Table 2.

The relationship between physical activity and motor development

# of studies	Design	Quality assessment					# of participants	Absolute effect	Quality
		Risk of bias	Inconsistency	Indirectness	Imprecision	Other
Mean baseline age ranged from 18.3 weeks-59.79 months; where mean age was not reported, baseline age ranged from 0 months-5 years. Data were collected by RCT, clustered RCT, non-randomized intervention, longitudinal with up to 20-month follow-up, and cross-sectional study designs. Motor development was assessed by fundamental movement skills/motor ability/motor performance/motor development/motor skills/gross-motor development/psychomotor skills (objectively measured; Test of Gross Motor Development – 2, movement assessment battery, Movement Assessment Battery for Children – 2, APM-Inventory, Dutch Second Edition of the Bayley Scales of Infant and Toddler – 3, Motoriktestfürvier-bissechsjährige Kinder 4-6; 12-m run, standing long jump, Motor Test Battery 3-7, Alberta Infant Motor Scales, neurological examination technique for toddler-age, Children’s Activity and Movement in Preschool Study Motor Skill Protocol, Comprehensive Developmental Inventory for Infants and Toddlers, Gessel Development Schedules – Development Quotient, adapted measures from the Zurich Neuromotor Assessment test), achievement of developmental milestones (proxy-report questionnaire), coordination (proxy-report questionnaire), and fine motor coordination/fine motor development (proxy-report interview; Comprehensive Developmental Inventory for Infants and Toddlers).
4	RCTa	Serious risk of biasb	No serious inconsistency	Serious indirectnessc	No serious imprecision	None	705	The PA interventions (planned passive cycling or structured/organized PA) were favourably associated with improved motor development in 3 studies [90–92]. The PA intervention (PA recommendations from nurse) was not associated with improved motor development in 1 study [40].	LOWd
2	Clustered RCTe	Serious risk of biasf	No serious inconsistency	Serious indirectnessg	No serious imprecision	None	1564	The PA intervention (structured/organized PA) was favourably associated with improved motor development (total score and jumping individual score but not for running, hopping, catching, and kicking) in 1 study [33]. The PA intervention (government-led PA program) was not associated with motor development in 1 study [41].	LOWh
6	Non-randomized interventioni	Serious risk of biasj	No serious inconsistency	No serious indirectness	No serious imprecision	None	946	The PA interventions (free play and structured activities, structured/organized PA, dance, or swimming) were favourably associated with improved motor development (boys only and running speed between time 2 and 3 only in 1 study; one-leg balance only in 1 study) in 6 studies [36, 42, 93–96].	VERY LOWk
1	Longitudinall	Serious risk of biasm	No serious inconsistency	No serious indirectness	No serious imprecision	None	197	Prone position was favourably associated with motor development (higher prone duration and gross motor development only at age 6 mo but not at age 24 mo and prone-specific milestones only) [97].	VERY LOWn
10	Cross-sectionalo	Serious risk of biasp	No serious inconsistency	No serious indirectness	No serious imprecision	Exposure/outcome gradientq	1833	TPA was favourably associated with motor development (correlations but not when comparing quartiles of fundamental movement skills in 1 study) in 3 studies [56, 69, 100], unfavourably associated with motor development (running speed only in 1 study) in 2 studies [81, 101], and not associated with motor development in 1 study [86]. LPA was not associated with motor development in 3 studies [67, 86, 100]. LPA 5-min bouts were not associated with motor development in 1 study [86]. MVPA was favourably associated with motor development (total and locomotor [high vs. low only] but not for object control skills in 1 study) in 3 studies [67, 69, 100] and not associated with motor development in 1 study [86]. MVPA 5-min bouts were not associated with motor development in 1 study [86]. VPA was favourably associated with motor development (total and locomotor [high vs. low only] but not for object control skills) in 1 study [67]. Indoor PA was favourably associated with motor development (throwing at target only) in 1 study [81]. Outdoor PA was not associated with motor development in 1 study [81]. Prone position was favourably associated with motor development (gross motor development but not fine motor development in 1 study) in 3 studies [97–99].	VERY LOWr

LPA: light-intensity physical activity; MVPA: moderate- to vigorous-intensity physical activity; PA: physical activity; RCT: randomized controlled trial; TPA: total physical activity; VPA: vigorous-intensity physical activity

^aIncludes 4 RCTs [40, 90–92]

^bNo intention-to-treat analysis; parent-child dyads were excluded if they did not carry out the management plan or if they became sick during the study; and the physical activity program was interrupted in 1 study [90]. Physical activity was not measured, so it is unknown if the intervention resulted in a significant change in physical activity in 3 studies [90–92]

^cThe intervention did not result in a significant change in physical activity in 1 study [40]

^dQuality of evidence was downgraded from “high” to “low” because of serious risk of bias and serious indirectness

^eIncludes 2 clustered RCTs [33, 41]

^fLarge amount of missing data primarily because mean attendance at child care was 48%, and it is unknown if the reason for poor attendance was related to the motor development in 1 study [41]

^gThe intervention did not result in a significant change in physical activity in 1 study [41]

^hQuality of evidence was downgraded from “high” to “low” because of serious risk of bias and serious indirectness

ⁱIncludes 6 non-randomized interventions [36, 42, 93–96]

^jThe outcome was measured post-intervention only in 2 studies [93, 96]. No control group in 1 study [42]. Physical activity was not measured so it is unknown if the intervention resulted in a significant change in physical activity in 6 studies [36, 42, 93–96]

^kQuality of evidence was downgraded from “low” to “very low” because of serious risk of bias

^lIncludes 1 longitudinal study [97]

^mPsychometric properties unknown for the subjective physical activity measures

ⁿQuality of evidence was downgraded from “low” to “very low” because of serious risk of bias

^oIncludes 10 cross-sectional studies [56, 67, 69, 81, 86, 97–101]

^pConvenience sample was used in 6 studies [56, 67, 69, 86, 99, 101]. Psychometric properties unknown for the subjective physical activity measure in 5 studies [56, 97–99, 101], and the outcome measure in 2 studies [69, 101]. Potential confounders were not adjusted for in 7 studies [67, 69, 81, 86, 98, 100, 101]. Large amount of missing motor development data in 1 study [67]

^qA gradient for higher MVPA and VPA with better motor development was observed in 2 studies [67, 100]

^rQuality of evidence was downgraded from “low” to “very low” because of serious risk of bias; because of this limitation, was not upgraded for an exposure/outcome gradient