Joint position sense of lower extremities is impaired and correlated with balance function in children with developmental coordination disorder

Objective: To determine the joint position sense of the lower extremities and its relationship with motor function in children with developmental coordination disorder and typically developing children. Methods: A total of 56 participants were recruited; 28 children with developmental coordination disorder (mean age 10.86 years (standard deviation (SD) 1.07); 13 females, 15 males) and 28 typically developing children (mean age 10.96 years (SD 1.18); 12 females, 16 males). Knee and ankle joint position sense were assessed using a Biodex isokinetic dynamometer. Joint position acuity was measured by position error (PE) and position error variability (PEV). Motor function was examined using the 2nd edition of Movement Assessment Battery for children (MABC-2) and quantified via sub-scores from 3 MABC-2 domains. Results: Both PE and PEV at knee and ankle joints were significantly greater in children with developmental coordination disorder compared with typically developing children. In addition, both PE and PEV were significantly greater at the ankle joints than the knee joints in children with developmental coordination disorder. For children with developmental coordination disorder only, joint position acuity in the lower extremities significantly and negatively correlated with MABC-2 balance sub-score. Conclusion: This study verifies that lower limb proprioception is impaired in children with developmental coordination disorder. Also, children with developmental coordination disorder displayed greater proprioceptive deficits at the ankle compared with the knee joint. Children with developmental coordination disorder who had poorer joint position acuity, i.e. greater PE and PEV, in the lower extremities tended to perform less well in balance function.