Table 1.

Summaries of the present study.

Author (Year)	Title	ASD Participants	Motor Tests	Social Tests	Other Tests	Results
Associated
MacDonald M. et al. (2013) [13]	The relationship of motor skills and adaptive behavior skills in young children with autism spectrum disorders	ASD194 children (157 M, 37 F) aged 14-49 monthsnon-ASD (DD)39 children (M 27 F 12) in the same age range	•Mullen scales of early learning •gross motor skills •fine motor skills	The Vineland Adaptive Behavior Scales, 2nd Ed.		•Fine motor skills and calibrated autism severity were significant predictors of adapted behavior composite, daily living skills, adaptive social skills, and adaptive communicative skills. •Gross motor skills as predictors of daily living skills.
Kim H. et al. (2016) [21]	Relations among motor, social, and cognitive skills in pre-kindergarten children with developmental disabilities	ASD •373 children, ages between 3.55 and 5.70 years old	•Learning Accomplishment Profile-Diagnostic •gross motor •body movement •object movement •fine motor •manipulation •writing	•Devereux Early Childhood Assessment •initiative •self-control •responses	•Learning Accomplishment Profile-Diagnostic •cognitive •language •naming •comprehension	•Neither gross motor nor fine motor skills significantly predicted improvements in their cognitive skills or social skills.
Pusponegoro H.D. et al (2016) [22]	Gross Motor Profile and Its Association with Socialization Skills in Children with Autism Spectrum Disorders.	ASD •40 children aged between 18 months and 6 years TD •40 children aged 18 months-6 years	•Vineland Adaptive Behavior Scales, 2nd Edition; Gross motor subdomain	•Vineland-II; Socialization subdomain		•Low socialization scores in the children with ASD who had poor gross motor skills. •Did not find an independent association between gross motor impairments and socialization skills.
Hannant P. et al. (2016) [23]	Sensorimotor Difficulties Are Associated with the Severity of Autism Spectrum Conditions	ASD 18 children (13 M, 5 F) aged 7–16 years TD 18 children (7 M, 11 F) aged 6–12 years	•The Movement Assessment Battery for Children—2 •manual dexterity •ball skills •static and dynamic balance •The Beery-Buktenica Developmental Test of Visual-Motor Integration, Sixth Edition •visual motor integration •visual perception •fine motor coordination	•British Picture Vocabulary Scale-Third Edition •receptive language •The Social Communication Questionnaire (Lifetime form) •Autism Diagnostic Observation Schedule-2nd Edition •Autism Diagnostic Interview-Revised	•Sensory Profile •sensory responsivity •modulation •behavioral emotional response •Wechsler Abbreviated Scale of Intelligence-2nd Edition •verbal and non-verbal intelligence	•The MABC2 significantly correlated with the ADOS-2 with medium to large effect. •The MABC2 did not correlate with the ADI-R or SCQ.
Craig F. et al. (2018) [24]	Motor competency and social communication skills in preschool children with autism spectrum disorder.	ASD + ID 46 children between 3-6 years ID 42 children aged 3–6 years	•Movement Assessment Battery for Children-second edition (MABC-2) •manual dexterity •aiming and catching •balance	•Social Communication Questionnaire	•Leiter International Performances Scale Revised (Leiter-R) —IQ level	•In the ASD+ID group, a significant negative correlation between MABC-2 aiming and catching scores with SCQ scores. •MABC-2 total test scores correlated negatively with SCQ scores.
Hirata S. et al. (2014) [25]	Relationship between motor skill and social impairment in children with autism spectrum disorders	ASD 26 children aged 7–16 years with the IQ between 73-124	•Movement Assessment Battery for Children-second edition (MABC-2) •manual dexterity •aiming and catching •balance	•Social Responsiveness Scale		•The manual dexterity standard score was significantly correlated negatively with the SRS T-score. •The correlation between the MABC-2 total standard score and SRS total score was moderately high, but it did not reach the significance level.
Mody M. et al. (2017) [26]	Communication Deficits and the Motor System: Exploring Patterns of Associations in Autism Spectrum Disorder	ASD 1781 children aged 2–15.5 years, with all IQ levels (gender composition not specified)	•Vineland Adaptive Behavior Scale-Second Edition(VABS); Gross motor subdomains •Mullen Scales of Early Learning; Fine motor scales	•Mullen Scales of Early Learning -expressive/receptive languages •VABS; Interpersonal subdominant •Autism Diagnostic Observation Schedule -quality of social overtures		•Both GM and FM skills were found to be significantly associated with social interaction skills. •There was a significant negative association between QSOV scores and fine motor raw scores but not gross motor raw scores. •There was no significant association of QSOV scores with gross motor skills.
Hsu H.C. et al. (2004) [27]	The relationship of social function with motor and speech functions in children with autism	ASD 32 children (27 M, 5 F) (mean age, 44.5 months) (mean age, 44.9 months)	Chinese Children Developmental Inventory •Gross Motor •Fine Motor	Chinese Children Developmental Inventory •expressive language •concept comprehension •social comprehension •personal social		•Pearson’s correlation coefficient showing that all achieved statistical significance. •Using a stepwise linear regression test, the results showed the PS function was highly correlated with SC. •The remaining variables of GM, FM, EL, and CC did not significantly increase the association.
MacDonald M. et al. (2013) [28]	Motor Skills and Social Communicative Skills in School-Aged Children With Autism Spectrum Disorder	ASD 23 high-functioning and 12 PDD-NOS, aged 6–15 years old with the IQ above 64	•Test of Gross Motor Development-2 •locomotor skills •object control skills	•Social Skills Improvement System Rating Scales •Calibrated ASD severity score		•Total raw motor skill scores were not a significant predictor of calibrated ASD severity holding all other variables in this model constant. •Object-control motor skills significantly predicted calibrated ASD severity. •Neither the locomotor or object-control subscale predicted standardized social skills.
Holloway J.M. et al. (2018) [29]	Relationships Between Gross Motor Skills and Social Function in Young Boys With Autism Spectrum Disorder	ASD 21 boys aged 48–71 months, previously diagnosed as having ASD	•Peabody Developmental Motor Scales Second Edition (PDMS2) -gross motor skills •stationary •locomotion •object manipulation •Miller Function and Participation Scales (M-FUN) -gross motor skills •motor accuracy •motor planning •stability •balance and equilibrium •weight shifting	•The Social Skills Improvement System Rating Scales(SSIS) •social skills •problem behaviors		•Moderately high correlations were found between the overall PDMS2 motor quotient and the overall SSIS score. •Moderately high correlations were also found between the M-FUN motor score and the overall SSIS score. •There were moderate, positive correlations between the overall motor score and the communication, assertion, empathy, and engagement subtests. •No significant relationships were found between overall motor and SSIS problem behaviors. •All subtests of the PDMS-2 had positive, moderate correlations with the overall social score. Motor accuracy and stability had moderate, negative correlations with overall social scores.
Travers B.G. et al. (2015) [30]	Brainstem White Matter Predicts Individual Differences in Manual Motor Difficulties and Symptom Severity in Autism.	ASD 67 males aged 5–39 years TD 42 males aged 5–39 years	Fine motor •grip strength •finger tapping speed	•Social Responsiveness Scale	IQ - Differential Abilities Scales, WISC-III, WAIS-III	•Weaker grip strength was significantly correlated with more severe autism symptoms in the ASD group, and slower finger tapping was marginally correlated with more severe autistic traits in the ASD group.
Bishop-Fitzpatrick L. (2017) [31]	Correlates of Social Functioning in Autism Spectrum Disorder: The Role of Social Cognition	ASD 108 individuals aged 9–27.5 years old with normal IQ	Fine motor skills •speed - finger tapping for the dominant hand •manipulative - grooved pegboard test for the dominant hand	•Vineland Adaptive Behavior Scales •Socialization domain •Child Behavior Checklist/4–18 •Social Problems •does not get along with other kids •gets teased a lot	Social cognition (Theory of Mind) •Sally-Anne experiment •first-order false-belief task •John-Mary experiment •Peter-Jane experiment •second-order false-belief task	•Greater social cognition, but not motor function, was significantly associated with better social functioning when controlling for sex, age, and intelligence quotient.
Dadgar H. et al. (2017) [32]	The Relationship between Motor, Imitation, and Early Social Communication Skills in Children with Autism.	ASD 20 children aged 3–5 years old	•Test of Gross Motor Development-2 •locomotor skills •object control skills	•Early social communication scale (ESCS) •initiating joint attention (IJA) •responding to joint attention (RJA) •initiating behavioral requests (IBR) •responding to behavioral requests (RBR) •initiating social interaction (ISI) •responding to social interaction (RSI)	•Motor Imitation Scale	•A significant correlation was obtained between TGMD-2 object control subtest with IJA, RJA, and IBR, but not with RBR, ISI, and RSI. •The correlation between TGMD-2 locomotor subtests with ESCS subscales was not significant.
Travers B.G. et al. (2013) [33]	Motor difficulties in Autism Spectrum Disorder: Linking Symptom Severity and Postural Stability	ASD •26 adolescents and adults (24 M, 2 F) aged between 16 years 8 months to 28 years 10 months TD •26 participants (24 M, 2 F) aged between 18 years 2 months to 30 years 10 months with an IQ of 80 and over	•Nintendo® Wii balance board •Postural Stability •Visual input condition (eyes open or eyes closed), and the number of legs used (one or two).	•Social Responsiveness Scale •Repetitive Behavior Scale-Revised	•Wechsler Abbreviated Scale of Intelligence-IQ	•The SRS demonstrated a small-sized, non-significant correlation with postural asymmetry with eyes opened, but a medium-sized, marginally significant correlation with postural asymmetry during eyes closed. •There was a trend for more asymmetrical standing to be associated with greater social symptom severity, but this relation did not reach significance.
Colombo-Dougovito A.M. et al. (2017) [34]	Exploring the interaction of motor and social skills with autism severity using the SFARI Dataset	444 children with autism (more severe) and 39 with ASD (less severe) aged between 48–150 months.	•Vineland Adaptive Behavior Scales, 2nd Edition; Gross motor subdomains	•Social Responsiveness Scale		•Effect sizes further demonstrate a very weak association between gross motor and social skills and group severity. •The association between social skills and gross motor abilities revealed as very weak and nonsignificant.
MacDonald M. et al. (2014) [35]	Motor skills and calibrated autism severity in young children with autism spectrum disorder.	ASD 136 children aged 14 (12)–33 months non-ASD (DD) 23 children in the same age range	•Mullen scales of early learning •gross motor skills •fine motor skills	•Calibrated Autism severity scores		•Gross motor skills were related to calibrated autism severity. •Fine motor skills were related to calibrated autism severity. •Effect sizes were small for both fine and gross motor skills.

ASD, autism spectrum disorder; TD, typically developing; ID, intellectual disabilities.