Deficits in Proprioception Measured in Children With Somatodyspraxia

PURPOSE: We examine proprioceptive abilities in children with dyspraxia compared with age-matched controls. We hypothesize that children with dyspraxia will show reduced proprioceptive awareness contributing to their difficulty in motor control.

BACKGROUND: Deficits in sensory processing, particularly proprioception, can severely affect a child’s ability to learn motor skills, presenting as dyspraxia and affecting activities of daily living. Traditionally, assessments of sensory abilities have primarily been behaviorally based, focusing on problematic behavioral outcomes. Concerns had been raised about the reliability of observer-based assessments of sensation.

DESIGN: We used a quasi-experimental design with two groups (dyspraxia, age-matched controls). Each group was assessed with proprioceptive tests.

PARTICIPANTS: We recruited 9 children with somatodyspraxia (6–8 yr old, mean [M] = 7.1) and 9 typically developing children (6–8 yr old, M = 7.6) from the University of Southern California and University of Illinois at Chicago and surrounding areas. We obtained informed assent and consent from the participants and their parents.

METHOD: The Sensory Processing Measure (SPM) was used to characterize the children’s sensory-related behavioral patterns as measured by parents’ reports. Motor coordination in the hands and ability to imitate hand patterns with and without vision was measured with the Test of Hand Gestures. Joint position sense was assessed by asking the child to match an arrow to the positions of the wrist and elbow using a custom-made apparatus. Force perception was assessed by matching grip and pinch forces unilaterally to a target and bilaterally without visual feedback using electronic dynamometers.

ANALYSIS: One-way analysis of variance tests were used to examine the difference between the two groups. For joint position sense and force perception, the performance baseline was established using control group data. Individual participant data in the dyspraxia group were analyzed in comparison to the control group.

RESULTS: The dyspraxia group scored significantly higher than the control group in the touch, balance and motion, and planning and ideas subscales of the SPM. This group performed significantly poorer in visually identifying different hand gestures, copying hand gestures and finding hand gesture matching pictures without vision of hand. This confirmed difficulties in motor coordination and planning in children with dyspraxia.

The group differences in the force perception and joint position sense measures were not statistically different. However, comparing each child in the dyspraxia group with the control group baseline statistics, all 9 of these children had statistically larger errors than the control group (2 standard deviations beyond the control mean), in various aspects of the tests. In particular, 5 of the 9 children had this statistical difference in the bilateral matching of forces without visual feedback. Four had this statistical difference for the joint position sense tests. Four had this statistical difference for the unilateral force matching with visual feedback tests.

DISCUSSION: Our results demonstrate that difficulties with various proprioceptive abilities, such as force perception and joint position sense, can contribute to difficulties in motor control and coordination, key characteristics of dyspraxia. Our methods will allow therapists to isolate the specific proprioceptive difficulties a child with dyspraxia has, which facilitates targeted intervention.

IMPACT STATEMENT: The assessments presented in this study allow for better understanding of the underlying proprioceptive ability of a child who presents with dyspraxia. A more well-rounded evaluation will allow for more targeted intervention planning.