cerebral palsy is a clinical syndrome where permanent disorders in development of posture 
 and movement are caused by non - progressive disturbances occurring in the brain of fetus or 
 infant producing activity limitation , and is frequently accompanied by disorders in 
 sensation , cognition , communication , perception , and conduct as well as seizure , etc1 .
since the cerebral palsy has diversified 
 characteristics in muscle tone and form of movement disorder due to brain damages2 , it can be classified into spastic type 
 ( 6070% ) , dyskinetic or athetoid type ( 2030% ) , ataxic type depending on the predominant 
 abnormal movement3 .
thus , movement 
 disorders as a function of diversified types of children with cerebral palsy induce 
 secondary complications and functional activity limitations related to skeletal muscles 
 system , and also affect respiratory function4 , 5 .
whereas normal respiration requires normal functions of nervous system , respiratory 
 muscles , and costovertebral joint , the children with cerebral palsy have weak muscular 
 strength of the whole body including respiratory muscles , and fail to properly remove airway 
 secretions due to spasm so that abnormal respiratory functions such as pneumonia , 
 atelectasis , epipahryngitis , etc .
also , pulmonary functions are reduced as 
 abnormal respiration methods such as shallow breathing , reverse breathing pattern of 
 children with cerebral palsy over a long period shorten respiratory muscles , and induce 
 stiffness in costovertebral joint to limit thoracic cage mobility8 . therefore , although the children with cerebral palsy do not 
 have practical problems with lung , weakening of respiratory muscles due to neurological 
 damages causes reduction in thoracic cage compliance , ventilator failure , degradation in 
 airway clearance capacity leading to a decrease in lung volume , resulting in long - term 
 hospitalization or mortality increase due to respiratory diseases7 , 9 , 10 . according to the recent studies , the children with 
 cerebral palsy are exposed to not only pulmonary function disorders but practically risks of 
 pulmonary diseases6 , 11 , and many previous studies stated that the correlation between 
 motor function disorders and respiratory functions was high12,13,14 . since respiratory muscles are essential to functional body movement and contribute to air 
 inflow and discharge of the lung , ventilation function is reduced so as to obstruct lung s 
 gas exchange when such pump action is weakened15 .
therefore , to improve respiratory functions important for heart 
 and lung capacities , training for respiratory muscles is also as important as in other 
 skeletal muscles .
respiratory training improves not only the muscle strength and endurance 
 but also the sense of wellbeing in daily living16 , and may affect changes in maximal inspiratory pressure and maximal 
 expiratory pressure17 , 18 .
therefore , functions of respiratory muscles can be 
 evaluated through mechanical measurement of maximal inspiratory pressure and expiratory 
 pressure in the state of biting a mouthpiece with lips to prevent escape of air held inside 
 the mouth . according to the previous studies , measurement of maximal inspiratory pressure 
 and expiratory pressure
was said to have more value in evaluating the function of 
 respiratory muscles while measurement of pulmonary function is very important for clinical 
 usefulness19 , 20 .
therefore , the purpose of this study was to determine differences in respiratory function 
 and pressure among three groups of children with cerebral palsy as a predominant abnormal 
 movement which included spastic type , dyskinetic type , and ataxic type .
it was also 
 conducted to provide clinically more useful basic data concerning where to put the emphasis 
 in conducting respiratory training as a predominant abnormal movement in order to prevent 
 worsening of pulmonary function of the children with cerebral palsy .
the present study was conducted to compare differences in respiratory function and pressure 
 among three groups of spastic type , dyskinetic type , and ataxic type , and was approved in 
 advance by the bioethics committee of dong - eui university ( irb no .
forty - three children with cerebral palsy as the study subjects were divided by stratified 
 random sampling into three groups of spastic type , dyskinetic type , and ataxic type .
the 
 detailed selection criteria for the subjects were first , the children of 513  years of age 
 having been diagnosed as cerebral palsy by specialized doctors in the department of 
 rehabilitation medicine / neurology ( neurosurgery ) ; secondly , the children in i  iii levels 
 according to the gross motor function classification system ; thirdly , the children capable 
 of task perform per directions given by the investigator and of appropriate communication . 
 first of all , 
subject consent  for voluntary participation was received after a sufficient 
 explanation was given to the study subjects and the guardians ( legal representative ) 
 concerning study objectives and methods , risks or inconveniences . for reliability of the measurement results , respiratory function and pressure of the 
 children with cerebral palsy
were measured by the same inspector using spirometer pony fx 
 ( cosmed ltd . ,
italy ) equipment , and the subject s custodian ( legal agent ) was always made to 
 observe . after checking first that health state of the children with cerebral palsy was 
 satisfactory ,
the inspector conducted repeated education to ensure that measurement methods 
 were sufficiently recognized allowing accurate performance .
the cerebral palsy child stared 
 at the front sitting on a chair having back rest in the most convenient clothes for 
 activity , and participated in the measurement of respiratory function and pressure . for respiratory function
, the best measurement result was selected after repetition of more 
 than 3 times so as to have no coughing , no air leaks , no false start , etc .
according to the 
 guideline by american thoracic society ( ats ) ( 1991 ) .
after having the subject breathe air in 
 and out most deeply and rapidly following normal respiration for 34 times as in daily 
 living , forced vital capacity ( fvc ) , forced expiratory volume at one second ( fev1 ) , and peak 
 expiratory flow ( pef ) were measured .
respiratory pressure was measured after sufficient rest 
 was taken following the test on respiratory function . with a mouthpiece bitten
so as to 
 prevent escape of air by maximum adherence to the lips , maximum expiration and inspiration 
 was enforced after usual respiration . for the maximal inspiratory pressure ,
the subject was 
 made to continue inspiration most deeply and rapidly for more than 2 seconds until the 
 signal sound is heard at the same time as attaching the nose plugs upon maximum expiration 
 so as to be close to residual volume . for the maximal expiratory pressure ,
the subject was 
 made to continue expiration most deeply and rapidly for more than 2 seconds until the signal 
 sound is heard at the same time as attaching the nose plugs upon maximum inspiration so as 
 to be close to the total lung capacity .
the data collected in the present study was analyzed by using spss 22.0 ( ibm corp .
, usa ) 
 for windows program , with the significant level  for statistical verification set to be 
 0.05 . as the general characteristics for the study subjects , frequency and descriptive 
 statistics were calculated , and parametric method was implemented after checking for 
 normality of the measured variables through kolmogorov - smirnov analysis .
to compare 
 differences in respiratory function and pressure among three groups of spastic type , 
 dyskinetic type , and ataxic type as a predominant abnormal movement forms , one - way anova was 
 conducted , and bonferroni analysis was used for post - hoc .
general characteristics and medical history of the study subjects are shown in table 1table 1.general characteristics and medical history of the subjects ( mean  sd)variancesmean  sdspastic ( n=28)dyskinetic ( n=9)ataxic ( n=6)general characteristicsgender ( boys / girls)13/155/44/2age ( years)7.61  2.787.44  2.888.33  1.86height ( cm)114.6  15.8120.9 
16.0120.5  11.9weight ( kg)22.7  8.224.2  7.123.2  6.3medical historydelivery ( nsvd / c - sec / induced delivery)16/9/22/4/34/3/2pregnancy week ( weeks)34.0  3.937.8  3.632.0  2.8birth weight ( g)2,352.1  564.62,991.1  626.72,045.7  490.5incubator care ( weeks)7.9  13.91.7  2.77.3  5.6nsvd : normal spontaneous vaginal delivery , c - sec : cesarean section .
no significant differences in the variables of general characteristic and 
 medical history were observed among three groups ( p<0.05 ) .
the analysis results for 
 comparison of averages of respiratory function and pressure among three groups of spastic 
 type , dyskinetic type , and ataxic type as a predominant abnormal movement of the children 
 with cerebral palsy are presented in table 
 2table 2.the comparison of respiratory function and pressure in the different 
 groupsvariancesmean  sdspastic ( n=28)dyskinetic ( n=9)ataxic ( n=6)respiratory functionfvc ( l)*1.63  0.101.40  0.121.06  0.12fev1 ( l)*1.56  0.081.28  0.141.06  0.19pef ( l / sec)*2.79  0.272.39  0.482.01  0.33respiratory pressuremip ( cmh2o)*30.55  5.5237.90  3.4524.39  3.44mep ( cmh2o)40.85  9.5238.71  7.4238.73  10.40*p<0.05 .
fvc : forced vital capacity , fev1 : forced expiratory volume in one second , pef : peak 
 expiratory flow , mip : maximal inspiratory pressure , mep : maximal expiratory 
 pressure .
significant difference between spastic type and dyskinetic type , 
 significant difference between spastic type and ataxic type , 
 significant difference between dyskinetic type and ataxic type . in the respiratory function
, there were significant differences among three 
 groups in all of forced vital capacity , forced expiratory volume at one second , and peak 
 expiratory flow ( p<0.01 ) .
according to the post - hoc results , the forced vital capacity 
 and the forced expiratory volume at one second showed a significant difference between 
 spastic type and dyskinetic type , between spastic type and ataxic type , and between 
 dyskinetic type and ataxic type , respectively .
although the peak expiratory flow showed no 
 significant differences between spastic type and dyskinetic type , and between spastic type 
 and ataxic type , it showed a significant difference only between dyskinetic type and ataxic 
 type . for respiratory pressure ,
the maximal inspiratory pressure had significant differences 
 among three groups ( p<0.01 ) , although the maximal expiratory pressure had no significant 
 difference . according to the post - hoc results
, significant differences were observed between 
 spastic type and dyskinetic type , between spastic type and ataxic type , and between 
 dyskinetic type and ataxic type .
nsvd : normal spontaneous vaginal delivery , c - sec : cesarean section * p<0.05 .
fev1 : forced expiratory volume in one second , pef : peak 
 expiratory flow , mip : maximal inspiratory pressure , mep : maximal expiratory 
 pressure .
significant difference between spastic type and dyskinetic type , 
 significant difference between spastic type and ataxic type , 
 significant difference between dyskinetic type and ataxic type
although the brain damage itself is not a direct cause producing respiratory problems of 
 the cerebral palsy8 , the children with 
 cerebral palsy showed much lower values in not only general respiratory function but also 
 respiratory muscle strength which is very closely related to self - care activities and social 
 adaptiveness in daily living when compared with normal children21 . in a study of comparing respiratory function and pressure 
 for the children with cerebral palsy according to the gross motor function classification 
 system
, the children with cerebral palsy with low motor function were found to exhibit 
 relatively unsatisfactory pulmonary capacity and weakening of respiratory muscles11 .
also , even for the children with cerebral 
 palsy of spastic type , it was stated that significant differences existed in trunk 
 expansion , respiratory muscle strength , and pulmonary function depending the invasive part 
 for diplegia and hemiplegia22 , and that 
 muscle strength of respiratory muscles of the children with cerebral palsy should be 
 considered for establishment of intervention plans to improve functions in daily living , 
 since it had positive correlations with self - management in activities of daily living and 
 performance level for social function23 . 

however , since diversified clinical problems are revealed due to weakening of respiratory 
 muscles and damages to coordination exercise in the case of children with cerebral palsy , 
 there is much difficulty in evaluation of respiratory capacity so that multi - faceted studies 
 are not being realized7 .
therefore , it is 
 considered clinically as a quite necessary study to find differences in respiratory function 
 and pressure after classification of the children with cerebral palsy showing diversified 
 qualitative movement characteristics in muscle tone and motion pattern according to the 
 predominant abnormal movement into three groups of spastic type , dyskinetic type , and ataxic 
 type . in the spastic type of cerebral palsy with high muscle tone ,
immature diaphragm respiration 
 occurs upon expiration due to stiff ribs and lack of spine mobility with rib cage not 
 expanding in front / rear , left / right , up / down directions , as a result of which forced vital 
 capacity and forced expiratory volume at one second were reduced .
also , since the maximal 
 inspiratory pressure is difficult to maintain due to the delay in diaphragm contraction , the 
 children with cerebral palsy of spastic type is considered to have attempted shallow and 
 rapid breathing . as repetition of such irregular respiration periods disables inspiration 
 for a long time , abilities to maintain peak expiratory flow and maximal expiratory pressure 

the ataxic type showing fluctuation of muscle tone and involuntary movement is incapable of 
 having a fixed posture with a tendency of the control of coordination exercise being 
 difficult upon inspiration and expiration of thoracic and abdomen parts .
namely , since the 
 abdomen muscle is unconsciously activated whereas the thoracic muscle is mainly used for 
 auxiliary purpose in the ataxic type , other muscle groups are active with expiration when 
 one muscle group is engaged in inspiration action . in this way , unsynchronized movements 
 induced in abdominal muscles , diaphragm and thoracic muscles produce shallow , rapid and 
 uncoordinated respiration , while a platy upper rib cage and a small rib cage as a whole with 
 the sternum lowered and the lower rib flared in the shape of morning glory are formed .
the 
 ataxic type showed generally higher measured values for respiratory function and pressure 
 than the ataxic type although it had lower average values for forced vital capacity , forced 
 expiratory volume at one second and peak expiratory flow than the spastic type .
this 
 suggests that the spastic type has relatively better respiratory function and pressure than 
 the ataxic type since excessive co - contraction of the trunk helps stability although the 
 spastic type has insufficient selective movement due to high muscle tone whereas the ataxic 
 type has instability due to insufficient co - contraction of the trunk making respiration 
 difficult .
also , since the children of ataxic type has rapid and irregular respiration 
 occurring together with vocalization , they are characterized by speaking while inspiring or 
 momentarily producing explosive sounds .
the maximal expiratory pressure is considered to 
 have the lowest value as it is difficult to continuously produce sounds although the maximal 
 inspiratory pressure was shown to be the highest among three groups .
the ataxic type has a lower capacity to maintain the posture against gravity since the 
 muscle tone as a whole is in the lower state than the normal .
also , since very shallow 
 inspiration is observed due to the lack of co - contraction of trunk muscle , it is considered 
 that general respiration function and pressure were shown to be the lowest compared with the 
 spastic type and the dyskinetic type . in the present study , the ataxic type was observed to 
 have a higher maximal expiratory pressure than the dyskinetic type , which is considered 
 attributable to the long stretched pronunciation when the child of ataxic type speaks . in the present study , respiratory function of the children with cerebral palsy
was observed 
 to show significant differences among three groups in all of forced vital capacity , forced 
 expiratory volume at one second , and peak expiratory flow , with the ataxic type showing the 
 lower values than the spastic type as well as the dyskinetic type .
also , although all 
 measured values of maximal expiratory pressure and respiratory pressure were similar for 
 three groups , the ataxic type showed the lowest maximal inspiratory pressure compared with 
 the dyskinetic type and the spastic type as in the respiratory function .
therefore , 
 pediatric physical therapists could be provided with important clinical information in 
 understanding the differences in respiratory function and pressure for the children with 
 cerebral palsy showing predominantly abnormal movement as a diverse qualitative 
 characteristics of the muscle tone and movement patterns , and in planning intervention 
 programs for improvement of respiratory capacity .
 [ purpose ] the purpose of this study was to determine differences in respiratory function 
 and pressure among three groups of children with cerebral palsy as a predominant abnormal 
 movement which included spastic type , dyskinetic type , and ataxic type . 
 [ subjects and 
 methods ] forty - three children with cerebral palsy of 513  years of age in i  
 iii levels 
 according to the gross motor function classification system , the study subjects were 
 divided by stratified random sampling into three groups of spastic type , dyskinetic type , 
 and ataxic type . for reliability of the measurement results , respiratory function and 
 pressure of the children with cerebral palsy 
 were measured by the same inspector using 
 spirometer pony fx ( cosmed ltd . , 
 italy ) equipment , and the subject s guardians ( legal 
 representative ) was always made to observe . 
 [ results ] in the respiratory function , there 
 were significant differences among three groups in all of forced vital capacity , forced 
 expiratory volume at one second , and peak expiratory flow . for respiratory pressure , 
 the 
 maximal inspiratory pressure had significant differences among three groups , although the 
 maximal expiratory pressure had no significant difference . 
 [ conclusion ] therefore , 
 pediatric physical therapists could be provided with important clinical information in 
 understanding the differences in respiratory function and pressure for the children with 
 cerebral palsy showing predominantly abnormal movement as a diverse qualitative 
 characteristics of the muscle tone and movement patterns , and in planning intervention 
 programs for improvement of respiratory capacity . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION