Effects of Therapeutic Horseback Riding on Cognition and Language in Children With Autism Spectrum Disorder or Intellectual Disability: A Preliminary Study

Abstract

Objective:
To investigate if therapeutic horseback riding (THR) can improve language and cognitive function in children with autism spectrum disorder (ASD) or intellectual disability (ID).

Methods:
We conducted a prospective case-control study on children diagnosed with ASD or ID. Eighteen and 11 children were enrolled for THR and control groups, respectively. For 8 weeks, those in the THR group underwent conventional therapy plus 30 minutes of THR per week while controls only received conventional therapy. Participants' language (using Receptive and Expressive Vocabulary Test [REVT] and Preschool Receptive-Expressive Language Scale [PRES]) and cognitive abilities (using Kaufman Assessment Battery for Children [K-ABC] and the cognitive domain of Bayley Scales of Infant Development-II [BSID-II]) were assessed at baseline and at 8 weeks after treatment.

Results:
There was no baseline difference between the two groups. In the THR group, there were statistically significant improvements in most domains after THR including receptive and expressive language and cognition compared to those before THR. In the control group, however, only receptive vocabulary ability assessed by REVT and cognitive function assessed by BSID-II showed improvements after conventional therapy. However, there were no statistically significant differences in language or cognitive abilities between the two groups at 8 weeks after treatment.

Conclusion:
These results suggest that THR might improve language and cognitive abilities. Although the mechanisms and pathways involved in such improvements are currently unclear based on our findings, THR might have potential to optimize language and cognitive abilities of children with ASD and ID.

Full text

Annals of Rehabilitation Medicine
Original Article
Ann Rehabil Med 2019;43(3):279-288
pISSN: 2234-0645 • eISSN: 2234-0653
https://doi.org/10.5535/arm.2019.43.3.279
Effects of Therapeutic Horseback Riding on
Cognition and Language in Children With
Autism Spectrum Disorder or Intellectual
Disability: A Preliminary Study
Sara Kwon, MD1, In Young Sung, MD, PhD1, Eun Jae Ko, MD, PhD2, Han Seon Kim, MD3
1Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul;
2Department of Physical Medicine and Rehabilitation, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan;
3Department of Rehabilitation Medicine, Ulsan City E Hospital, Ulsan, Korea
Objective To investigate if therapeutic horseback riding (THR) can improve language and cognitive function in
children with autism spectrum disorder (ASD) or intellectual disability (ID).
Methods We conducted a prospective case-control study on children diagnosed with ASD or ID. Eighteen
and 11 children were enrolled for THR and control groups, respectively. For 8 weeks, those in the THR group
underwent conventional therapy plus 30 minutes of THR per week while controls only received conventional
therapy. Participants’ language (using Receptive and Expressive Vocabulary Test [REVT] and Preschool Receptive-
Expressive Language Scale [PRES]) and cognitive abilities (using Kaufman Assessment Battery for Children [K-ABC]
and the cognitive domain of Bayley Scales of Infant Development-II [BSID-II]) were assessed at baseline and at 8
weeks after treatment.
Results There was no baseline difference between the two groups. In the THR group, there were statistically
significant improvements in most domains after THR including receptive and expressive language and cognition
compared to those before THR. In the control group, however, only receptive vocabulary ability assessed by REVT
and cognitive function assessed by BSID-II showed improvements after conventional therapy. However, there
were no statistically significant differences in language or cognitive abilities between the two groups at 8 weeks
after treatment.
Conclusion These results suggest that THR might improve language and cognitive abilities. Although the
mechanisms and pathways involved in such improvements are currently unclear based on our findings, THR
might have potential to optimize language and cognitive abilities of children with ASD and ID.
Keywords Therapeutic horseback riding, Autism spectrum disorder, Intellectual disability, Cognition, Language
Received August 7, 2018; Accepted December 12, 2018
Corresponding author: In Young Sung
Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505,
Korea. Tel: +82-2-3010-3800, Fax: +82-2-3010-6964, E-mail: iysung@amc.seoul.kr
ORCID: Sara Kwon (http://orcid.org/0000-0002-7088-3393); In Young Sung (http://orcid.org/0000-0001-6545-6744); Eun Jae Ko (http://orcid.
org/0000-0001-7198-5407); Han Seon Kim (http://orcid.org/0000-0001-5031-7987).
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/
licenses/by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright © 2019 by Korean Academy of Rehabilitation Medicine

Sara Kwon, et al.
280 www.e-arm.org
INTRODUCTION
Recently, there has been increasing interest in therapy
using horses as part of integrated rehabilitation treat-
ment programs for various disease entities. Such therapy
has been associated with significant positive effects.
These therapies are referred to by different terms, includ-
ing ‘therapeutic horseback riding (THR)’, ‘hippotherapy’,
and ‘psychoeducational horseback riding’ according to
therapeutic focuses of each method. The terminology en-
compassing all of these different terms is ‘equine-assisted
activities and therapy (EAAT)’. In general, hippotherapy is
led by an occupational therapist, a physiotherapist, and a
speech therapist using movement of horse to obtain tar-
geted functional outcomes. It tends to focus on posture,
balance, and mobility. THR has broader targeted thera-
peutic focuses, including physical, social, learning, sen-
sory, and psychological goals, like a relationship between
the rider and the horse [1-3].
The majority of previous studies related to EAAT have
focused on its effects on physical performance. It has
been found that EAAT can enhance physical abilities of
children with cerebral palsy or spinal cord injury [1-5]
and adult patients with stroke or multiple sclerosis [6-
8]. Although effects of EAAT on physical disabilities are
well-documented, there is less evidence of its effects on
psychobehavioral aspects. It has been reported that EAAT
is effective in children with attention deficit hyperactiv-
ity disorder (ADHD), especially several domains of social
role behavior and quality of life [9]. A study on effects of
THR on post-traumatic stress disorder (PTSD) in military
veterans has demonstrated that THR can decrease PTSD
scores and relieve clinical symptoms such as re-experi-
encing, avoidance, negative alterations in mood and hy-
perarousal [10]. Several randomized control studies con-
ducted in children with autism spectrum disorder (ASD)
have demonstrated improvements in social interactions,
behavior, and attention after THR [11,12]. Moreover, it
has been shown that equestrian rehabilitation and ono-
therapy for adults with intellectual disability (ID) can im-
prove their autonomy and social integration [13].
ASD is characterized by impaired capacity for social
communication and interaction across multiple contexts
as well as by restricted and repetitive patterns of behav-
ior and interest [14,15]. ID is characterized by significant
impairments in intellectual functioning and two or more
adaptive skill areas [16]. As neurodevelopmental disor-
ders, they have common problems such as self-control,
social interaction, attention, learning ability, and social
communication [17]. In addition to social communica-
tion impairments, approximately half of children with
ASD also have diminished intellectual capacity [18,19].
Impairments of language and cognition in children with
these disorders hinder their social interactions and activ-
ities of daily living. These impairments can also increase
long-term financial and social burdens placed on care-
givers of children with ASD and ID [20,21].
Despite growing interest in THR, only a handful of
studies have evaluated beneficial effects of this therapy
on psychosocial and behavioral aspects in children with
neurodevelopmental disorders like ADHD, ASD, and ID.
Even fewer studies have addressed its effects on language
and cognitive function. Previous research has demon-
strated that EAAT can lead to improved social interac-
tions and attention. Based on this, we hypothesized that
cognitive function and communication skills of children
with neurodevelopmental disorders could be improved
after THR. This preliminary study aimed to investigate if
THR could improve language skills and cognitive func-
tion of children with ASD and ID.
MATERIALS AND METHODS
Participants
This study was approved by Asan Medical Center Insti-
tutional Review Board (No. 2016-0338). Participants were
eligible for inclusion if the following criteria were met: (1)
diagnosis of ASD or ID, (2) age between 6 and 13 years,
(3) body weight <35 kg and height <150 cm (taking horse
size into consideration), (4) ability to understand simple
instructions, (5) appropriate physical development for
rehabilitative horseback riding (judged by medical staff),
(6) and informed consent from their legal guardian. Ex-
clusion criteria were as follows: (1) other neurological
disorders (such as epilepsy), (2) cardiovascular problems
(such as uncorrected symptomatic congenital heart de-
fects), (3) orthopedic problems that could limit physical
activities (such as fracture, or severe deformity, or con-
tracture of limb), (4) judged by the medical staff to have
problems preventing participation, (5) experience of
horseback riding at another institution, or (6) participat-
ing in other research.

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In this prospective case-control study, we screened
patients who visited the outpatient clinic of the Depart-
ment of Rehabilitation Medicine, Asan Medical Center
from November 1, 2015 to May 31, 2016 to identify eli-
gible subjects. Of these, 29 patients were diagnosed with
ASD or ID who had age of 6 to 13 years. Nineteen were
excluded according to the exclusion criteria. Additional
24 children were recruited from schools for children with
disabilities. Of them, three withdrew before the begin-
ning of the study. Thus, a total of 31 eligible participants
who met the inclusion criteria were assigned to either
the THR group or the control group. The first 19 children
enrolled were assigned to the THR group and the latter
12 were assigned to the control group. During the follow-
up period, one participant withdrew from each group.
The withdrawal from the THR group occurred due to per-
sonal reasons and the withdrawal from the control group
was because the subject’s irritability prevented baseline
evaluations from being carried out (Fig. 1).
Study design and intervention
In the THR group, 18 subjects participated in THR while
maintaining conventional therapy that they had previ-
ously been receiving. In the control group, 11 subjects
continued conventional therapy only. Thirty-minute
THR sessions were conducted once a week for 8 weeks (8
sessions). Before beginning the program, we provided a
general orientation for participants and their caregivers.
These sessions were held in a 20 m×40 m indoor riding
center of Let’s Run Park, Seoul Riding Healing Center
located in Gwacheon, Gyeonggi-do, Korea. Five people
participated in each THR sessions: a rider, a rehabilita-
tion horseback riding instructor with a national license
and more than 5 years of experience (more than half of
which were with an international license), a leader, and
two side-walkers on both sides of the horse. The leader
skillfully controlled the horse during rehabilitation rid-
ing sessions to ensure the safety of the entire course. For
the rider’s safety, side-walkers walked beside the horse
on both sides and helped the rider concentrate on the
instructor. The leader and side-walkers were trained
Screening
Among the children who visited clinic of PRM
and diagnosed with ASD or ID, we identified
children who met inclusion/exclusion criteria.
10 patients eligible for the study were included
19 patients were excluded:
4 exceeded 35 kg
3 inappropriate physical ability
3 other neurologic/orthopedic problems
2 participated in HRTat another institution
1 participated in other research
6 did not have consent from their guardian
A total of 31 patients were included
1 dropout occurred
during THR
THR group (n=18)
THR group (n=19)
8-week of THR plus
conventional therapy
21 patients eligible for the study were included
3 dropped out for
private reasons
Recruited 24 subjects who met inclusion/exclusion
criteria fromaspecial-education school
Control group (n=12)
Control group (n=11)
1 dropout occurred
after initial evaluation
8-week of
conventional therapy
Fig. 1. Flowchart illustrating the inclusion/exclusion criteria and follow-up of subjects in this study. PRM, Department
of Rehabilitation Medicine - Pediatric Division; ASD, autism spectrum disorder; ID, intellectual disability; THR, thera-
peutic horseback riding.

Sara Kwon, et al.
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volunteers. All riders were instructed to wear helmets
for safety. Horses used in THR were ponies that weighed
about 400 kg with height (measured from the forelimb to
shoulder) of about 150 cm.
Subjects who were assigned to the THR group partici-
pated in stretching exercises on the horse for 3 minutes
before and after the riding. In particular, THR sessions
encouraged participants to interact with horses allowing
them to develop a rapport through a variety of activities
such as brushing, feeding, and putting stickers on their
horses. THR progressed in several steps based on the
degree of achievement and the condition of the child.
The protocol included learning how to operate reins and
how to stop the horse, maintaining appropriate posture,
trying more than four transitions (walk-halt-walk) with
minimal assistance, and attempting to steer for 50% of
the time with minimal assistance. If children were loud
or distracted, their instructors provided feedback imme-
diately. For each session, the instructor and the leader
documented the participant’s condition, achievements,
and shortfalls. These records were shared with the par-
ticipants’ caregivers.
Outcome measures
Language and cognitive function assessments were
conducted to evaluate baseline and post-therapeutic
states of participants. We assessed the THR group and the
control group at pre- and post-intervention at intervals of
8 weeks.
Language function was evaluated using the Receptive
and Expressive Vocabulary Test (REVT) and Preschool
Receptive-Expressive Language Scale (PRES). For REVT
and PRES, children were evaluated by speech therapists
from the Department of Rehabilitation Medicine, OO
Hospital. REVT was administered to all subjects. It was
developed to assess receptive and expressive vocabu-
lary abilities of young children and adults [22]. The test
consisted of two parts: REVT-R (receptive) and REVT-
E (expressive). REVT-R consisted of 185 items, includ-
ing 98 nouns, 68 verbs, and 19 adjectives and adverbs.
REVT-E also consisted of 185 items, including 106 nouns,
58 verbs, and 21 adjectives and adverbs. REVT-R was
performed by selecting one picture corresponding to
the target word from four presented pictures. REVT-E
allows the subject to look at the presented picture and
express the corresponding word. PRES, a tool for assess-
ing overall language development and communication,
provides language developmental age of the subject be-
ing assessed. It was developed to assess receptive and
expressive language ability of children aged 2 to 6 years.
The test consisted of 45 questions each for expressive and
receptive language domains. Contents of PRES included
semantics, syntax, and pragmatics. It uses various exami-
nation methods, such as pictures, objects, instructions,
and interviews [23]. In the present study, PRES was only
applied to subjects whose speech and language abilities
were deemed to be above the threshold for valid assess-
ment by a speech therapist. Since the vocabulary and
the syntax are considered basic parts of communication
reflecting language ability [24,25], we used these two test-
ing methods to evaluate language function.
Cognitive function was assessed using the Kaufman As-
sessment Battery for Children II (K-ABC-II) or the cogni-
tive domain of the Bayley Scales of Infant Development II
(BSID-II). These were implemented by experienced pedi-
atric occupational therapists from the Department of Re-
habilitation Medicine, Asan Medical Center. K-ABC-II is a
standardized test that assesses intelligence and achieve-
ment in children aged 3 to 18 years old. Of two theoretical
models of intelligence—the Cattell-Horn-Carroll (CHC)
model and the Luria model—we used the Luria model in
this study. It consisted of four subscales: simultaneous
processing, sequential processing, planning, and learn-
ing. Scores of the test are calculated as a global score
called Mental Processing Index (MPI) based on age-
standardized scores and percentile ranks [26]. If the K-
ABC-II assessment was difficult to apply, we instead con-
ducted cognitive assessment using the cognitive domain
of BSID-II. BSID-II is an evaluation tool for assessing the
developmental status of individual children. It consists
of mental, motor, and behavior rating scales. Cognitive
domain of BSID-II provides developmental age of mental
status. The appropriate age of the BSID-II is between 1
and 42 months. However, it is also applicable to children
over 42 months of age with developmental delay if their
function is below their normal counterparts [27,28].
Statistical analysis
Statistical analysis was applied using SPSS version 18
(SPSS Inc., Chicago, IL, USA). The Mann-Whitney test
and Fisher exact test were used to compare baseline char-
acteristics and initial functional states of the two groups.

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The Wilcoxon signed-rank test was performed to identify
within-group changes between pre- and post-treatment.
Mann-Whitney analysis was used to compare changes in
THR and control groups pre- and post-treatment and p-
values less than 0.05 were considered statistically signifi-
cant in all tests.
RESULTS
Baseline characteristics
There was no statistically significant difference in base-
line language or cognitive function between the two
groups (Table 1). Participants’ ages ranged from 6 to 11
years. Their mean age was 8.2±1.7 years in the THR group
and 7.5±1.1 years in the control group. There were 19
participants diagnosed with ASD. The remaining 10 par-
ticipants were diagnosed with ID. REVT was performed
for all study subjects. Although PRES was tried on all sub-
jects, 6 patients in the THR group and 3 patients in the
control group were unable to perform the test because
of their inadequate language skills. In the assessment
of cognitive function, 5 subjects of the THR group and
2 subjects of the control group were evaluated using K-
ABC while the remaining subjects from each group were
evaluated using the cognitive domain of BSID-II.
Pre- and post-treatment measurements
Following the intervention phase, the THR group
showed statistically significant improvements in all as-
pects of receptive and expressive language assessed by
REVT (∆Reception=2.67, p=0.001; ∆Expression=2.94,
p=0.011) and PRES (∆Reception=2.33, p=0.005; ∆Ex-
pression=1.73, p=0.007), as well as cognitive function
assessed by the cognitive domain of BSID-II (∆=3.31,
p=0.007) and K-ABC (∆=4.60, p=0.042) (Table 2).
After conventional therapy, the control group also
showed significant improvements in receptive language
function assessed by REVT (∆=1.45, p=0.027) and cogni-
tive function assessed by the cognitive domain of BSID-II
(∆=2.33, p=0.042). These improvements were to a lower
extent than those in the THR group (Table 2).
When we compared score changes in THR group and
control group, there were no statistically significant dif-
ferences (Table 2). Although between-group comparison
did not reveal statistically significant difference, the THR
group showed statistically significant post-treatment im-
provements in more items than the control group.
Analysis according to diagnosis (ASD vs. ID)
We also performed data analyses according to diagnosis
(ASD or ID). In the ASD group (nTHR=12, nControl=9), THR
was associated with a statistically significant improve-
ment in language function. Subjects with ASD demon-
strated improvements in both REVT-R (∆=2.83, p=0.07)
and REVT-E (∆=3.25, p=0.027) after THR. Language func-
tion evaluated by PRES also improved after THR among
Table 1. Baseline status of THR and control groups
THR (n=18) Control group
(n=11) p-value
Age (yr) 8.2±1.7 7.5±1.1 0.317a)
Gender 0.466b)
Male 11 5
Female 7 6
Diagnosis 1.000b)
ASD 12 7
ID 6 4
Language
REVT
Reception 17.44±19.97
(n=18)
13.82±18.21
(n=11)
0.611a)
Expression 14.28±20.60
(n=18)
8.82±17.59
(n=11)
0.674a)
PRES
Reception 21.33±13.32
(n=12)
17.00±12.20
(n=8)
0.473a)
Expression 15.58±13.13
(n=12)
10.88±10.44
(n=8)
0.343a)
Cognition
Cognitive
domain of
BSID-II
130.38±21.87
(n=13)
136.00±19.51
(n=9)
0.471a)
K-ABC 68.60±19.41
(n=5)
66.00±31.11
(n=2)
0.857a)
Values are presented as mean±standard deviation or
number (%).
THR, therapeutic horseback riding; ASD, autism spec-
trum disorder; ID, intellectual disability; REVT, Receptive
and Expressive Vocabulary Test; PRES, Preschool Recep-
tive-Expressive Language Scale; BSID-II, Bayley Scales
of Infant Development-II; K-ABC, Kaufman Assessment
Battery for Children.
a)Mann-Whitney test, b)Fisher exact test.

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participants with ASD, both in terms of reception (∆=2.43,
p=0.027) and expression (∆=1.86, p=0.027) (Table 3).
There was no significant improvement in cognitive func-
tion after THR among children with ASD. Participants
with ASD who did not receive THR did not demonstrate
statistically significant improvements in any of these
evaluated domains. Among children with ASD, changes
in language function demonstrated by subjects who un-
derwent THR were not significantly different from chang-
es demonstrated by controls.
The ID group (nTHR=6, nControl=4) demonstrated statisti-
cally significant improvements in receptive vocabulary
Table 3. Therapeutic effects of THR in each disease group, autism spectrum disorder, and intellectual disability
Evaluation
Autism spectrum disorder Intellectual disability
No. of
patients Baseline 8 weeks p-value No. of
patients Baseline 8 weeks p-value
Language
REVT
Reception 12 16.58±20.76 19.42±21.57 0.007* 6 19.17±20.06 21.50±21.19 0.042*
Expression 12 16.25±21.60 19.50±26.12 0.027* 6 10.33±19.69 12.67±24.06 0.180
PRES
Reception 7 22.43±14.02 24.86±14.47 0.027* 5 19.80±13.72 22.00±14.51 0.066
Expression 7 16.86±13.58 18.71±14.49 0.027* 5 13.80±13.81 18.75±14.22 0.109
Cognition
Cognitive domain
of BSID-II
8 130.00±22.10 133.00±24.34 0.063 5 131.00±24.05 134.80±24.33 0.042*
K-ABC 4 66.50±21.75 70.75±23.98 0.066 1 77.00 83.00 -
Values are presented as mean±standard deviation.
THR, therapeutic horseback riding; REVT, Receptive and Expressive Vocabulary Test; PRES, Preschool Receptive-
Expressive Language Scale; BSID-II, Bayley Scales of Infant Development-II; K-ABC, Kaufman Assessment Battery for
Children.
*p<0.05 by Wilcoxon signed-rank test.
Table 2. Therapeutic effects of THR and conventional therapy
Evaluation Baseline 8 weeks ∆ Post-Pre p-valuec)
THR Control THR Control THR Control
Language
REVT
Reception 17.44±19.97 13.82±18.21 20.11±20.84a) 15.27±18.12b) 2.67±2.35 1.45±1.81 0.188
Expression 14.28±20.60 8.82±17.59 17.22±24.95b) 9.64±17.62 2.94±5.03 0.82±2.44 0.238
PRES
Reception 21.33±13.32 17.00±12.20 23.67±13.89a) 17.88±12.41 2.33±1.83 0.87±1.46 0.069
Expression 15.58±13.13 10.88±10.44 17.17±14.10a) 11.75±10.08 1.58±1.31 0.88±1.46 0.208
Cognition
Cognitive domain
of BSID-II
130.38±21.87 136.00±19.51 133.69±23.29a) 138.33±20.20b) 3.31±3.88 2.33±3.32 0.556
K-ABC 68.60±19.41 66.00±31.11 73.20±21.48b) 70.00±36.77 4.60±2.88 4.00±5.66 1.000
Values are presented as mean±standard deviation.
THR, therapeutic horseback riding; ASD, autism spectrum disorder; ID, intellectual disability; REVT, Receptive and
Expressive Vocabulary Test; PRES, Preschool Receptive-Expressive Language Scale; BSID-II, Bayley Scales of Infant
Development-II; K-ABC, Kaufman Assessment Battery for Children.
a)p<0.01 and b)p<0.05 by Wilcoxon signed-rank test, c)Mann-Whitney test.

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ability assessed by REVT-R (∆=2.33, p=0.042) and cogni-
tive function assessed by the cognitive domain of BSID
II (∆=3.80, p=0.042) after THR (Table 3). However, no
significant change was observed among children with ID
who did not undergo THR. As with ASD, among partici-
pants with ID, changes in language or cognitive function
demonstrated by subjects who underwent THR were not
significantly different from changes demonstrated by
controls.
DISCUSSION
This case-control study of 29 patients diagnosed with
ASD or ID compared a group who participated in an
8-week THR intervention to a control group who contin-
ued conventional therapy. Both groups showed improve-
ments in language and cognition following the interven-
tion phase. However, the THR group showed statistically
significant improvements in more items than the control
group. In between-group comparison, the degree of im-
provements (∆Post-Pre) was not statistically significantly
greater in the THR group.
Results of the current study were consistent with previ-
ous studies suggesting that THR might affect language
skills of children with ASD [11]. In a randomized con-
trolled study, Gabriels et al. [11] have assessed behavioral
and language-related outcomes of THR using Aberrant
Behavior Checklist-Community (ABC-C), Social Respon-
siveness Scale (SRS), Systematic Analysis of Language
Transcripts (SALT), and Peabody Picture Vocabulary
Test-fourth edition (PPVT-4). Greater improvements
were observed in the THR group compared to controls in
terms of behavior, social communication, and expressive
vocabulary. Additionally, they reported improvements
in social cognition evaluated with SRS and rated by care-
giver. Although SRS is a commonly used tool for ASD, it
might be considered an insufficient indicator of effects of
THR on cognition. To the best of our knowledge, this is
the first study to show positive effects of THR on cognitive
function using objective testing methods, K-ABC, and the
cognitive domain of BSID-II.
To our knowledge, there has been no published study
evaluating effects of THR on children with ID. Our results
suggest potential positive effects of THR on language and
cognitive function among children with ID. Borioni et al.
[13] have divided 23 adults with ID into equestrian reha-
bilitation (ER) and onotherapy groups. Psychologist as-
sessed their participants using a rehabilitation program
developed at their institution (Villa Buon Respiro in Vit-
erbo, Italy), containing autonomy, motor-praxis, neuro-
psychological, affective-rational, cognitive, and com-
munication subscales. Overall, there were improvements
in autonomy and social integration among subjects with
ID who underwent horse and donkey therapy. Cogni-
tion and communication findings varied depending on
the rater. Effects of ER or onotherapy on cognition and
communication were inconclusive. Our results showed
improvements in receptive vocabulary ability assessed by
REVT-R and cognitive function assessed by the cognitive
domain of BSID-II. As with children with ASD, among
participants with ID, improvements in cognitive and lan-
guage skills were not significantly different between those
who received THR and those who did not.
It is not clearly known how THR affects the psychobe-
havior of children with ASD. However, there are several
hypotheses. As existing literature indicates, animals
are crucial in children’s social and cognitive develop-
ment [29,30]. Animal-assisted therapy is known to be
beneficial for children with developmental disorders. It
involves the notion that animals can act as transitional
objects. Children can form primary bonds with animals.
Such bonds can then be transferred to humans [31-33].
In THR, riding is not only a fun activity for participants.
It also involves getting the child out to do an activity
that can facilitate their interactions with both the horse
and other people [33]. Promotion of interactions might
have been a foundation for improvements of pro-social
behavior and communication skills [11,12,34]. More-
over, non-verbal communication between the rider and
horse (with horse constantly responding to the rider’s
body language) may play a role [35]. Through horse’s
responses to the rider’s commands, it might be inferred
that children could learn how his or her communication
affects the horse’s behavior [36]. In addition, during THR,
riders maintain postural control and balance throughout
the riding. These require attention. These experiences
of non-verbal communication and attention might serve
as a platform for improvements in communication skills
and cognition among children with ASD [35,37]. Another
hypothesis about the human–equine experience is that
the warmth of horse’s body and the horse’s rhythmic
movements during riding can contribute to a relaxing

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environment which has a calming effect on children with
ASD [35,36]. This calming effect may reduce irritability
and hyperactivity. It could improve their attention and
potentiate effects of other rehabilitation methods, result-
ing in improved language and cognitive function [11,34].
Rhythmic movements of horses can also stimulate the
vestibular system. Occupational therapy research has
noted that activities stimulating the vestibular system can
promote the production of speech sounds [38,39]. Fur-
thermore, feedback from the instructor, provided when
a child exhibits inappropriate behavior during THR, may
modulate the child’s perception of and reactions to the
surrounding environment and language stimuli. Ryan et
al. [40] have demonstrated that the frequency of such be-
haviors is decreased when THR progresses in their study
of adults with ID, along with improved perception of sur-
roundings and instructions. In a similar context, Borioni
et al. [13] have proposed that therapeutic techniques
involving horses and donkeys can help adults with ID
become more aware of their surroundings owing to con-
sistent responses of animals to human subjects’ actions.
These controlled interactions can facilitate focus among
subjects.
Although the number of subjects was small and there
were several limitations, our study was meaningful in
that it was the first study to investigate effects of THR on
children with ASD or ID, especially in relation to lan-
guage and cognition assessed by objective testing meth-
ods. Furthermore, although the involved mechanisms
and pathways are currently unclear as future research
provides more evidence, THR might be applied as a treat-
ment for children with ASD or ID to help improve their
language and cognitive abilities.
Limitations of this preliminary study include its small
sample size. Furthermore, it might be necessary to con-
duct a longer duration of follow-up assessments after
THR to determine whether these improvements of lan-
guage and cognitive function are temporary or sustained.
If studies with larger sample sizes and longer periods of
follow-up after THR are conducted, effects of THR could
be more definitively elucidated. Another major limitation
was that this study did not control variables of conven-
tional therapy. Although this work is meaningful as a pre-
liminary study, it is necessary to identify effects of THR
on language and cognition through more rigorous, well-
designed studies in the future. Assessment tools used in
this study—REVT, PRES, and BSID-II—are commonly
used for children with language or cognitive impairment.
These tools have been used for objective assessments in
the field of rehabilitation medicine. Findings generated
from them should be interpreted carefully because they
have not been validated to compare baseline and post-
rehabilitation status of such children. In order to increase
the reliability of this study, further validation of these
tools is warranted. Additionally, appropriate protocols for
children with ASD or ID were not fully validated. Further
studies should be conducted to establish the appropriate
number and timing of THR sessions as well as the appro-
priate age to start THR.
In conclusion, THR with conventional therapy in neu-
rodevelopmental disorders specifically ASD and ID was
associated with improvements in almost all domains of
language and cognitive assessment suggesting that THR
with conventional therapy might have positive effects on
language and cognitive impairments. However, improve-
ments associated with THR with conventional therapy
were not statistically significantly different from improve-
ments observed in subjects received who conventional
therapy only. Further well-designed, larger-scale studies
with longer follow-up periods are needed to clearly es-
tablish whether THR is an effective technique to improve
language and cognitive functions of children with ASD
and ID.
CONFLICT OF INTEREST
No potential conflict of interest relevant to this article
was reported.
ACKNOWLEDGMENTS
This study was conducted with financial support from
the Korea Racing Authority.
AUTHOR CONTRIBUTION
Conceptualization: Sung IY. Methodology: Sung IY,
Kwon S, Ko EJ, Kim HS. Formal analysis: Sung IY, Kwon
S. Funding acquisition: Sung IY. Project administration:
IY Sung. Visualization: Kwon S. Writing – original draft:
Kwon S. Writing – review and editing: Sung IY. Approval
of final manuscript: all authors.

Horseback Riding in Children With ASD or ID
287
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