Visual and kinesthetic motor imagery in adults with different degrees of self-reported motor coordination difficulties

: Developmental Coordination Disorder (DCD) involves difficulties in performing coordinated movements with fine and/or gross motor skills deficits. Several studies showed that DCD is characterized by motor imagery deficits as well. Here we investigated in neurotypical adults (N = 334) the relationships between the ease of imaging two main motor imagery components, that is the visual and the kinesthetic one, self-reported motor coordination difficulties and handwriting speed. Self-reported motor difficulties were measured by the Adult Developmental Co-ordination Disorders/Dyspraxia Checklist (ADC) and scores were used to distinguish three groups: participants at risk of DCD (with both relevant childhood and current motor coordination difficulties); with motor coordination difficulties (relevant current but not childhood difficulties); without motor coordination difficulties (neither current nor childhood difficulties). The main results showed more kinesthetic and visual imagery difficulties in participants at risk of DCD than in those both with and without motor coordination difficulties. Interestingly, the relationships between the two imagery components and motor difficulties were different in the three groups, depending on: 1) the developmental phase (childhood or adulthood) to which motor coordination difficulties referred, and 2) the point of view (self or other), from which images were judged. Instead, no relationship was found between imagery abilities and handwriting speed. Thus, a nuanced pattern of the ease of imaging motor imagery emerged in adults with different degrees of self-reported motor coordination difficulties. These findings could be relevant for the assessment of people candidate to undergo a motor imagery training.