children with cerebral palsy ( cp ) have a neurodevelopmental disorder due to a 
 nonprogressive lesion of the immature brain occurring early in infancy or during the fetal 
 term1 , 2 .
motor disorders of children with cp are related to primary deficits 
 ( such as spasticity , muscle weakness , reduced coordination , and a loss of selective motor 
 control ) and secondary deficits ( such as muscle contracture and bone deformities)3 , 4 . 

these changes can affect voluntary muscle recruitment and lead to impairment of motor 
 ability . compared with children with normal development ( nd ) , children with cp have various 
 muscle recruitment patterns and magnitudes5 .
abnormal gait is a common problem in children with cp . because of motor weakness and poor 
 voluntary motor control , crouched gait or diplegic gait is an important functional biomarker 
 in children with spastic diplegic cp6 , 7 .
in addition , gait in children with cp is 
 characterized by a slower walking speed , a shorter - stride length , and more time spent in 
 double support8 . due to the abovementioned 
 problems ,
a general decrease in physical activity as well as walking capacity has been 
 observed in children with cp .
van den berg - emons et al.9 and bjornson et al.10 reported that school - age children with diplegic cp were less 
 physically active than nd children .
these characteristic features influence quality of life of 
 children with cp by reduction of daily life activities and independent mobility11 .
although it is well recognized that 
 children with cp have poor gait capacity and physical activities , the majority of the 
 scientific literature in children with cp has focused on kinetics and kinematics in 
 assessment of gait analysis .
in addition , previous studies have not included a direct 
 comparison of school - age children with cp and age - matched nd children .
gait capacity limitations in children with cp appear to be related to the ability to 
 participate in day school activities , such as playground games and moving to other areas of 
 the school12 .
increasing the knowledge 
 concerning the difference in gait capacity between children with spastic diplegic cp and 
 age - matched nd children can be helpful for persons involved in the care of these 
 children .
therefore , the purpose of this study was to determine the differences in spatiotemporal 
 gait parameters between children with spastic diplegic cp and nd children .
eight 
 children with spastic diplegic cp and eight nd children participated in this study .
children 
 with cp had a gross motor function classification ( gmfc ) system level between i and ii and 
 removed their prescribed ankle - foot orthosis during the experiment .
the following inclusion - exclusion criteria were used for selection 
 of children with cp : ( 1 ) children with cp had to have a clinical diagnosis of spastic 
 diplegic cp ; ( 2 ) children with cp had to be able to walk without use of assistive devices 
 ( i.e. , walker , cane , and ankle - foot orthosis ) ; and ( 3 ) children with cp had to have not 
 undergone orthopedic surgery within at least one year and six months after botulinum toxin 
 type a ( botox ) injections prior to the experiment .
all parents consented , and the children 
 agreed to participation in the experiment ; they provided written informed consent prior to 
 their participation in the study in accordance with the ethical standards of the declaration 
 of helsinki .
objective gait analysis was performed using the orthotrak 6.4 system ( motion analysis , 
 santa rosa , ca , usa ) , and marker trajectories were obtained using an evart 6.1 real - time 
 tracking system ( motion analysis , santa rosa , ca , usa ) with an eight - camera system ( hawk 
 system , motion analysis , santa rosa , ca , usa ) .
data from two force platforms embedded into a 
 10  m walkway were collected . for gait analysis ,
passive markers were attached with adhesive 
 tape to the following locations of both lower limbs : the anterior superior iliac spine , 
 sacrum , anterior aspect of the mid thigh , lateral femoral epicondyle of the knee and mid 
 calf , lateral malleolus , base of the heel , and dorsum of the foot between the second and 
 third metatarsals .
the spatiotemporal parameters included walking velocity , cadence , stride 
 length , and percentages of single- and double - limb support .
the gmfm-66 ( gross motor functional classification 66 ) is a standardized observational 
 measurement designed for assessment of changes in five important gross motor function 
 domains over time in children with cp .
the five gross motor function domains , which include 
 66 testing items , include lying and rolling ( four items ) ; sitting ( 15 items ) ; crawling and 
 kneeling ( 10 items ) ; standing ( 13 items ) ; and walking , running , and jumping ( 24 items ) .
the 
 scoring system ranges from 0 (  does not initiate  ) to 3 (  complete)13 .
high levels of validity , reliability , and responsiveness 
 have been demonstrated in evaluations of motor function using the gmfc in children with 
 cp14 .
an independent 
 t - test was used for determination of differences in variables in terms of the baseline data 
 ( i.e. , age , height , weight , and foot length ) and spatiotemporal parameters ( i.e. , gait 
 velocity , cadence , stride length , step width , stance phase , swing phase , and double - limb 
 phase ) between children with cp and nd children .
the baseline demographic characteristics of the subjects enrolled in the study were as 
 follows .
the mean age , height , 
 and weight of the children with cp were 8.20.75  years , 125.67.05  cm , and 30.53.35  kg , 
 respectively , and those of the nd children were 9.10.44  years , 137.12.78  cm , and 
 34.62.79  kg , respectively .
four of the children with cp were classified as gmfc level i , 
 four children were classified as gmfc level ii .
data ( meansd ) for the spatiotemporal gait 
 parameters of both the children with cp and the nd children are shown in table 1table 1.comparison of spatiotemporal gait parameters in the cp and nd groupsparameterscp children ( n=8)nd children ( n=8)walking velocity ( m / min)63.99  11.22 * 107.38  5.14cadence ( step / min)89.39  8.04 * 115.44  3.17stride length ( cm)81.25  12.42 * 111.31  3.20step width ( cm)11.80  1.72 * 7.38  0.72rt .
tdls ( % /unit)18.19  3.06 * 8.88  0.67lt . tdls ( % /unit)15.33  2.73 * 8.59  0.55 * significant difference between the cp and the nd children ( * p<0.05 ) .
cp , 
 children with cerebral palsy ; nd , normal developmental child ; sls , single - limb 
 support ; idls , initial double - limb support ; tdls , terminal double - limb support .
significant differences in terms of spatiotemporal gait parameters were 
 observed between the two groups .
the scores for walking velocity , cadence , and stride length 
 in the children with cp were lower compared with the nd children , whereas the score for step 
 width was higher in the cp children compared with the nd children .
the periods of right and 
 left single - limb stance in the children with cp group were shorter compared with the nd 
 children , whereas those for right and left double - limb stance were longer in children with 
 cp compared with the nd children . *
cp , 
 children with cerebral palsy ; nd , normal developmental child ; sls , single - limb 
 support ; idls , initial double - limb support ; tdls , terminal double - limb support
the aim of this study was to describe differences in spatiotemporal gait parameters between 
 children with spastic diplegic cp , who had gmfc system levels of i or ii , and nd children , 
 and to determine the extent of the differences .
our findings showed significantly lower 
 spatiotemporal gait parameters , including walking velocity , cadence , and stride length in 
 children with spastic diplegic cp than in nd children .
step width was larger in children 
 with cp due to poor balance and gait instability .
in addition , significant differences in 
 proportions of the stance phase ( single- and double - limb stance ) were observed in children 
 with spastic diplegic cp compared to nd children .
the duration of single - limb support in 
 children with spastic diplegic cp was shorter , and that of double - limb support was 
 longer .
our findings are consistent with those of previous studies reporting deteriorated gait 
 function and altered gait pattern in children with spastic diplegic cp8 , 15 .
the findings of 
 the current study showed that walking velocity , cadence , stride length , and step width of 
 children with cp with a gmfc of between i and ii were a level of 60% , 77% , 73% , and 160% , 
 respectively , of those of nd children .
because of motor weakness and poor voluntary motor 
 control , children with cp use a wider step width than nd children16 , suggesting that children with cp may choose a wider base 
 of support in order to stabilize the center of mass .
in addition , step width showed 
 correlation with walking velocity , cadence , and stride length .
thus , children with a wider 
 step width tend to have greater difficulty in gait performance .
the percentages of right and left double - limb support and of right and left single - limb 
 support during stance phase were 188% and 179% higher and 83% and 82% lower , respectively , 
 compared with the nd children .
this is because reduced hip adduction in the stance phase 
 increases the internal abduction moment of the support limb .
previous studies have reported 
 that children with spastic diplegic cp show weakness of the hip abductor muscles17 , 18 .
thus , the gait pattern would be unstable , and less time would be 
 spent in single - limb support .
children with spastic diplegic cp with a gmfc level of i are expected to walk independently 
 indoors and outdoors and to go up and down stairs .
children with a gmfc level of ii hold 
 onto a rail when walking on stairs and are limited with respect to walking long distances . 

thus , the differences between the school - age 7 to 12  years old children with spastic 
 diplegic cp ( gmfm levels i and ii ) and age - matched nd children included limitations in 
 walking outdoors and inside the school , walking on uneven surfaces , and walking in crowded 
 places .
our results provide objective evidence of distinct differences in spatiotemporal gait 
 parameters between children with spastic diplegic cp with a gmfc level of i or ii and nd 
 children and would be helpful to persons involved in the care of these children .
the 
 therapeutic approach to management of children with cp , who have a wide base of support and 
 decreased capacity to shift weight , should be considered for improvement of ability to 
 maintain single - limb support and for improvement of ability to shift weight in order to 
 reduce the period of double - limb support . due to the small number of children with cp in the 
 present study ,
some limitations could be raised and should be taken into account when 
 interpreting the data .
in addition , because our study was only conducted in school - age 
 children with spastic diplegic cp with a gmfc system level of between i and ii , the results 
 may not be generalized to those with more severe forms of cp .
however , our study has 
 meaningful significance in that it suggests quantitative value for spatiotemporal gait 
 parameters for school - age children with spastic diplegic cp compared with nd children . 

therefore , conduct of future studies may be needed in order to clarify this issue .
 [ purpose ] the purpose of this study was to determine the differences in spatiotemporal 
 gait parameters between children with spastic diplegic cp and children with normal 
 development ( nd ) . 
 [ subjects and methods ] sixteen children ( eight children with spastic 
 diplegic cp and eight nd children ) were recruited for participation as volunteers in this 
 study . 
 the children with cp had a gross motor function classification ( gmfc ) system level 
 of between i and ii . 
 [ results ] walking velocity , cadence , stride length , and step width of 
 children with cp with a gmfc of between i and ii were a level of 60% , 77% , 73% , and 160% , 
 respectively , of those of nd children . 
 the percentages of right and left double - limb 
 support were 188% and 179% higher , respectively , and the proportion of single limb support 
 was shorter by 83% and 82% . 
 [ conclusion ] our results provide objective evidence of 
 distinct differences in spatiotemporal gait parameters between children with spastic 
 diplegic cp with a gmfc level i or ii and nd children and would be helpful to persons 
 involved in the care of these children . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION