No effect of skin anesthesia on pain intensity ratings associated with elicitation of the H-reflex in the soleus muscle.
This experiment evaluated the effect of a topical anesthetic on the intensity of pain experienced in response to elicitation of the H-reflex in the soleus muscle. Ten college-aged males provided ratings of pain intensity in response to elicitation of the H-reflex before and after topical application of skin anesthetic (5g EMLA) or placebo cream at the site of electrical stimulation in the popliteal fossa. The results indicated that (1) pain was experienced in association with the elicitation of both the H-wave and M-wave components of the H-reflex, and the skin anesthetic did not impact the pain intensity ratings; and (2) the skin anesthetic did not impact the amplitude of the H-wave, M-wave, and H/M Ratio recorded in the soleus muscle. The authors conclude that elicitation of the H-reflex in the soleus muscle results in low intensity pain, and the pain appears to be caused by activation of subcutaneous nociceptive afferent fibers of the tibial nerve.
Motl
Robert W
RW
Department of Exercise Science, University of Georgia, Athens, USA. robmotl@uiuc.edu
O'Connor
Patrick J
PJ
Knowles
B David
BD
D000287:Administration, Topical; D000328:Adult; D019162:Anesthetics, Combined / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001132:Arm / Q000503:physiopathology; D004558:Electric Stimulation; D006181:H-Reflex / Q000187:drug effects*; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D000077442:Lidocaine, Prilocaine Drug Combination; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000503:physiopathology; D010147:Pain Measurement / Q000187:drug effects*; D011318:Prilocaine / Q000008:administration & dosage*; D012016:Reference Values; D012867:Skin / Q000187:drug effects
D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D000077442:Lidocaine, Prilocaine Drug Combination; D011318:Prilocaine; D008012:Lidocaine