Congenital idiopathic clubfoot, an isolated birth defect with multifactorial etiology [
1‐
4] has a prevalence in Central Europe and North America of 1–2 in 1000 newborns [
5,
6]. For approximately 50 %, idiopathic clubfoot is bilateral and males are affected more frequently than females [
6,
7]. Typically, the foot is rotated and characterized by midfoot cavus, forefoot adductus and hindfoot equinovarus. Mostly, idiopathic clubfoot is corrected using the Ponseti method [
8,
9], a predominantly conservative treatment with little operative interventions, good functional results and a relapse rate that is comparable to that of other treatments [
10‐
13]. With the goal of sufficient foot mobility, treatment should start as soon as possible after birth. The Ponseti method consists of weekly manipulation and casting, percutaneous Achilles tenotomy (90% of patients) and foot abduction bracing [
8,
9]. Previous studies in infants treated for idiopathic clubfoot revealed some gross motor impairments, especially in the second part of the first year of life, particularly in crawling and walking [
14‐
17]. Additionally, there seems to be some slight deficits in specific cognitive tasks, including problem solving and spatial cognition in clubfoot infants [
14], that parallels the corresponding link between motor and cognitive development in healthy infants [
18‐
21] and infants with locomotor delay due to spina bifida [
22]. Moreover, studies in older children treated for idiopathic clubfoot demonstrated an increased risk of motor activity limitations [
23], gross motor deficits and asymmetrics [
24] as well as a slightly decreased walking capacity [
25]. In contrast, another study did not find any impaired athletic abilities in school-age children after satisfactory treatment of congenital clubfoot [
26]. However, no studies have been made on motor and cognitive abilities in children treated for idiopathic clubfoot at the age of 3 years. Previous studies primary focused on motor development of infants or school-age children with mixed results regarding the long-term recovery from the Ponseti-treatment during infancy. Hence, the aims of this study were to investigate both motor and cognitive abilities among 3-year-old children treated for idiopathic clubfoot with the Bayley Scales of Infant and Toddler Development, third edition [
27].
Based on previous studies [
14‐
17], we expected that children treated for idiopathic clubfoot would be delayed in gross motor development but we did not expect to find any impact on fine motor development. According to a previous study [
23], we did not expect any gross motor differences between children with unilateral and children with bilateral clubfoot. Following previous studies with children treated for spina bifida [
22,
28], we expected that children treated for idiopathic clubfoot could show some deficits in spatial cognitive functioning.