Intramuscular recording of H-reflexes from muscles of the posterior compartment of the lower leg.
This study was designed to elucidate the role of different muscles of the posterior compartment of the lower leg in the generation of the surface-recorded H-reflex. H-reflexes were evoked through percutaneous stimulation of the posterior tibial nerve and recorded concurrently, using monopolar electrodes from the soleus (SOL), medial and lateral gastrocnemii (MG and LG), tibialis posterior (TP), flexor digitorum longus (FDL), and flexor hallucis longus (FHL). There were significant (P less than 0.01) differences in the amplitudes, latencies, and modified H:M ratios of the responses recorded from the different muscles. The SOL modified H:M ratios were consistently the highest (x = 1.02), while the H:M ratios for MG (x = 0.34) and LG (x = 0.37) were consistently the lowest. Latencies of H-reflexes obtained from proximal recording sites (x = 29.2 ms) were significantly shorter than those from the most distal site (x = 31.5 ms). These results establish the contribution made by various deep and superficial muscles to the conventionally recorded H-reflex and help explain the differences in H-reflex amplitudes and latencies when recordings are made from different sites.
Maryniak
O
O
Department of Physical Medicine and Rehabilitation, Faculty of Medicine, University of Western Ontario, London, Canada.
Yaworski
R
R
Hayes
K C
KC
D000328:Adult; D000368:Aged; D004594:Electrophysiology; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D009132:Muscles / Q000033:anatomy & histology / Q000294:innervation* / Q000502:physiology; D009431:Neural Conduction; D011930:Reaction Time