Dyslexia is a developmental disorder frequently associated with motor disorders. This article offers a review of works on motor skills of children and adults with dyslexia. First, comorbidity between dyslexia and Developmental Coordination Disorder (DCD) is very common. Moreover, studies show that these patients have motor dysfunction that can be described as subclinical. This paper categorizes the studies according to areas of motor skills: balance control, fine motor control and eye movements. At the end of the review, we consider in more detail two theories aimed at explaining motor disorders in dyslexia: the atypical brain development theory and the procedural learning disorder theory. In our view, research focused on co-morbidity between learning disabilities and motor disorders should be strengthened. A more integrative approach could help better understand the co-occurrence between neurodevelopmental disorders.

The Little Developmental Coordination Disorder Questionnaire (LDCDQ) is a parental questionnaire designed to identify preschool children at risk of Developmental Coordination Disorder (DCD). This study aimed to translate and cross-culturally adapt the LDCDQ for French European informants (Little Developmental Coordination Disorder Questionnaire-French European [LDCDQ-FE]) and to undertake a pilot examination of its psychometric properties on a French sample. A thorough process of cultural adaptation was completed. The psychometric properties were examined with a sample of 154 French children aged to 5y11m (control = 121; clinically referred = 33). A sub-group of 34 children was assessed using the MABC-2 to measure convergent validity. Principal component analysis demonstrated a four-component structure, accounting for 67.5% of the variance. Internal consistency was acceptable to good (α = 0.74-0.89). Significant correlation between the LDCDQ-FE and the MABC-2 total scores showed convergent validity. Discriminant validity was supported by significant score differences between the clinically referred and a matched control sub-group. Using ROC curves, a cutoff of 67 was proposed for a sensitivity of 81.3% and a specificity of 77.8%. Results show initial evidence of the psychometric properties of the LDCDQ-FE and are encouraging of its use to identify young preschoolers at risk for DCD. In future studies, the test-retest reliability should be investigated, and study sample sizes expanded.

Procedural learning has been mainly tested through motor sequence learning tasks in children with neurodevelopmental disorders, especially with isolated Developmental Coordination Disorder (DCD) and Reading Disorder (RD). Studies on motor adaptation are scarcer and more controversial. This study aimed to compare the performance of children with isolated and associated DCD and RD in a graphomotor adaptation task. In total, 23 children with RD, 16 children with DCD, 19 children with DCD-RD, and 21 typically developing (TD) children wrote trigrams both in the conventional (from left to right) and opposite (from right to left) writing directions. The results show that movement speed and accuracy were more impacted by the adaptation condition (opposite writing direction) in children with neurodevelopmental disorders than TD children. Our results also reveal that children with RD have less difficulty adapting their movement than children with DCD. Children with DCD-RD had the most difficulty, and analysis of their performance suggests a cumulative effect of the two neurodevelopmental disorders in motor adaptation.

Adult-infant early dyadic interactions have been extensively explored by developmental psychologists. Around the age of 2 months, infants already demonstrate complex, delicate and very sensitive behaviors that seem to express their ability to interact and share emotions with their caregivers. This paper presents 3 pilot studies of parent-infant dyadic interaction in various set-ups. The first two present longitudinal data collected on two infants aged between 1 and 6 months and their mothers. We analyzed the development of coordination between them, at the motor and at the vocal level. The 3rd pilot study aims to explore interpersonal coordination in both vocal behavior and motor activity for one infant and his mother at 2, 4 and 6 months. These pilot studies however leave a number of questions open concerning developmental changes and infants’ progressive mastery of interaction. We identify areas worth examining and try to tease out specific issues that may help develop new methodological pathways for the study of early naturalistic social interaction. We assume that a continuous, rather than discrete, approach would better capture the changes taking place in the various communicative modalities, while also displaying each dyad’s specificity and the narrative dimension of social engagement between infants and caregivers.