Soleus H-Reflex and Its Modulation With Vibration in Idiopathic Toe Walkers and Typically Developing Children

Abstract

Idiopathic toe walking is a relatively common developmental condition often leading to secondary problems such as pain and muscle contractures in the lower extremities. The cause of idiopathic toe walking is unknown, which hinders the development of treatment strategies. To test whether children with idiopathic toe walking have functional alterations in their spinal motor circuits, we studied the properties of the soleus H-reflex and its modulation with vibration in 26 idiopathic toe walkers and 16 typically developing children. At the group level, the H-reflex properties did not differ, but at the individual level, in 7 of 25 idiopathic toe walkers, some of the H-reflex parameters fell out of normal limits of typically developing children. However, the H-reflex was suppressed by vibration to the Achilles tendon similarly in both the idiopathic toe walkers and typically developing children. In conclusion, idiopathic toe walking in some children can be associated with functional alterations in their spinal motor circuits.