Jafarnezhadgero 2018.

Study characteristics
Methods	Randomised controlled two‐arm parallel trial
Participants	30 healthy boys, with flexible flat feet Age: 8 to 12 years Gender: all boys Location: not clear ‐ boys 'recruited from orthopaedic specialists in local community' (p 4) Setting: not clear, ethics approval and trial registry within Iran (p 4) Inclusion criteria: boys who volunteered, flat feet assessed using navicular drop, arch height index, RCSP Exclusion criteria: history of bone fractures, signs of functional lower limb instability, ligament injury, reconstruction of ligaments, neuromuscular dysfunction, dysfunction of lower limb muscles, leg length differences larger than 1 cm, and a history of lower extremity trauma or surgery. Baseline characteristics: all were right foot dominant, no significant baseline differences between groups for examined variables
Interventions	Treatment group (N = 15): medial arch support foot orthoses (custom made medial arch support foot orthoses), CFOs Control group (N = 15): flat 2‐mm thick insoles (sham)
Outcomes	Gait kinematics and ground reaction forces (kinetic) ‐ joint vectors, moments, and ground reaction forces
Source of funding	Deutsche Forschungsgemeinschaft (DFG), and Open Access Publishing Fund of University of Potsdam, Germany.
Notes	All participants issued with same footwear (New Balance 759)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Says only ‘The block randomization method was used to allocate study participants into experimental groups.’
Allocation concealment (selection bias)	Unclear risk	Says only; ‘Another naïve examiner controlled the allocation of each participant and was responsible for delivering the treatment to both groups.’ Not enough information to determine risk.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Sham orthoses used
Blinding of outcome assessment (detection bias) ‐ self‐reported outcomes (e.g., pain, function)	High risk	Due to nature of intervention
Blinding of outcome assessment (detection bias) ‐ objective outcomes	Low risk	Examiners blinded for all outcomes
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data
Selective reporting (reporting bias)	Unclear risk	Iranian Registry of Clinical Trials (IRCT2017082235517N1; URL: www.irct.ir/user/trial/26811/ view) ‐ unable to access the online trial registry.
Other bias	Low risk	none apparent