Phase- and workload-dependent changes in corticospinal excitability to the biceps and triceps brachii during arm cycling

Abstract

Transcranial magnetic stimulation of the motor cortex and transmastoid electrical stimulation of the corticospinal tract can be used to assess changes in supraspinal and spinal excitability, respectively. These techniques have been used previously to determine differences in the neural control of isometric contractions compared to locomotor outputs. It has been shown that corticospinal excitability to the biceps brachii is not only different between isometric contractions and locomotor outputs, but also different during multiple cadences of arm cycling. This suggests that changes in workload, another method of changing intensity during arm cycling, may also result in differences in corticospinal excitability. The purpose of this study was to examine changes in corticospinal excitability between the biceps and triceps brachii during different relative workloads of arm cycling.