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Paper text:
patients with postural adjustment disorder have impaired balance and posture . in these 
 patients , abnormal delivery of sensory information
greatly influences postural sway and 
 muscle activity , causing disability in activities of daily living and interfering with 
 treatment interventions1 .
diverse rehabilitation programs are available for functional improvement and balance 
 recovery for hemiplegic patients . among these , horseback riding is a treatment that focuses 
 on three areas : physical rehabilitation , psychological treatment , and the development of 
 social skills .
the treatment uses kinesociological movement and different walking patterns 
 such as walk , trot , and riding trot , and nature - friendly characteristics .
physical therapy 
 and psychological treatment approaches are employed to correct the horseback rider 's posture 
 and to improve the function of the tendons , ligaments , the cardiopulmonary system , and blood 
 circulation2 .
however , horseback riding 
 therapy itself presents some difficulties as a treatment due to location , costs , and risks . 

one solution to these difficulties is the horseback riding simulator , which allows simulated 
 horseback riding in a fixed space , and this exercise is possible anytime . and
riding on a simulator assists a horseback riding simulator simulates the rhythmic 
 movement of a horse , the development of equilibrium , flexibility , and whole - body muscles 
 while improving the balance and postural adjustment normal and disabled people3 , 4 . 

studies of proprioceptive neuromuscular facilitation , bobath , sling , and ball exercises have 
 examined improvements in the postural balance of stroke patients , but research on the 
 effects of horseback riding simulators is lacking . the aim of the present study was , 
 therefore , to examine the potential benefits of exercise using a horseback riding simulator 
 on the postural balance of chronic stroke patients .
this experiment included 67 stroke patients hospitalized at d hospital in daejeon , korea . 

all subjects read and signed consent forms , in accordance with the ethical standards of the 
 declaration of helsinki .
the possibility of natural recovery was minimized by selecting only 
 patients whose onset of stroke was at least 6 months prior to the experiment .
no patient had 
 diabetes , heart disease , or orthopedic problems and their korea - mental mini state 
 examination score was 24 or higher .
all subjects listened to an explanation of the purpose of this study and 
 exercise method and voluntarily participated in the experiment .
they were able to maintain a standing position independently for more than 30 seconds and 
 could walk in doors continuously for more than 30  m independently . also , they had no 
 problems with walking due to orthopedic surgery or impairment , a modified ashworth scale 
 stiffness 2 or less and a lower extremity muscle strength measured as f or higher in the 
 manual muscle test .
the subjects were divided into a horseback riding simulator exercise group ( heg , n=34 , 18 
 males and 16 females ) and a mat exercise group ( meg , n=33 , 18 males and 15 females ) . the 
 subjects ' average age , height , and weight were 56.097.22  years old , 166.057.47  cm , and 
 62.917.93 kg , respectively , for the heg , and 51.558.27  years old , 169.558.40  cm , and 
 67.058.38 kg , respectively , for the meg .
stroke was the result of cerebral infarction in 15 subjects and cerebral hemorrhage in 19 
 subjects in the heg , and cerebral infarction in 16 subjects and cerebral hemorrhage in 17 
 subjects in the meg .
the onset of stroke was between 7 and 12 months prior to the experiment 
 in 19 patients , and more than 15 months prior in 15 subjects in the heg . in the meg ,
the 
 onset of stroke was between 7 and 12 months prior to the experiment in 20 patients and more 
 than 13 months prior in 13 patients . both groups received exercise treatment three times per 
 week for 8 weeks and received ordinary physical therapy 6 times per week . a physical 
 therapist with more than 10  years of clinical experience administered the exercise 
 programs .
the heg used a horseback riding simulator ( fortis , korea ) with a shape and size similar to 
 those of a real horse ( fortis , korea ) .
the simulator had 100 different exercise programs . 
 since the subjects were patients , course number 71
was selected as it did not include abrupt 
 rhythm and had a comfortable up and down and forward and backward rhythmic movement ( the 
 distance between up and down was 52 m / min , the distance between forward and backward was 39 
 m / min , the number of up and down rhythmic movements was 90 to 100 times , the number of 
 forward and backward rhythmic movements was 90 to 100 times , and the rhythm distance was 65 
 m / min ) .
course number 74 was also selected as it had a large up and down and forward and 
 backward rhythmic movement , which has a good exercise effect on the neck , shoulders , trunk , 
 abdomen , thighs , and legs ( distance between up and down was 73 m / min , distance between 
 forward and backward was 40 m / min , the number of up and down rhythmic movements was 95 to 
 105 times , the number of forward and backward rhythmic movements was 95 to 105 times , and 
 the rhythm distance was 98 m / min ) .
the exercise was administered for a total of 35 minutes , 
 three times per week .
each course was administered for 15 minutes and the subjects rested 
 for five minutes after a course .
the exercise speed was set at a medium speed ( 50% ) , which 
 was not fast when compared to the designated rhythmic speeds of the horseback riding 
 simulator .
the risk of falling was minimized by equipping the subjects with an automatic 
 stop device .
the meg performed a trunk stabilization exercise using a mat for 35 minutes ( table 1 ) .
the trunk stabilization exercises were 
 performed using the lumbar spinal stabilization exercise methods developed by norris5 and richardson and jull6 .
the exercise session lasted 35 minutes in total , and 
 warm - up and cool - down exercises were performed for five minutes at the beginning and the end 
 of the exercises , respectively .
programs 1 through 3 were repeated 10 times per set and a 
 total of three sets were completed .
static balance was measured using a kinesthetic ability trainer ( kat ) balance system ( kat 
 2000 breg inc .
, usa ) and the center of pressure sway was recorded the moving platform of the 
 kat balance system is supported at the central point on a small pivot .
the stability of the 
 plate is regulated by an air pressure cushion between the platform and the floor .
when the 
 cushion is inflated , the platform is stabilized , and when the cushion is deflated , the 
 platform becomes very unstable .
a tilt sensor installed in front of the platform records the 
 degree of tilt of the platform from the reference point at a rate of 18.2 times per second 
 on a computer . in this experiment ,
the distance between the center of the plate and the 
 subjects ' center of pressure sway was measured in each test to calculate the balance index 
 ( bi ) .
the bi is an index of a subject 's ability to maintain his or her body close to the 
 central point of the platform ; so that a low bi score indicates a better balance sense .
the 
 subjects maintained a distance of 56  cm between their heels and stood comfortably on the 
 moving platform .
eyes open balance ( eob ) and eyes closed balance ( ecb ) were measured three 
 times for 30 seconds each time and the average values were calculated .
dynamic balance prior 
 to and after the intervention was evaluated using the berg balance scale ( bbs ) .
the paired t - test was 
 used to examine within group changes after the intervention and the independent t - test was 
 employed to examine between - group changes .
eob : eyes open balance , ecb : eyes closed balance , bbs : berg balance scale , heg : horse 
 riding simulator exercise group , meg : mat exercise group , * paired t - test , : 
 independent sample t - test , : p<0.05 according to the result of this study , eob and ecb significantly decreased and bbs had 
 significantly increased after the intervention in both the heg and the meg ( p<0.05 ) . in 
 the comparison of the groups after the intervention , ecb decreased and bbs increased 
 significantly more in the heg than in the meg ( p<0.05 ) .
there was no significant 
 difference in eob between the groups ( p>0.05 ) ( table 
 2 ) .
factors that are related to stroke patients ' gait include their direction perception , 
 standing balance , and voluntary adjustment of the affected side lower extremity , as well as 
 their sense of joint position and the existence or non - existence of joint contracture7 .
lee and jeong8 reported that when 20 
 normal adult female students performed horseback riding simulator exercises , the muscle 
 strengths in their thighs and waists were greatly improved .
therefore , since horseback 
 riding simulator exercises improve the muscle strengths in the thigh and lumbar regions , as 
 well as trunk stabilization , the aim of the present study was to examine the effects of 
 horseback riding simulator exercises on the balance ability of stroke patients .
devienne and guezennec9 in a study of 20 
 normal females , noted that horseback riding exercise increased the strength of their knee 
 flexor and the quadriceps femoris muscles .
quint and toomey10 observed that horseback riding significantly increased the range of 
 forward and backward passive tilt , of a study on 13 children with cerebral palsy .
choo11 conducted a horseback riding program for 
 children with cerebral palsy for 3 months and reported positive influences on their static 
 and dynamic equilibrium .
back et al.12 noted that 40 subjects who 
 exercised on a horseback riding simulator had greater increases in the strength of the 
 biceps brachii , transverse abdominis , abdominal oblique , and adductor longus muscles than 
 when they jogged .
lee and jeong13 
 reported that horseback simulator exercise increased muscle strengths in the femoral and the 
 lumbar areas of 20 normal female students .
cho et al.14 noted that horseback riding simulator exercise was effective at 
 improving postural balance ability and proprioceptive sense in a study of 30 normal adults . 

kuczyski and sonka15 conducted 
 horseback riding simulator exercise for 25 cerebral palsy children for 12 weeks , and 
 observed a significant improvement in their left and right balance ability .
the balance ability test administered in the present study showed that balance ability 
 after the intervention had improved in both the heg and meg , which indicates that both 
 horseback riding and mat exercises are effective at improving postural balance .
however , 
 greater improvements after the exercise were observed in the heg than in the meg in ecb and 
 bbs .
this finding is consistent with the results reported by hammer et al.16 who conducted horseback riding simulator 
 exercise for 11 multiple sclerosis patients and observed improvements in their bbs . 

similarly , beinotti et al.17 conducted 
 horseback riding exercise for 20 stroke patients and observed enhancement of their gait and 
 balance abilities .
cho et al.14 reported 
 that horseback riding simulator exercises were effective at improving postural balance 
 ability and proprioceptive sense , while nashner and peter18 reported that proprioceptive sense  improving exercises elicited a 
 larger improvement in postural sway when the eyes were closed .
in the present study , ecb 
 showed significant differences between the groups after the intervention , indicating heg 's 
 proprioceptive senses improved more than meg 's proprioceptive senses ; whereas , eob did not 
 show a significant difference .
when horseback riding simulator exercise is performed by 
 chronic stroke patients , increases in the major muscles of the upper and lower extremities 
 and trunk , and improvements in proprioceptive sense ovserved , indicating that the subjects 
 are better able to maintain their balance and equilibrium .
horseback riding rehabilitation is one of many diverse treatment methods for patients with 
 neurological damage and utilizes the gait of a horse .
the horse 's rhythmic movement 
 stimulates the patients and aids them to improve posture and balance , and has a treatment 
 effects that include reduced muscle tone , improved trunk adjustment , and enhanced 
 equilibrium responses and autonomic reflexes .
however , horses are costly and horseback 
 riding is a sport that is not easily accessible to most ordinary people .
in addition , stroke 
 patients are less likely to have an opportunity to do this sport .
horseback riding lacks 
 recognition as a form of rehabilitation , facilities for horseback riding rehabilitation , and 
 professional therapists .
however , a horseback riding simulator exercise that mimics 
 movements of a horse can be used as a therapeutic substitute for functional improvement of a 
 patients ' balance ability .
the limitations of the present study are that the number of subjects was too small to allow 
 generalization of the results , and no follow - up evaluation was conducted to determine the 
 long - term effects of horseback riding simulator exercise .
in addition , muscle strength , 
 rigidity , senses and gait ability were not examined prior to and after the exercise . 

therefore , further research is needed on the effects of horseback riding exercise on muscle 
 activities of the trunk and the lower extremities of stroke patients .
[ purpose ] the aim of this study was to examine the effects of horseback riding simulator 
 exercise on postural balance of chronic stroke patients . [ subjects ] a total of 67 stroke 
 patients were assigned either to a horseback riding simulator exercise group ( heg , n=34 ) 
 or a mat exercise group ( meg , n=33 ) . [ methods ] the subjects exercised three times per week 
 for 8 weeks . 
 static balance ability was determined by eyes open balance ( eob ) and eyes 
 closed balance ( ecb ) , which was measured using a kinesthetic ability trainer balance 
 system . 
 dynamic balance was evaluated using the berg balance scale ( bbs ) . 
 [ results ] eob 
 and ecb significantly decreased and bbs had significantly increased after the intervention 
 in the heg and the meg , and ecb decreased and bbs increased significantly more in the heg 
 than in the meg . 
 [ conclusion ] horseback riding simulator exercise is more effective than 
 mat exercise for improving the ecb and bbs of stroke patients .