title: High Density EMG investigation of H-reflex distribution over the soleus muscle.
abstract: The spatial distribution of H-reflexes over soleus muscle was investigated through High-Density EMG in five healthy subjects. The posterior tibial nerve was stimulated with a staircase current envelope with 1mA steps. The regions where the incremental responses (incremental H-reflexes) occurred were identified for each stimulation step with a validated segmentation algorithm. The average centroid of the segmented areas was located over the Achilles tendon, 5 cm below the myo-tendinous junction of the medial gastrocnemius. The average dimension of these regions corresponded to 28% of the surface covered by the grid of electrodes. The amplitude of H-reflexes recorded in the segmented areas was higher than the average amplitude computed over the entire detection system as well as the H-reflex recorded by the electrode positioned according to SENIAM guidelines. These preliminary results suggest that: i) H-reflex detected from a specific soleus region unlikely reflects the whole muscle volume and ii) H-reflexes with greatest amplitude can be recorded over the Achilles tendon.
authors.forename: Alberto
authors.initials: A
authors.lastname: Botter
authors.forename: Ivan
authors.initials: I
authors.lastname: Vazzoler
authors.forename: Taian M
authors.initials: TM
authors.lastname: Vieira
mesh_terms: D000125:Achilles Tendon / Q000502:physiology; D000465:Algorithms; D004566:Electrodes; D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D013979:Tibial Nerve / Q000502:physiology