Evaluation of Relationship between Extensor Digitorum Communis Hoffmann‑reflex Latency and Upper Limb Length and Age

The aim of this study was to evaluate the relation between normal values of extensor digitorum communis (EDC) Hoffmann‑reflex (H‑reflex) latency, upper limb length and age in normal participants, and to determine whether there is any regression equation between them.

In this cross‑sectional study, 120 upper limbs of 76 normal volunteers (55 limbs of 34 men and 65 limbs of 42 women) were participated in this study. The onset latency of EDC H‑reflex was determined with standard electrodiagnostic techniques and was recorded.

The mean EDC H‑reflex latency was 15.89 ± 1.41 ms. There was a positive significant correlation between EDC H‑reflex latency and upper limb length (r = 0.749, P < 0.0001) and also arm length (r = 0.758, P < 0.0001), but there was a nonsignificant indirect correlation between age and EDC H‑reflex latency (r = −0.111, P = 0.227). The relation between H‑reflex and sex was not statistically significant (P = 0.46).

According to our result, there are good predictive values between upper limb length and arm length for the estimation of normal EDC H‑reflex latency.