The Effects of Peripheral Neuropathy on the H-reflex of the Triceps Surae Muscles
Proceedings of the 2020 ISEK Conference
Hoffman's reflex (H-reflex, both H/M ratio and H-index) is affected by peripheral neuropathy (PN). The soleus muscle was the most commonly used muscle for H-reflex study in humans. However, there also reports on the H-reflex of the gastrocnemius muscle in people with PN. The Primary Purpose of the project was to test the relationship of H-reflex parameters among the triceps surae muscles and to compare these relationships between people with PN and healthy controls. The Secondary Purpose of the project was to examine the relationship between H-reflex parameters and functional gait. Methods: Thirteen controls and ten individuals with physician-diagnosed PN were recruited for the experiment. In addition to anthropometrics, the outcome variables were 6-minute walk distance (6MWD), duration of the timed up-and-go test (TUG), and H-reflex of the soleus (SO), medial (MG) and lateral (LG) gastrocnemius muscles of right leg during standing. Significance of ANOVA analysis presented with pvalue and effect size (Cohen's d). The strength of the Pearson's correlation is presented with correlation coefficient (r) and its associated p-value. Results: H/M of SO was significantly greater than that of both MG (p<.001, d=0.232) and LG (p<.001, d=0.098), while no difference in the H-index among the three muscles was detected. The SO H/M ratio was only significantly (r=.872, p=.001) related to that of the LG in the PN group. However, the SO H/M ratio was significantly associated with that of both MG (r=.886, p<.001) and LG (r=.569, p=.042) in the control group. The only significant relationship observed for the H-index was between MG and LG in the control group (r=.779, p=.002). For 6MWD and TUG tests, the PN group walk shorter distances in the 6MWD test (p=.001, d=1.67) and slower in the TUG test (p=.006, d=1.41). 6MWD significantly reduced with the increase of LG H/M ratio (r=-.721, p=.019) for the PN group. And, TUG increased significantly with the H/M ratios of LG (r=.671, p=.034) and SO (r=.639, p=.047) also for the PN group. There was only one significant linear correlation observed for the control group (TUG reduced with the H-index of MG, r=-.579, p=.038). Discussion and Conclusion: SO H/M ratio was greater than that of the MG and LG in both groups consistent with literature for a healthy population. The magnitudes of the SO H/M ratio were proportional to that of the LG. Better functional gait performance associated with reduced H/M ration in people with PN but with increased H-index in controls. PN affected the H-reflex of the triceps surae muscles and their relationship with gait differently. References Makihara, Y., Segal, R. L., Wolpaw, J. R., & Thompson, A. K. (2012). H-reflex modulation in the human medial and lateral gastrocnemii during standing and walking. Muscle & Nerve, 45(1), 116-125. Zhang, S. Q., Manor, B., & Li, L. (2015). H-Index Is Important for Postural Control for People with Impaired Foot Sole Sensation. Plos One, 10(3).
Zhang, Fangtong, Mengzi Sun, Kelsey D. Lewis, Feng Qu, Li Li.
"The Effects of Peripheral Neuropathy on the H-reflex of the Triceps Surae Muscles."
Proceedings of the 2020 ISEK Conference: International Society of Electrophysiology and Kinesiology (ISEK).