childhood diseases often affect development ; among these diseases , chronic nonprogressive 
 infantile encephalopathy  better known as cerebral palsy ( cp)is the most common , and 
 generally results in disabilities due to abnormal motor control1 . its clinical manifestations depend on the extent , type , and site of 
 lesions in the central nervous system ( cns ) as well as the cns s ability to adapt or 
 reorganize in response to changes2 , 3 . structural and mechanical changes in body alignment as well as musculoskeletal changes can 
 occur in cp . often , children with cp develop compensatory mechanisms to overcome gravity and 
 recruit new muscle groups to maintain stability . however , long - term compensations lead to 
 muscle imbalance , increased hypertonia , and deformities that affect postural balance , which 
 is essential for development of complex motor skills and impacts functional activities , thus 
 limiting participation in different activities . development of automatic 
 postural reactions , including straightening , balance , and protection , may also be delayed or 
 undeveloped5 . the visual , vestibular , and somatosensory systems behave as a multisensory network that 
 helps to maintain posture and balance , and it may be affected in patients with cp . these 
 systems , in combination with the cerebellar and musculoskeletal systems , are controlled by 
 the cns and are affected by experiences and environment6,7,8 . therefore , therapies such as hippotherapy may minimize the clinical 
 aspects of the disease and improve postural balance . previous studies have shown that 
 hippotherapy can improve balance and daily functional activities in patients with cp9,10,11,12,13 . different methods , including functional 
 tests and scales , have been used to assess the effects of hippotherapy on postural balance 
 in patients with cp . studies using stabilometry assessed by force platforms are less 
 common13,14,15 , and most involve the use 
 of a static position and hippotherapy simulator . the use of this technique in combination 
 with functional tests could permit a broader analysis of the effects of hippotherapy on 
 postural balance . postural balance assessment using a force platform in patients with cp in the sitting 
 position16 , 17 , is less commonly performed than that in the standing position5 , 18,19,20 . the sitting position , however , is used more often by individuals with cp during daily 
 activities because it uses less energy , provides better performance , or because individuals 
 can not maintain a standing position . in addition , this position is similar to that used in 
 hippotherapy because the child remains seated on the horse during the session and 
 experiences movements produced by the horse s gait . moreover , there is still no consensus in the literature regarding the number of 
 hippotherapy sessions necessary to change the postural balance in individuals with cp . the most common treatments included 1012 sessions10 , 11 , 15 , 23 , 34 . studies on the relationship between the 
 number of hippotherapy treatments and the effects on postural balance have not been 
 performed . the present study investigated whether hippotherapy affected seated postural balance , 
 dynamic balance , and functional performance in children with cp . in addition , the effects of 
 12 versus 24 sessions of hippotherapy on seated postural balance were compared . the 
 hypothesis was that hippotherapy would positively change seated postural balance , dynamic 
 balance , and functional performance , and that 24 sessions of hippotherapy would result in 
 better improvement in seated postural balance compared to 12 sessions . fifteen children with cp participated in the study ; they were non - probabilistically 
 recruited from hippotherapy center waiting lists ; physical therapy clinics ; and medical , 
 physical , and occupational therapist referrals . the participants and their legal guardians two cp classification systems 
 were used to characterize the participants : topographic ( hemiparesis , diparesis , or 
 quadriparesis ) and the gross motor function classification system ( gmfcs ) . all participants underwent medical and physical therapy and psychological examination 
 required for hippotherapy , according to the national hippotherapy association . to be 
 included in the study , the participants were required to meet the following criteria : cp 
 diagnosis , age between 5 and 10  years , understanding of simple commands , ability to remain 
 seated with no help for at least 10 seconds , and hip abduction of at least 20 degrees . participants with uncorrected visual and/or auditory impairment , those who underwent surgery 
 in the last 12 months and/or received chemical neuromuscular blocking for less than 6 
 months , those who had participated in any hippotherapy intervention , and individuals with 
 any clinical condition that could impede horseback riding were excluded from the study . the ethics committee of the health sciences school , university of braslia , approved the 
 assessment methods and intervention protocol under registration number 087/13 . participation 
 in this study was voluntary , and the legal guardians signed a consent form . postural balance in a sitting position was recorded 1 week before beginning hippotherapy 
 ( a1 ) , after 12 sessions ( a2 ) , and after 24 sessions ( a3 ) . the berg balance scale ( bbs ) and 
 the pediatric evaluation of disability inventory ( pedi ) were applied at a1 and a3 . before 
 the assessments , the participants were familiarized with the test environment and tools . data acquisition regarding postural balance was conducted in the laboratory , in a 
 quasi - static sitting position , using an amti accusway plus force platform ( advanced 
 mechanical technologies , inc . ) . the center of pressure ( cop ) variables analyzed included the 
 anteroposterior displacement ( copap ) , medio - lateral ( copml ) , and velocity of displacement 
 ( velcop ) . the time of acquisition for each attempt was 10 seconds at a sampling frequency of 
 100  hz , with 1-minute intervals between attempts . five attempts were made , and the three 
 best attempts from each participant were included in the analysis based on the cop variables 
 with the lowest displacement values . the platform was placed on a table 1table 1.participant descriptive characteristicsgenderagebody mass ( kg)height ( m)topographygmfcslocomotionm1025.001.21qivwheelchairf1026.001.30q iiambulant with helpm720.001.25rhiambulantm926.001.27q iambulantm813.501.08lh iambulantm625.001.18rhiambulantm719.301.20q ivwheelchairf623.001.15rhiiambulantf514.500.97qivwheelchairm917.001.20q ivwheelchairm514.501.11qivwheelchairm515.001.03rhiambulantm828.001.30qiambulantm830.001.31diambulantm1035.001.43lhiambulantm : male ; f : female ;  kg : kilogram ; m : meter ; q : quadriparesis ; rh : right hemiparesis ; 
 lh : left hemiparesis ; d : diparesis ; gmfcs : gross motor function classification 
 system meter from the wall , where a figure at each participant s eye level was 
 placed . the assessment was performed with the participant seated , centered on the platform , 
 with head and torso aligned , barefoot , and without plantar support . the arms were relaxed 
 over the thighs . m : male ; f : female ;  kg : kilogram ; m : meter ; q : quadriparesis ; rh : right hemiparesis ; 
 lh : left hemiparesis ; d : diparesis ; gmfcs : gross motor function classification 
 system after data collection , the variables were processed and calculated using balance clinic 
 software ( advanced mechanical technologies , inc . ) . dynamic balance was assessed by the bbs , which comprises 14 functional activities in 
 various common positions for daily living , such as reaching , turning , shifting , and 
 standing . to assess functional performance , pedi parts i ( children abilities ) and ii 
 ( caregiver assistance ) related to self - care , mobility , and social function were used . part 
 iii was not used because it refers to physical environment and is not quantified by a score . pedi assessment was performed by a structured interview with the children s legal 
 guardians . the hippotherapy program was performed for 30 minutes , twice a week for 12 weeks at the 
 hippotherapy center of the federal district military police , brasilia , brazil . three horses were used , all approximately 
 1.50  m tall at the withers and approximately 480  kg in body mass . a physical therapist , considered the 
 main therapist , provided treatment during each session , and a second professional stood 
 beside the horse for safety and for assisting with the proposed activities , as necessary . although an intervention protocol was used to provide a similar experience to all 
 participants , the sessions were always individual , respecting each participant s physical 
 fitness , their response to the requested activities , and their level of fatigue ; however , 
 greater independence to perform the activities was expected from the participants , and 
 intervention by the professional was offered only when necessary . the protocol started with stretching exercises for 5 minutes , with each stretch held for 20 
 seconds while the horse moved around a sand arena . the other activities were focused on 
 balance . in the sand arena , with the child seated with his or her feet in the stirrups , the 
 horses performed a zigzag trajectory with wide and tight - angled turns , and the child was 
 asked to perform 90 upper limb abduction for 4 minutes . the child s position on the horse 
 also varied , either seated on each side of the horse for 1 minute or with the back turned to 
 the horse s neck for 3 minutes . another activity included blindfolding the child for 3 
 minutes during curved and straight - line trajectories . on asphalt , with the feet out of the 
 stirrups and the hands off the handle , the frequency and the amplitude of the horse s gait 
 was alternated for 5 minutes . in addition the final 2 minutes were intended for relaxation , assuming a dorsal 
 decubitus position and saying goodbye to the horse . the statistical procedure consisted of an exploratory analysis of the data to identify 
 missing data points and outliers . in cases of moderate outliers , these data points were 
 replaced by the next highest / lowest value found for the variable , plus one . shapiro - wilk s test was used to assess data normality . after verifying data 
 normality , was verified mauchly s test was used for cop variables to assess sphericity , 
 followed by parametric repeated measures analysis of variance ( anova ) . otherwise , anova with 
 greenhouse - geisser adjustment was used . size effect and test power wilcoxon s test was used to 
 assess bbs scores and pedi variables , which had non - normal data distributions . the anthropometric characteristics of each individual , their respective cp topographic 
 classifications , and gmfcs levels are shown in table 
 1 . table 2table 2.means and standard deviations of center of pressure variables at different 
 assessment timesvariablesanm  sdcopml ( cm)a1152.07  1.32a2151.66  1.14a3151.14  0.87copap ( cm)a1142.74  1.95a2141.88  1.33a3141.09  0.48velcop ( cm / s)a1143.92  2.73a2142.83  2.04a3141.34  0.68a : assessment times ; copap : anteroposterior displacement ; copml : medio - lateral 
 displacement ; n : number of participants ; m : mean ; sd : standard deviation ; velcop : 
 velocity of displacement . difference between a1a2 , difference between a1a3 , 
 difference between a2a3 , difference between a1a2 , 
 difference between a1a3 , difference between a2a3 , 
 difference between a1a3 , difference between a2a3 includes the values of cop variables for a1 , a2 , and a3 measurements , as well 
 as the results of anova repeated measures analysis . a : assessment times ; copap : anteroposterior displacement ; copml : medio - lateral 
 displacement ; n : number of participants ; m : mean ; sd : standard deviation ; velcop : 
 velocity of displacement . difference between a1a2 , difference between a1a3 , 
 difference between a2a3 , difference between a1a2 , 
 difference between a1a3 , difference between a2a3 , 
 difference between a1a3 , difference between a2a3 multiple comparisons of the copml and copap variables showed statistically significant 
 differences between all assessment times . significant differences were observed for the 
 copml variables between a1 and a2 ( p=0.001 ) , a1 and a3 ( p=0.001 ) , and a2 and a3 ( p=0.003 ) . there were also significant differences in copap for a1 vs. a2 , p=0.006 ; a1 vs. a3 , p=0.006 ; 
 and a2 vs. a3 , p=0.029 . velcop showed significant differences between a1 and a3 ( p=0.004 ) 
 and a2 and a3 ( p=0.010 ) , but not between a1 and a2 ( p=0.175 ) . bbs scores 
 showed significant differences ( z=3.418 , p<0.001 ) between the mean values , comparing the 
 initial measure a1 ( m=27.93 ) with the final measure a3 ( m=32.53 ) , with better dynamic 
 balance observed at the end of treatment . table 3table 3.means and standard deviations of self - care and social function variables related 
 to functional skills ( fs ) and caregiver assistance ( ca)variablesanm  sdfs self - carea11555.7  14.7**a31565.4  17.3fs sociala11557.4  14.3**a31567.3  15.4ca self - carea11454.3  22.5*a31467.9  15.5ca sociala11553.0  24.9**a31565.9  18.9a : assessment times ; * p<0.05 ; * * p<0.01 presents self - care and social function scores based on pedi functional skills 
 and caregiver assistance . the mean values refer to the continuous standard scores at testing 
 for a1 and a3 . to obtain continuous standard scores , a : assessment times ; n : number of participants ; m : mean ; sd : standard deviation . * p<0.05 ; * * p<0.01 there were significant improvements in mobility scores associated with functional skills 
 ( z=3.296 , p<0.001 ) and caregiver assistance ( z=3.299 , p<0.001 ) after 24 sessions of 
 hippotherapy . the present study analyzed and compared the effects of 12 and 24 sessions of hippotherapy 
 on postural balance in a sitting position . in addition , the pre- and post - treatment effects 
 of hippotherapy on dynamic balance and functional performance in children with cp were also 
 analyzed . the results showed a decrease in copml and copap displacement and a decrease in 
 the velocity of displacement for velcop , which represents postural stability . therefore , the 
 results indicate improvement in seated postural balance after hippotherapy intervention , 
 particularly after 24 sessions . an increase in bbs and pedi scores for functional skills and 
 caregiver assistance was also observed , reflecting improvement in dynamic balance and 
 performance in daily functional activities and greater independence for the individuals 
 included in this study . these results concord with those described in a previous study11 ; both observed improvements in postural balance in the 
 sitting position after hippotherapy , including the ability to straighten the trunk after 
 displacement . the results differ from those of studies9 , 25 that used gross motor 
 function measure ( gmfm ) for assessment , which did not observe significant differences 
 related to the sitting position . hamill et al.25 also used the sitting assessment scale and did not observe 
 significant differences . finally , the study by sterba et al.9 , which assessed individuals of similar ages as those in the present 
 study over 18 sessions of hippotherapy , did not observe significant changes in the sitting 
 position . these discrepancies might be due to the different scales used and the number of 
 participants , as well we their cp classification and disease severity . the results of the assessment of static balance in the sitting position with the force 
 platform were compared with the results of studies that used hippotherapy simulators because 
 no other studies used actual hippotherapy and a force platform . although there are different 
 aspects between hippotherapy and mechanical simulator , such as contact with the animal and 
 the environment where it is conducted , studies suggest that this device offers physical 
 stimuli similar to the horse s movement patterns13,14,15 , 26 . children with cp who 
 used the simulator showed improved anteroposterior and medio - lateral displacement in the 
 sitting position compared with a control group26 . improved balance in the sitting position has also been reported in 
 children with cp , particularly among those with higher levels of disability , and these 
 improvements were maintained after treatment discontinuation15 . similar to the results of the present study , other studies reported improvement in dynamic 
 balance measured with the bbs in children with cp13 , 
 24 . with regard to functional 
 performance measured by pedi , casady et in contrast , after 24 sessions , our study observed improvement in all 
 areas , including self - care , mobility , and social function , thus allowing the children to 
 efficiently perform daily living activities related to actions such as object handling , 
 eating , hygiene , locomotion , and social interaction . hael et al.27 verified functionality improvement in two children with cp 
 assessed by pedi , suggesting that further studies should be conducted with more than the 12 
 sessions . these improvements might occur as a consequence of horse movement , which demands continuous 
 adjustments of the rider s body . when the horse moves , its center of gravity is displaced in 
 the sagittal , transverse , and frontal planes , causing continuous oscillations of the 
 individual s center of gravity due to force from the horse s back , facilitating 
 straightening - up reactions and postural balance12 , 
 13 , 24 , 
 28 . these balance reactions are induced 
 in a constant attempt to maintain balance due to the disturbances promoted by the horse s 
 rhythmic and repetitive movement10 , 23 , 29 , 30 . , sensory integration occurs between the visual , vestibular , 
 and proprioceptive systems , and specific receptors are activated to capture and encode the 
 necessary stimuli to perform the task . these stimuli are directed to corresponding areas in 
 the cortex , which through integrated and complementary information processing , provide 
 support for producing the desired response10 , 24 , 29 . the constant stimulation of these systems might increase the 
 individual s consciousness of his weight bearing , body alignment , and center of gravity29 , 31 . these stimuli provided by hippotherapy might promote neuroplasticity and lead to cns change 
 and reorganization , thus making postural adjustment more appropriate and efficient and 
 increasing the probability that learning translates to a more adequate movement pattern in 
 other environments10 , 21 , 30 . the pedi and bbs 
 results of individuals who showed greater skills in different environments for various 
 activities , such as social interaction , dressing , and locomotion , corroborate this 
 hypothesis . children with cp often show restricted trunk and hip movement , and the fixed antero or 
 retroversion pelvic position is mobilized by the horse s movement24 , 29 , 32 . the trunk and hip movements generated when riding may 
 affect balance and coordination13 , 24 , 29 , 32 . the opportunity to actively practice posture strategies and balance in changing 
 environments might promote automatic postural reactions , anticipatory response , and posture 
 control feedback . these anticipatory posture adjustments , known as feedforward , are 
 necessary for postural balance and depend on practice and experience with the task and the 
 environment33 . therefore , hippotherapy 
 might be useful in promoting this type of training because the child is continuously 
 responding to a changing environment , which stimulates these adaptive behaviors and movement 
 strategies . this need to adjust to periodic changes in the horse s body position with changes in trunk conformation demands the use of muscles and joint movements , which might lead to increased 
 strength and range of motion34 . repetition of these adjustments during hippotherapy sessions promotes strengthening of 
 pelvic , abdominal , and lumbar muscles , factors that contribute to improved trunk balance and 
 posture control23 , 26 . the activities selected for the protocol and the riding instruments may have contributed to 
 the improvements in the individuals balance and functionality . the blanket was selected 
 because it provides greater contact with the horse and allows for greater perception of the 
 animal s displacement and greater recruitment of trunk muscles32 . stretching activities while performing tasks such as 
 touching the horse s or the child s own body involve crossing the body s midline , which 
 improves positioning in children who have difficulty with this skill zigzag movements , changes in the frequency and amplitude 
 of the horse s gait , and variation in the individuals position on the horse create 
 different physical challenges and modify the proposed stimulation , thus generating 
 anticipatory and straightening - up reactions , enhancing the vestibular system and motor 
 coordination action , and strengthening muscles . when changing position on the horse , 
 different motor units are being recruited . terrain variations such as sand , asphalt , and 
 grass most likely activate the baroreceptors and stimulate proprioception10 , 11 , 24 , 28 , 29 , 32 . the blindfolded activity performed in the present study has been 
 used to overcome limits and promote greater stimulation of the vestibular and proprioceptive 
 systems , inducing an automatic trunk reaction32 . these improvements might occur because of the non - clinical environment in which the therapy 
 is conducted10 , 24 , 28 . the location where the 
 therapy is conducted ( in nature and in contact with the animal ) awakens pleasant feelings 
 and encourages greater interaction and participation of the individual during therapy24 , 35 . therefore , children are active participants involved in a movement 
 activity that might be amusing and therapeutic , which is essential for clinical improvement 
 and positive therapeutic outcomes10 , 29 , 32 , and ensures continued interest in the treatment26 , 35 . in addition , 
 motivation and pleasure in riding are important because they directly affect therapy 
 outcomes11 , 28 . because cp is a chronic condition that often demands long - term 
 involvement in therapeutic activities , it is a challenge for physical therapists to motivate 
 children to continue treatment32 . the present study also showed that two weekly sessions lasting 30 minutes each improved 
 seated balance after 12 sessions . however , 24 sessions were more effective than 12 sessions 
 in improving balance ; there was no difference in velcop between pre - intervention and 12 
 sessions . in addition , there was a significant difference between 12 and 24 sessions for all 
 analyzed variables ( copap , copml , and velcop ) . a previous study addressed the need to study 
 the effects of varying the number of sessions and the duration of sessions11 , aspects not yet widely analyzed , but 
 discussed in the present study . the limitations of the present study include the small sample size , which did not allow for 
 the use of a control group . this difficulty in recruiting a representative number of 
 individuals is common in studies on cp . studies involving patients with cp often include few 
 individuals27 , 34 , 36 , and some of these 
 studies mention the difficulty to homogenize the sample group due to the complexity of the 
 disease37 , 38 . hippotherapy treatment improved balance in the sitting position based on measures obtained 
 in a laboratory setting using a force platform . moreover , 24 sessions produced more 
 significant effects on cop displacement variables compared to those after 12 sessions . 
 therefore , the results of the current study suggest that the sensorimotor activities and 
 active posture control achieved during hippotherapy sessions may improve postural balance , 
 dynamic balance , and functional tasks in children with cp .
[ purpose ] this study evaluated the effects of hippotherapy on seated postural balance , 
 dynamic balance , and functional performance in children with cerebral palsy and compared 
 the effects of 12 and 24 sessions on seated postural balance . [ subjects and methods ] this 
 study included 15 children with cerebral palsy aged between 5 and 10  years . 
 interventions : 
 a hippotherapy protocol was performed for 30 minutes , twice a week , for 12 weeks . 
 postural 
 balance in a sitting position was measured using an amti accusway plus force platform 1 
 week before initiating the hippotherapy program and after 12 and 24 weeks . 
 the berg 
 balance scale ( bbs ) and pediatric evaluation of disability inventory ( pedi ) were used 
 before and after 24 sessions . 
 [ results ] significant differences were observed for center 
 of pressure ( cop ) variables , including medio - lateral ( copml ) , anteroposterior displacement 
 ( copap ) , and velocity of displacement ( velcop ) , particularly after 24 sessions . 
 there were 
 also significant differences in bbs scores and pedi score increases associated with 
 functional skills ( self - care , social function , and mobility ) , caregiver assistance 
 ( self - care ) , social function , and mobility . 
 [ conclusion ] hippotherapy resulted in 
 improvement in postural balance in the sitting position , dynamic balance , and 
 functionality in children with cerebral palsy , an effect particularly significant after 24 
 hippotherapy sessions .