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

OBJECTIVE To determine the joint position sense of the lower extremities and its relationship with motor function in children with developmental coordination disorder (DCD) and typically developing (TD) children. METHODS A total of 56 participants were recruited; 28 children with DCD (age 10.86±1.07 years; 13 females, 15 males) and 28 TD children (age 10.96±1.18 years; 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 DCD compared with TD children. In addition, both PE and PEV were significantly greater at the ankle joints than the knee joints in children with DCD. For children with DCD 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 DCD. Also, children with DCD displayed greater proprioceptive deficits at the ankle compared with the knee joint. Children with DCD who had poorer joint position acuity, i.e. greater PE and PEV, in the lower extremities tended to perform less well in balance function.