from a functional perspective , the swallowing process is composed of 3 phases , namely the 
 oral , pharyngeal , and esophageal phases . in general , dysphagia caused by neurological 
 disorders
the pharyngeal phase is defined as the process from 
 pharyngeal swallowing to complete passage of food boluses through the upper esophageal 
 sphincter . in cases of epiglottal folding , the closure of the vocal cord and laryngeal vestibule is 
 incomplete in the esophageal phase ; thus , aspiration or penetration , which is the passage of 
 food boluses through the pharynx , can occur .
thus , in order to prevent aspiration pneumonia and achieve safe swallowing , optimum 
 intervention strategies that consider the symptoms of dysphagia are required . especially , as unlike stroke , neurodegenerative diseases such as parkinson s disease worsen 
 dysphagia with disease progression , regular diagnosis and rehabilitation are required for 
 the rest of the patient s life . hence , for successful rehabilitation of swallowing function 
 in parkinson s disease , a transdisciplinary approach is critical , in which physicians , 
 nurses , physical therapists , speech pathologists , and nutritionists make decisions in a 
 cooperative manner1 .
compensation techniques such as postural techniques and maneuver have been generally 
 conducted as swallowing rehabilitation interventions2 .
these compensation techniques ( e.g. , postural techniques ) have been 
 verified to be significantly effective for the enhancement of swallowing function by many 
 studies3 , 4 .
recently , expiratory muscle strength training ( emst ) was reported to be effective for 
 swallowing rehabilitation in patients with parkinson s disease5 , 6 .
emst is a treatment 
 intervention for patients with functional disorders of the respiratory system that are 
 caused by weakening of respiratory muscles .
it not only enhances respiratory functions but 
 also postpones the outbreak of complications of the respiratory system5 .
the respiratory system is 
 composed of the respiratory tract , lungs , expiratory muscles , and thoracic cage , and plays a 
 role in the inhalation of oxygen from the air and exhalation carbon dioxide produced by 
 energy metabolism7 . in particular , both 
 inspiration and expiration
are performed by the movements of the diaphragm , respiratory 
 muscles , and thoracic cage .
inspiration is performed by active movement , while expiration is 
 performed by passive elastic recoil8 .
the 
 elderly generally not just emit less amount of air because of decreased lung capacity but 
 also have to inspire more often to supply adequate amount of oxygen for the body7 .
in addition , in old age , the possibility of ultimate decline in the function of closure of 
 the vocal cord is high owing to crevice in the larynx or 
distinct glottal arrowhead ,  which 
 is the bending of the vocal cords9 . as 
 structural changes such as these can have adverse effects on the swallowing function in old 
 age , strengthening of respiratory function in swallowing rehabilitation
is crucial10 . especially in patients with parkinson s disease , respiratory problems stand out because of 
 gradual rigidity of expiratory muscles11 . 
 with the progression of parkinson s disease ,
the movements of the diaphragm and abdominal 
 muscles become abnormal12 , which 
 eventually affects both expiration and inspiration13 . therefore , strengthening of the expiratory muscle is required for 
 optimum swallowing rehabilitation .
nevertheless , studies on the respiration in parkinson s 
 disease have mainly focused on the characteristics of respiration in the disease14 , while only a few studies have been 
 conducted on the relationship between the strengthening of expiratory muscle and swallowing 
 function .
this study investigated the effect of simultaneous application of postural techniques and 
 emst on the enhancement of the swallowing function of patients with dysphagia caused by 
 parkinson s disease .
the participants of this study were 33 patients with dysphagia caused by parkinson s 
 disease who attended the rehabilitation departments of 2 general hospitals in seoul and 
 inchon between september 2014 and february 2015 .
the criteria for subject selection were as 
 follows : first , those who had aspiration or penetration discovered in the pharyngeal phase ; 
 second , those without problems in the oral phase , such as chewing ; third , those without 
 respiratory diseases such as pneumonia or asthma ; fourth , those without cognitive problems 
 with mini - mental state examination - korean version scores of>24 ; fifth , those who can 
 communicate ; sixth , those without facial paralysis ; seventh , those without moderate or 
 severe hypertension ( systolic hypertension of 160  mm  hg and diastolic hypertension of 
 100  mm  hg ) .
this study was approved by the institutional review board and was conducted in 
 accordance with the ethical standards of the declaration of helsinki .
the subjects were 
 given sufficient explanation regarding the purpose and experimental method of this study 
 before participation and provided voluntary consent .
all the subjects were randomly assigned 
 into a emst - only ( n=18 ) and a 
postural techniques plus emst  group ( n=15 ) by using the 
 table of random numbers .
the characteristics of the participants are presented in table 1table 1.characteristics of the study participantsvariablesemst ( n=18)emst+pt ( n=15)age ( years)63.8  8.265.1  9.5gender , n ( % ) male16 ( 88.8)15 ( 100)female2 ( 11.2)0 ( 0)h - y stage , n ( % ) 315 ( 83.3)11 ( 73.3)>43 ( 16.7)4 ( 26.7)vfs35.1  13.533.5  12.8data are presented as mean  sd .
emst : expiratory muscle strength 
 training ; pt : postural techniques ; h - y stage : hoehn and yahr stage ; vfs : functional 
 dysphagia scale based on videofluoroscopic studies
emst : expiratory muscle strength 
 training ; pt : postural techniques ; h - y stage : hoehn and yahr stage ; vfs : functional 
 dysphagia scale based on videofluoroscopic studies postural techniques were conducted in the order of chin tucking , head rotation , head 
 tilting , bending head back , and lying down straight for 30 minutes per session and 5 days a 
 week for 4 weeks15 , 16 .
emst 150 ( aspire products , gainsville , usa ) was used as the emst device . by referring to 
 preceding studies6 , the procedure was 
 conducted as follows : first , in order to block air passage through the nasal cavity of the 
 subject , the nasal cavity was closed by tweezers ; second , the subject held a mouthpiece in 
 the mouth , and performed inspiration and expiration as fast and strong as possible through 
 the oral cavity ; third , after performing maximum inspiration followed by maximum expiration 
 8 times in succession , the subject rested for 30 seconds ; fourth , this procedure was 
 conducted for 20 minutes . by referring to preceding studies , the threshold value of 
 resistance of emst was set at 75% based on maximum expiratory pressure .
emst was conducted 
 20 minutes a day and 5 days a week for 4 weeks .
swallowing recovery was assessed by rehabilitation physicians who did not participate in 
 the study by using the functional dysphagia scale and based on videofluoroscopic studies 
 ( vfs)17 .
the vfs scale is used to 
 identify overall swallowing problems such as aspiration observed in videofluoroscopic 
 swallowing studies ( vfss ) and is composed of a total of 100 points .
the higher the vfs scale 
 score , the more severe the problem in swallowing function . at the time of its development , 

the vfs test had a sensitivity of 8281% and a specificity of 70.792%17 . for analysis ,
first , a preliminary homogeneity test was conducted with the independent 
 sample t test or chi - square test and , second , pre - post efficiency test was conducted with a 
 paired - sample t test .
chicago , il , usa ) was used for the analysis , with 
 a significance level of 0.05 .
the results of the independent t test and chi - square test for homogeneity of age , gender , 
 y - h stage , and mean vfs scale scores in the emst - only and combined intervention groups 
 indicated no significant difference in all the items ( table 1 ) .
the result of the paired t test showed a decrease in mean vfs scale score for both groups 
 after the treatment .
the decrease in the combined intervention group was significantly 
 greater than that in the emst - only group ( table 
 2table 2.results of the assessment using the vfs based on videofluoroscopic 
 studiestestemst ( n=18)emst+pt ( n=15)baseline35.1  13.533.5  12.8post - training * 22.5  11.316.2  8.1*p<0.05 ) .
in this study , emst significantly enhanced the swallowing function of dysphagia caused by 
 parkinson s disease . like this study ,
preceding studies verified the enhancement of 
 swallowing functions , such as reduction of aspiration and opening of the upper esophageal 
 sphincter that result from emst for patients with parkinson s disease6 .
the suprahyoid muscle protects the airway by raising the hyoid bone and plays the role of 
 supporting safe swallowing by the opening cricopharyngeus muscle .
dysphagia caused by 
 neurological problems such as parkinson s disease weakens the suprahyoid and cricopharyngeus 
 muscles .
emst was verified to enhance the pharyngeal swallowing function by strengthening 
 swallowing muscles such as the suprahyoid muscle18 . in this study ,
the combined intervention group had a significantly higher enhancement of 
 swallowing function than the emst - only group , which is deemed to be the result of the 
 synergic effect of the two treatment modalities .
postural techniques such as lowering the 
 chin are performed to complement structural and physiological defects by changing the 
 direction of food boluses going down or the area of the pharynx by adjusting posture rather 
 than strengthening the muscles themselves1 .
these postural techniques have been reported to be effective for the 
 swallowing rehabilitation of patients with dysphagia who have limited movements of the 
 tongue base or have weakened laryngeal raise2 . on the other hand , emst is a muscle training method that uses 
 resistance and is effective for vitalization of swallowing muscles and raising the 
 larynx18 . in summary , simultaneous 
 application of postural techniques and emst
is presumed to have a stronger effect on the 
 enhancement of swallowing function by complementing safe swallowing and strengthening of 
 swallowing muscles . in order to investigate the vitalization of the swallowing muscles in 
 greater detail , studies that use surface electromyography
the limitations of this study are as follows : first , as the number of subjects was small , 
 generalization of the study results is difficult .
second , as most of the subjects were male 
 patients , analysis of treatment effects according to gender is required in the future . 

studies that analyze 
 the effect of the intervention duration of emst and postural techniques are required in the 
 future .
the results of this study imply that simultaneous performance of postural techniques and 
 emst is more effective than emst alone when applied in the swallowing rehabilitation for 
 patients with dysphagia caused by parkinson s disease .
 [ purpose ] this study aimed to investigate the effect of simultaneous application of 
 postural techniques and expiratory muscle strength training on the enhancement of the 
 swallowing function of patients with dysphagia caused by parkinson s disease . 
 [ subjects 
 and methods ] the subjects of this study were 18 patients who received simultaneous 
 application of postural techniques and expiratory muscle strength training and 15 patients 
 who received expiratory muscle strength training only . 
 postural techniques were conducted 
 in the order of chin tucking , head rotation , head tilting , bending head back , and lying 
 down , while expiratory muscle strength training was conducted at a resistance level of 
 about 70% of the maximal expiratory pressure . 
 swallowing recovery was assessed by using 
 the functional dysphagia scale based on videofluoroscopic studies . 
 [ results ] the mean 
 value obtained in the videofluoroscopic studies for both groups decreased after the 
 treatment . in the postural techniques plus expiratory muscle strength training group , the 
 decrease was significantly greater than that in the expiratory muscle strength 
 training - only group . 
 [ conclusion ] the results imply that simultaneous performance of 
 postural techniques and expiratory muscle strength training is more effective than 
 expiratory muscle strength training alone when applied in the swallowing rehabilitation 
 for patients with dysphagia caused by parkinson s disease . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION