Deficient coordination of associated postural adjustments during a lifting task in children with neurodevelopmental disorders

Abstract

Precision grip and concomitant anticipatory postural adjustments were investigated in 11 children (three females, eight males; mean age 9 years 1 month, SD 11 months) with attention‐deficit‐hyperactivity disorder (ADHD); 12 children (three females, nine males; mean age 9 years, SD 7 months) with developmental coordination disorder (DCD), and 13 children (two females, 11 males; mean age 9 years 9 months, SD 11 months) with a combination of ADHD and DCD (ADHD+). There were two comparison groups: an age‐matched group (four females, 11 males; mean age 9 years 1 month, SD 14 months) and a younger age group (five females, six males; mean age 6 years 5 months, SD 8 months). Adaptation to different weights was evaluated by lifting a specialized grip instrument monitoring grip force, load force, and centre of foot pressure displacements. Children with ADHD+ showed: (1) excessive grip forces, (2) decreased amplitude and prolonged onset of postural adjustments, and (3) reduced ability to adapt the motor output. Children with ADHD and DCD did not scale manual and postural forces in amplitude and time domains. Children with DCD also differed in delayed timing of postural adjustments. Results indicate that children with ADHD and DCD show a spectrum of neural dysfunctions underlying poor motor coordination, which are not specific to the clinical disorder.

Gross motor skills in children with Attention Deficit Hyperactivity Disorder

“…Other findings suggest motor (walking, standing, catching, dribbling, and kicking) that the balance deficits may reflect cerebellar dysfunctions 38,39 and brain abnormalities at higher levels of cognitive, motor, and vestibular integration 40 . In our study, the significant difference between the ADHD and control groups for standing on each leg is supported by literature [41][42][43] . However, one study by Schlee et al 10 found no difference in performance when balancing on one leg.…”

Changes in dynamic balance control over time in children with and without Developmental Coordination Disorder

“…The output of this forward model can then be used in the online control of movement by anticipating the errors (Geuze & Wilson, 2008, Chap. 11;Johnston, Burns, Brauer, & Richardson, 2002;Jucaite, Fernell, Forssberg, & Hadders-Algra, 2003). In our study it seems that children with DCD need more corrections, which due to the timing problems may be too late or too large, resulting in more corrections depicted in erratic reversals.…”

“…This phenomenon corresponds with the cerebellar hypothesis. The cerebellar hypothesis states that motor difficulties in DCD are due to dysfunction of the cerebellum, resulting in delayed response times, poor coincidence timing, poor anticipation of forthcoming disturbances, dysmetria, mirror movements and large within-child variability over learning trials (Jucaite et al, 2003;Kandel, Schwarz & Jessell, 2000;Visser, 2003). For the predictive, feedforward part of the movement the cerebellar adaptive mechanism is important.…”

Aptidão física em crianças com provável transtorno do desenvolvimento da coordenação e índice de massa corporal normal

“…In addition, difficulties in neuromuscular coordination might be related to deficits in force control. There is evidence that children with DCD show some deficits in the production of force and explosive power 27 as well as in force control 28 . Of interest to this study is the fact that an equivalent BMI for children of both groups did not reveal the deficiencies of the p DCD group, giving support to the view that the performance of physical fitness tests in the p DCD group might also be determined by the neuromuscular coordination demands of the tasks.…”