stabilizer muscles of the trunk in the human body refer to the deep muscles that contribute 
 to stabilization .
stabilizer muscles in the waist region include the diaphragm , pelvic floor 
 muscles , transversus abdominis , internal abdominal oblique , and multifidus1 . among these stabilizer muscles ,
trunk stabilizer muscles are activated before the body initiates 
 motion to stabilize the vertebral column3,4,5 . 

when there is back pain , pain prevents some movements of the lumbar spine and pelvis , and 
 such a phenomenon weakens the stabilizer muscles , which can lead to chronic back pain6 .
it has been confirmed that the contraction 
 of stabilizer muscles is reduced and the order of muscle recruitment is reversed in patients 
 with back pain7 .
therefore , physical 
 therapy in patients with back pain focuses on rehabilitation of the stabilizer muscles to 
 reduce pain , and improve muscle endurance and muscle strength8,9,10,11 .
these 
 exercises are based on six principles : concentration , control , centering , flowing movement , 
 precision , and breathing14 . among these 
 basic principles
, breathing applies to all ranges of motion during all exercises , and 
 breathing promotes activation of the trunk stabilizer muscles14 .
even though study of effects of pilates breathing on trunk muscle 
 activation during the trunk flex in a previous study was existed15 , there was not studied another movement of trunk ( for 
 example , extension ) or function associated movement .
it is necessary to investigate the actual effects of breathing on the trunk stabilizer 
 muscles in various trunk movements .
therefore , the purpose of the present study was to 
 investigate the effects of pilates breathing on trunk muscle activities during trunk flexion 
 and extension exercise . additionally , the relationship between pilates breathing and 
 lifting , which is associated with back pain , was evaluated .
participants 
 did not have a history of trunk surgeries , existing back pain , or prior pilates experience , 
 and they did not have any problems performing exercises .
all participants received verbal and written 
 information about the study and signed a consent form .
surface electromyography ( emg ) 
 ( telemyo dts telemetry , noraxon , az , usa ) was used to measure the trunk muscle activities . 

the sampling rate was set to 1,000  hz , band pass filter was set to 20450  hz , and notch 
 filter was set to 60  hz . activities of the trunk flexors such as the rectus abdominis and 
 trunk deep stabilizers such as the transversus abdominis , internal abdominal oblique and 
 trunk extensor such as erector spinae , multifidus were measured .
electrodes were placed on 
 the muscles of the right side of the participants body , and the locations of the electrodes 
 were shaved and cleaned with alcohol before the measurements were taken to reduce impedance . 

the electrode for the rectus abdominis was placed on upper belly of the muscle below the 
 xiphoid process , 3  cm to the right of the medial line16 .
the electrode for the erector spinae was placed on the muscle , 
 3  cm to the right of the third lumbar spinous process .
the electrode for the transversus 
 abdominis / internal abdominal oblique was placed 2  cm below and medial of the right anterior 
 superior iliac spine17 .
the electrode for 
 the multifidus was placed 2  cm to the right of the fifth lumbar spinous process18 .
emg data were collected during 3 pilates 
 based therapeutic exercises at baseline and after the breathing training .
head and chest 
 curl - ups and chest - head lifts were selected for this study , as they are representative 
 motions for trunk flexion and extension .
head and chest curl - ups in supine hook - lying 
 position with both hands behind the head and maintain the chin - in position was performed 
 flex the upper trunk in the sagital plane until scapula inferior angle .
chest - head lifts in 
 prone position with both hands behind the head and maintain the chin - in position was 
 performed extend the upper trunk in the sagital plane until xiphoid process . additionally , 
 lifting tasks , which are daily activities directly related to back pain , were also 
 performed .
lifting task was lifed 10-kg weight dumbbell placed in the middle of both knee 
 with knee exed approximately 30 in 30  cm apart stance ( indicated by oor markings ) and 
 keep straight arms and maintain neutral pelvic position that extend the only hip and trunk 
 in the sagital plane until uplight the trunk .
sufficient exercise training without breathing 
 control was provided to participants by pilates instructor before the test so that the three 
 exercises could be performed accurately .
participants were allowed 30 minutes of rest after 
 the training before proceeding to the experiment .
each exercise was performed five times , 
 and emg data were recorded middle three times . to prevent muscle fatigue , 2 minutes of rest 
 were allowed in between each exercise . using a metronome , each exercise was performed for 6 
 seconds ( 3 seconds of contraction and 3 seconds of relaxation ) .
five seconds of 
 maximum isometric contraction was performed three times . after discarding 1 second from both 
 the beginning and end ,
participants were allowed to rest for more than 5 minutes after the measurement was 
 obtained . during the pre - measurement , participants were instructed to perform the exercises 
 without restricting their breathing and by using their usual breathing methods .
after the 
 pre - measurement , participants underwent pilates breathing training , which was guided by a 
 pilates instructor .
a 60-minute pilates breathing training session was performed three times 
 per week for 2 weeks .
pilates breathing training session was consists of only breathing 
 control in the supine position .
changes in the muscle activities after the experiment ( % mvic ) were investigated by 
 performing the paired t - test .
the significance level was set to<0.05 , and the 
 kolmogorov - smirnov test was performed to test for normality .
as shown in table 1table 1.comparison of muscle activities ( mvic%)exercisemusclespre - restpost - testcurl - upra38.84  21.1746.83  18.62tra / io45.07  35.1568.34  40.64**es5.52  4.845.84  3.48mf6.34  4.778.95  4.48**chest - head liftra13.17 
19.1922.64  31.46*tra / io12.84  12.9740.36  25.20***es39.72  20.7954.49  15.59**mf45.69  14.2654.40  15.27**lifting taskra6.13  4.16.61  4.59tra / io24.21  22.7239.22  25.75***es47.69  17.2853.86  15.31mf50.17  12.6462.59
asterisks indicate a significant difference 
 between pre - post test ( * p<0.05 , * * p<0.01 , * * * p<0.001 ) .
ra : rectus abdominis , 
 tra / io : transversus abdominis / internal oblique , es : erector spinae , mf : multifidus , all muscle activities increased after pilates breathing .
statistically 
 significant improvements were observed in the stabilizer muscles transversus 
 abdominis / internal abdominal oblique and multifidus .
asterisks indicate a significant difference 
 between pre - post test ( * p<0.05 , * * p<0.01 , * * * p<0.001 ) .
ra : rectus abdominis , 
 tra / io : transversus abdominis / internal oblique , es : erector spinae , mf : multifidus
the recovery of spinal stability can be achieved 
 through breath training alone20 , 21 .
pilates exercise also emphasizes the 
 importance of appropriate breathing for stabilizing the trunk22 . besides stabilizing the trunk , stabilizer muscles such as the 
 transversus abdominis , internal abdominal oblique , and multifidus also contribute to 
 voluntary respiration .
the transversus abdominis , especially , along with the diaphragm , is 
 activated during exhalation , and it experiences the largest change in thickness during 
 maximal exhalation23 .
additionally , the 
 transversus abdominis , along with diaphragm movement , can induce isometric contraction of 
 the trunk stabilizer muscles and activation of the pelvic floor muscles by increasing 
 abdominal pressure .
therefore , incorporating abdominal respiration during trunk 
 stabilization exercises can produce better results24 , 
 25 . since activities of the trunk 
 stabilizer muscles can be regulated by one s breath , breathing
our study s results showed that performing pilates breathing 
 during curl - ups , chest - head lifts , and lifting tasks significantly increased activities of 
 the transversus abdominis / internal abdominal oblique and multifidus .
reported 
 that activities of the transversus abdominis or internal abdominal oblique significantly 
 increase when pilates breathing is incorporated , which coincides with our study s 

yoon et al . also reported 
 that slow exhalations during curl - ups selectively increase activities of the transversus 
 abdominis and internal abdominal oblique26 .
the present study differs from previous studies since an 
 intervention period was allocated for breathing training .
in addition , previous studies were 
 limited to curl - ups and trunk flexions , whereas our study measured activities of all the 
 flexion , extension , and stabilizer muscles of the trunk . the effects of pilates breathing on 
 trunk muscles during lifting tasks were also investigated .
isometric contraction of the trunk muscles can reduce the risk of back pain during lifting 
 tasks30 . increased activities of the 
 trunk muscles with pilates breathing
indicate that pilates breath training during lifting 
 tasks can reduce the risk of back injuries .
patients with acute back pain can not easily move 
 their spine due to severe pain .
trunk movements are also restricted in patients immediately 
 after surgery due to severe pain and possible side effects .
pilates breathing can induce 
 muscle activation even without actual body movements . therefore , effectiveness of pilates 
 breathing trainings in patients with acute back pain or in those whose trunk movements are 
 restricted due to a recent back surgery or surgical procedure is suggest future studies .
the 
 current study s findings show immediate results after the breath training intervention . 

therefore , a further study in which participants are followed up for a specific period is 
 necessary to determine the long - term effects of breath training .
our study s results show that pilates breathing increases activities of the transversus 
 abdominis / internal abdominal oblique and multifidus .
therefore , the use of pilates breathing 
 can more effectively increase activities of the muscles during trunk - stabilizing exercises . 
 moreover
, performing pilates breathing during lifting tasks can prevent potential injuries 
 by increasing muscle activities .
lastly , pilates breathing can be an effective method for 
 patients with acute back pain or those who have undergone back surgery and have restricted 
 trunk movement .
 [ purpose ] to investigate the effects of pilates breathing on trunk muscle activation . 
 
 [ subjects and methods ] twenty - eight healthy female adults were selected for this study . 
 
 participants trunk muscle activations were measured while they performed curl - ups , 
 chest - head lifts , and lifting tasks . 
 pilates breathing trainings were performed for 60 
 minutes per each session , 3 times per week for 2 weeks . 
 post - training muscle activations 
 were measured by the same methods used for the pre - training muscle activations . [ results ] 
 
 all trunk muscles measured in this study had increased activities after pilates breathing 
 trainings . 
 all activities of the transversus abdominis / internal abdominal oblique , and 
 multifidus significantly increased . 
 [ conclusion ] pilates breathing increased activities of 
 the trunk stabilizer muscles . 
 activation of the trunk muscle indicates that practicing 
 pilates breathing while performing lifting tasks will reduce the risk of trunk 
 injuries . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION