Table 8.

The relationship between physical activity and risks/harm

# of studies	Design	Quality assessment					# of participants	Absolute effect	Quality
		Risk of bias	Inconsistency	Indirectness	Imprecision	Other
Mean baseline age ranged from 7.4 weeks-24 months; where mean age was not reported, baseline age ranged from 2 months-4.5 years. Data were collected by case cross-over and longitudinal with 4.5-6.5 years follow-up, case control, and cross-sectional study designs. Risks/harm was assessed as injury risk (proxy-report; Participant Event Monitoring method), injury severity (proxy-report; minor injury severity scale), fracture incidence (proxy-report), and plagiocephaly (objectively measured).
1	Case cross-overa	Serious risk of biasb	No serious inconsistency	No serious indirectness	No serious imprecision	None	170	TPA was unfavourably associated with injury risk but was not associated with injury severity [128].	LOWc
1	Longitudinald	Serious risk of biase	No serious inconsistency	Serious indirectnessf	No serious imprecision	Dose-response evidenceg	2692	Outdoor time was favourably associated with fracture incidence in the winter but unfavourably associated with fracture incidence in the summer [129].	VERY LOWh
1	Case-controli	Serious risk of biasj	No serious inconsistency	No serious indirectness	No serious imprecision	None	194	TPA was favourably associated with plagiocephaly (at present but not at 6 weeks of age) [130]. Prone position was favourably associated with plagiocephaly (for ≥ 5 min/day but not whether it was provided or not) at 6 weeks of age [130].	VERY LOWk
1	Cross-sectionall	Serious risk of biasm	No serious inconsistency	No serious indirectness	No serious imprecision	None	380	Prone position was not associated with plagiocephaly [131].	VERY LOWn

min: minutes; TPA: total physical activity

^aIncludes 1 case cross-over study [128]

^bConvenience sample

^cQuality of evidence remained at “low”

^dIncludes 1 longitudinal study [129]

^eNo psychometric properties were reported for outdoor time and fracture incidence, and there was a large unexplained loss to follow-up

^fOutdoor time was the measure of physical activity

^gDose-response evidence was observed for higher outdoor time with lower fracture incidence

^hQuality of evidence was downgraded from “low” to “very low” because of serious risk of bias and serious indirectness; because of these limitations, was not upgraded for dose-response evidence

ⁱIncludes 1 case-control study [130]

^jNo psychometric properties were reported for the subjective physical activity measures

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

^lIncludes 1 cross-sectional study [131]

^mConvenience sample and no psychometric properties were reported for the subjective physical activity measure

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