Reliance on visual feedback from ocular accommodation on motor skills in children with developmental coordination disorder and typically developing controls

Evaluating handwriting in children with developmental coordination disorder (DCD): Temporal, spatial, pressure and grip-force measures

BACKGROUND

Writing involves complex sensorimotor and biomechanical processes that regulate pressure on the writing surface. Researchers analyze writing to understand kinetics and kinematics by evaluating temporal, spatial, and pressure aspects, yet discerning writing surface pressure and pen-grip force remains challenging.

AIMS

To compare handwriting kinetics (pen grip-force and surface pressure) and kinematics (temporal-spatial) of children with developmental coordination disorder (DCD) with those of typically developing (TD) children.

METHODS AND PROCEDURES

Twenty-seven children with DCD aged 7-12 years and 27 TD children matched by age and gender copied a 29-word passage onto a computerized tablet. Temporal, spatial and surface pressure as well as pen grip-force were measured with a tablet and a wearable device respectively.

OUTCOMES AND RESULTS

The DCD group displayed significantly longer total writing time, mean letter time, and greater letter height, width, variance, spacing, area, and erasures than the TD group. Although there were no significant between-group differences in the surface pressure or maintaining pressure, the DCD group displayed weaker grip-force, p = .01, with greater variance.

CONCLUSIONS AND IMPLICATIONS

The DCD group's weaker grip-force dynamics correlated with reduced legibility, form, and prolonged writing duration, revealing insights into handwriting mechanisms, particularly grip force, crucial for effective clinical interventions.

Enhancing Handwriting Performance of Children with Developmental Coordination Disorder (DCD) Using Computerized Visual Feedback

Recent studies have analyzed the writing metrics of children with developmental coordination disorder (DCD) using computerized systems. To date, the use of computerized visual feedback to improve handwriting has not been investigated. This study aimed to examine the effects of computerized visual feedback on handwriting performance in time, spatial orientation, and pressure indices for children with DCD. Twenty-seven children aged 7 to 12 years with DCD assessed by the Movement Assessment Battery for Children and the Developmental Coordination Disorder Questionnaire received one weekly intervention session for 8 weeks, during which they twice copied an excerpt onto a tablet. Once, they received visual feedback where the writing color corresponded to the degree of pressure on the writing surface, and once they received no visual feedback. The two conditions were counterbalanced throughout the sessions. Pre-intervention sessions were compared with post-intervention sessions and with new texts for time, spatial orientation, and pressure measures. The findings revealed significantly decreased total and mean letter writing, in-air, and writing time and increased capacity in the visual feedback condition. In the spatial variables, a significant decrease in letter height variance was found. Pressure increased significantly throughout the intervention with visual feedback, whereas it decreased post-test in the writing task in both conditions and was maintained in the new text. Visual feedback intervention can increase the kinesthetic-haptic feedback required to regulate pressure during writing, promoting more efficient feedforward processes and improving output quality and capacity. The training effectiveness was transferable, and the intervention accessibility could increase student autonomy.

Motor Skills and Visual Deficits in Developmental Coordination Disorder: A Narrative Review

BACKGROUND

Developmental coordination disorder (DCD) is a developmental disorder in which numerous comorbidities seem to coexist, such as motor and visual impairment and some executive functions; Methods: A narrative review on motor and visual deficits in children with DCD was carried out; Results and Discussion: Fine and gross motor skills are affected in children with DCD. In addition, they seem to be related to visual deficits, such as difficulty in visual perception, sensory processing and visual memory. Limitations have also been found in accommodation. Interventions in children with DCD should be aimed at improving both aspects, since vision affects motor skills and vice versa; Conclusions: In children with DCD, who present a marked deficit in global shape processing, it causes an association between deficiencies in visual perception and motor skills.

Developmental Coordination Disorder and Most Prevalent Comorbidities: A Narrative Review

This narrative review describes, in detail, the relationships between Developmental Coordination Disorder (DCD) and most prevalent associated comorbidities in their complexity, heterogeneity and multifactoriality. The research has been conducted on the main scientific databases, excluding single case papers. Blurred borders between the different nosographic entities have been described and advances in this field have been highlighted. In this multifaceted framework a specific profiling for co-occurring DCD, ADHD and ASD signs and symptoms is proposed, confirming the need for a multidisciplinary approach to define new diagnostic paradigms in early childhood.