in modern society , the incidence of cervical lordosis and thoracic and lumbar kyphosis is 
 increasing , because many people maintain a fixed posture for long periods and number of aged 
 people is increasing .
an increase in thoracic kyphosis causes restrictions in chest 
 expansion and respiratory muscle weakness , thereby reducing lung capacity and the thoracic 
 cavity size and deforming vertebral column alignment1,2,3 .
previous studies have investigated the use of thoracic joint mobilization and thoracic 
 flexibility exercises to improve deformations of the chest and vertebrae and thereby enhance 
 pulmonary function1 , 4 .
these interventions enhanced pulmonary function and thoracic 
 mobility and improved respiratory muscle function , chest expansion , and diaphragm movement 
 by reducing the stiffness of the inter - vertebral discs and surrounding tissues and by 
 improving vertebral extensor muscle stretch and endurance with thoracic flexibility 
 exercises1 , 4 . as reported in previous studies , chest mobilization exercises and stretching exercises 
 increase thoracic vertebral mobility , chest expansion , and lung capacity .
however , these 
 exercises required firsthand therapeutic application by therapists and can not be easily 
 performed by the subjects in a non - clinical environment5
. therefore , the present study examined self - mobilization of thoracic vertebrae in healthy 
 adults and investigated the effect of these exercises on pulmonary function and chest 
 expansion .
the subjects of this study were 19 healthy adults who understood the purpose of the study 
 and provided written consent to participate .
those diagnosed with neurological findings and 
 had undergone operations , or were receiving surgical treatment , or taking medicines on a 
 regular basis to relieve pain , were excluded from the study .
the study was approved by the 
 ethics committee of the catholic university of pusan and adhered to the tenets of the 
 declaration of helsinki ( 1975 , revised 1983 ) .
the subjects were assigned to one of two 
 groups , the thoracic region self - mobilization group ( tsmg ; 2 males and 6 females ) or the 
 control group ( cg ; 5 males and 6 females ) .
none of the subjects showed restrictive pulmonary 
 disease or obstructive pulmonary disease , as determined by a spirometer pretest .
age , 
 height , and weight were 22.50  1.06  years , 164.25  10.60  cm , and 60.12  13.35  kg , 
 respectively in the tsmg , and were 22.36  3.26  years , 165.50  7.37  cm , and 65.09  
 14.90  kg , respectively in the cg . to measure chest expansion when breathing , the subject s chest wall was measured with a 
 tapeline in an upright sitting position .
chest expansion was calculated using the difference 
 in chest wall circumference during the state of maximal expiration and maximal 
 inspiration6 , 7 .
a spirometer ( pony fx , cosmed , italy ) was used to measure pulmonary 
 function . using a maximal - effort expiratory spirogram ,
forced vital capacity ( fvc ) , forced 
 expiratory volume in one second ( fev1 , ) , fev1/fvc , peak expiratory 
 flow ( pef ) , and predicted pulmonary function ( pred fvc , pred fev1 , pred 
 fev1/fvc , pred pef ) were measured while the subjects were in an upright 
 position1 .
thoracic region self - mobilization exercise was performed by the intervention group using a 
 method modified and a self - mobilization tool from previous studies for 20 minutes , three 
 times per week for 6 weeks5 .
if a 
 participant felt pain or inconvenience , the self - mobilization tool was moved toward the 
 transverse process of the spine or the rib , and the exercise was performed again5 . before the experiment
, the participants 
 were requested to practice 23 times to become familiar with the exercise5 .
wilcoxon signed - rank test was used to compare differences between the 
 two groups ( tsmg and cg ) .
the mann - whitney u test was used to compare the two groups at the 
 significance level of (  ) = 0.05
chest expansion ( axillary , sternum , low costal region ) measurement results are summarized 
 in table 1table 1.within-group and between - group comparisons for outcome measurestsmg ( n=8)difference ( post - pre)zcg ( n=11)difference ( post - pre)zzpre - testpost - testpre - testpost - testax4.312.106.182.011.871.452.31 * 4.773.243.060.791.703.671.682.99*st3.181.095.181.362.001.531.68 * 3.632.852.901.540.722.481.132.28*lc5.062.736.121.951.061.741.553.362.372.071.381.291.492.53*2.74*within - group comparison , between - group comparison , ax : 
 axillary region , st : sternum region , lc : low costal region , unit ; cm,*p < 0.05 , all 
 results presented as mean  sd .. comparison of pulmonary function results from the two groups showed no 
 significant differences between group variations or within group variations ( p > 
 0.05 ) . within - group comparison , between - group comparison , ax : 
 axillary region , st : sternum region , lc : low costal region , unit ; cm,*p < 0.05 , all 
 results presented as mean  sd .
chest expansion , respiratory function , and thoracic vertebral pain are adversely affected 
 by reduced thoracic vertebral mobility and structural changes in the thoracic and lumbar 
 angles8 , 9 .
although many interventions have been applied in previous studies 
 to address these issues , those interventions have shortcomings because they require 
 firsthand application by therapists1 , 4 .
therefore , the present study aimed to 
 verify whether active thoracic vertebrae self - mobilization methods are sufficient5 and to investigate changes in chest 
 expansion and pulmonary function caused by thoracic region self - mobilization .
although engaging in thoracic joint mobilization and self - stretching exercise for 6 weeks 
 improved pulmonary function in a previous study1 , another study showed no improvement in pulmonary function after 
 chest region respiratory muscle stretching exercise for 4 weeks7 .
therefore , the argument that interventions applied to the 
 thoracic region are involved in pulmonary function improvement is controversial . in the 
 present study , no significant change in pulmonary function was observed .
this may be 
 attributable to the fact that the intervention was applied to healthy subjects , who were 
 relatively less affected by the intervention .
however , the intervention applied in the 
 present study resulted in larger increases in axillary region and sternum region 
 measurements , than in previous studies in which respiratory muscle stretch gymnastics were 
 applied7 .
interestingly , previous studies have reported that changes in low costal region 
 measurements were relatively larger than changes in axillary region and sternum region 
 measurements when thoracic flexibility exercise was applied .
conversely , changes in lower 
 costal region measurements were not significantly larger in the present study4 , 7
. 
 these results may be attributable to the fact that although thoracic region 
 self - mobilization directly affected ribs 110 , which are directly connected to the thoracic 
 vertebrae or to the cartilage , it could not directly affect ribs 11 and 12 .
the control 
 group showed a statistically significant decrease in low costal region measurements 
 post - test .
thus , it could be indirectly concluded that if thoracic vertebrae are not 
 mobilized , chest region muscle stiffness persists and the mobility of the muscles around the 
 chest wall declines owing to over activation of the muscle spindles , potentially leading to 
 respiratory disorders7 , 9 .
therefore , thoracic region self - mobilization is an easy 
 intervention that can be self - applied by patients with low chest mobility in order to 
 improve expansion capability of the entire chest region .
 [ purpose ] the aim of this study was to determine the effects of thoracic region 
 self - mobilization on chest expansion and pulmonary function in healthy adults . [ subjects ] 
 nineteen healthy adults were randomly allocated to either an intervention group ( n = 8) or 
 a control group ( n = 11 ) . 
 [ methods ] subjects in the intervention group performed 
 self - mobilization of the thoracic region 3 times per week for 6 weeks ( 18 sessions ) . 
 the 
 outcome measures included chest expansion when breathing , pulmonary function , and 
 predicted pulmonary function . 
 [ results ] there was a significant difference in chest 
 expansion between the intervention group and the control group . however , there was no 
 significant difference in pulmonary function between the intervention group and the 
 control group . 
 [ conclusion ] thoracic region self - mobilization may be beneficial for 
 increasing chest expansion in healthy adults . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION