Temporal Motor Coordination in the Ankle Joint Following Upper Motor Neuron Lesions

[Purpose] We compared ankle temporal motor coordination between stroke, spinal disease and healthy elderly groups, and investigated the relationship between motor impairments and gait speed. [Subjects] Twenty-four patients with stroke, 19 post-operative spinal disease patients and 17 healthy elderly subjects participated. [Methods] Ankle temporal motor coordination of the three groups was assessed using the simple reaction time, the foot-tapping test, and a rhythm task. Rhythm error and rhythm variation were analyzed using the results of the rhythm task. Isometric muscle strength, spasticity, muscle stiffness, somatosensory and 10-m gait speed of the stroke and spinal disease subjects were also measured. [Results] Only the stroke group showed significant reductions in temporal accuracy and consistency in the rhythm task. Simple reaction time and the rhythm task were significantly poorer in the stroke group, whereas the foot-tapping test was not. Stepwise multiple regression analysis indicated gait speed was explained by rhythm error and plantarflexor strength in the stroke group, and rhythm error and simple reaction time in the spinal disease group. [Conclusion] Poor performance in simple reaction time and the rhythm task in the stroke group suggest these tasks are controlled by the supraspinal central nervous system. Negative features, particularly motor coordination, are more associated with gait speed than positive features.