Reliability of soleus H-reflexes in standing and walking post-incomplete spinal cord injury.

Objective: To establish the reliability of soleus H-reflex in individuals with incomplete spinal cord injury (SCI) during the standing and the swing and stance phases of overground walking.

Methods: Fourteen SCI (40 +/- 10 years) and eight noninjured subjects (32 +/- 9 years) participated. The noninjured and SCI subjects walked at self-selected speed overground. H-reflexes in the soleus muscle (at M-wave 7%-13% maximum-M) were tested on two separate days by stimulating the tibial nerve. Intraclass correlation coefficients (two-way mixed model-ICC (1, 2)) and standard error of measurement (SEM) were calculated.

Results: Relative reliability of the H-reflexes was good to excellent; intra-class correlation coefficients (ICCs) ranged from 0.64-0.91 in noninjured and SCI subjects. SEM expressed as percentage of the mean H-reflex was 13%-62% in noninjured and 12%-18% in SCI individuals.

Conclusions: H-reflexes can be reliably assessed in standing and walking in post-SCI and noninjured subjects.

Significance: H-reflexes can be reliably used in longitudinal studies to investigate mechanisms of recovery post-SCI.