The Hoffmann reflex (H reflex) is extensively used to investigate the spinal motor neuron excitability in healthy and pathological subjects. Obtaining a representative and robust amplitude estimation of the H reflex is of marked relevance in clinical as well as in research applications. As for the motor responses, this issue is strictly related to the electrode positioning, especially for large, pinnate muscles such as the triceps surae. In this study we investigated the effect of electrode position on soleus H-reflex amplitude.
The presented results provide a clear indication for electrode positioning, of crucial relevance in applied studies aimed at eliciting H reflexes.