu were 
 placed on both sides of the pbu in order to minimize trunk sway during movement . the subject performed abduction of 
 approximately 45 in a posture in which the hip and knee of one leg were bent and the foot 
 was placed in contact with the floor , and then returned to the initial posture ; the changes 
 in pressure during the movement were recorded . the measured data were analyzed using the spss 12.0 ko ( spss , chicago , il , usa ) statistical 
 program , and the collected data are presented as means and standard deviations . the 
 significance of the differences between before and after the experiment in each group was 
 tested using the paired t - test and the significance of the differences between the two 
 groups was tested using the independent t - test . the pre- and post - intervention measurement results of the training and control groups were 
 compared . according to the results , the training group showed statistically significant 
 differences in dls ( p<0.05 ) , while the control group showed no statistically significant 
 differences in sls or dls ( p>0.05 ) ( table 
 1table 1 . comparison of sls and dls between pre - intervention and post - intervention in each 
 group ( meansd ) ( unit : mmhg)categorygrouppre - interventionpost - interventionslstraining group1.01.92.12.7control group0.92.01.02.1dlstraining group * 3.31.41.90.8control group3.21.83.02.0 * p<0.05 , sls ; static lumbar stability , dls ; dynamic lumbar stability ) . * p<0.05 , sls ; static lumbar stability , dls ; dynamic lumbar stability the pre- and post - intervention measurement results , as well as the changes between them for 
 the training group and the control group , were compared with each other . according to the 
 results , the groups showed statistically significant differences in the post - intervention 
 measurements of dls and in the changes in dls between the pre- and post - intervention values 
 ( p<0.05 ) ( table 2table 2 . comparison of sls and dls between the training and control groups 
 ( meansd)categorytraining groupcontrol grouppre - interventionsls1.01.90.92.0dls3.31.43.21.8post - interventionsls2.12.71.02.1dls*1.90.83.02.0change between pre - and post - interventionsls1.02.30.11.2dls*1.41.40.21.1 * p<0.05 ) . in this study , the effects of running in place while using the abdominal drawing - in method 
 on healthy adults lumbar stability were examined . running in place can reduce muscle 
 fatigue and provide loads to diverse muscles to improve the respiratory and circulatory 
 systems , thereby simultaneously improving aerobic exercise ability and muscle strength . this 
 exercise is expected to train the core muscles , which are muscle groups in the trunk and 
 abdomen that maintain the stability of the vertebrae . previous studies have reported that 
 the abdominal drawing - in method is effective at increasing the activity of the abdominal 
 muscles , particularly the transversus abdominis11 . exercises similar to running in place include plyometric training , circuit training , and 
 core stabilization in which slings , swiss balls , mats , etc . myer12 instructed female high school student athletes to perform 
 plyometric training and core stabilization exercises three times per week for seven weeks to 
 prove that these exercises were effective at improving muscle strength and neuromuscular 
 control . moreover , brill9 suggested that 
 core stabilization exercises could strengthen the lumbar muscles and improve stability by 
 maintaining the balance of the vertebrae based on the contraction of the transversus 
 abdominis . endleman13 asked 18 healthy 
 adult females and 8 healthy adult males to perform pilates for six months , to exercise the 
 core region intensively , and measured the thicknesses of the transversus abdominis and 
 obliquus internus abdominis . according to the results , the tra showed significant 
 differences , proving that training the core region affected abdominal muscle strengthening 
 and abdominal stabilization positively . in this study , the pre- and post - intervention 
 measurement results of the training and control groups were compared . according to the 
 results , the training group showed statistically significant differences in dls , while the 
 control group did not show any statistically significant differences in either sls or dls . these results indicate that the running in place exercise did not affect static lumbar 
 stability , but did improve dynamic lumbar stability . these results are similar to those of 
 previous studies indicating that plyometric training , core stabilization exercises , and 
 pilates improve trunk muscle strength and lumbar stability . our results suggest that running 
 in place improves dynamic stability , particularly lumbar stability , because the running 
 exercise was performed without swaying in a defined square space while maintaining the 
 contraction of the transversus abdominis by the abdominal drawing - in method . although there 
 are diverse exercise methods to improve lumbar stability , the exercise methods used in 
 previous studies involved systematic programs carried out under expert guidance and required 
 appropriate equipment and locations for their performance . in contrast , running in place can 
 be easily carried out regardless of time or space . thus , we recommend it is utilized as an 
 exercise method for improving the dynamic lumbar stability of students or office 
 workers .
[ purpose ] the purpose of this study was to examine the effects of running in place while 
 using the abdominal drawing - in method on healthy adults lumbar stability . 
 [ subjects ] a 
 total of 30 subjects were divided into a training group of 15 subjects and a control group 
 of 15 subjects . 
 [ methods ] the training group ran in place using the abdominal drawing - in 
 method for 30 minutes per session , three sessions per week , for a total of six weeks . for 
 both the training group and the control group , static lumbar stability ( sls ) and dynamic 
 lumbar stability ( dls ) were measured before and after the experiment using a pressure 
 biofeedback unit . [ results ] pre- and post - intervention measurements 
 were compared within 
 the training group and the control group . according to the results , the training group 
 showed statistically significant differences in dls . 
 [ conclusion ] running in place , which 
 can be performed easily regardless of time and location , can be recommended as an exercise 
 that will improve the dynamic lumbar stability of students or office workers .