Résumé
Introduction: Nerve conduction studies and needle electromyography [EMG] play a central role in the evaluation of patients with neuromuscular disorders. The tibia nerve H-reflex is one of the most common parameters in clinical electro diagnosis, especially in the diagnosis of S1 radiculopathy. H- reflex is important because involvement of S1 root most common in disc hernia causes rapid changes
Objective: The purpose of this study was to determine the mean values of tibia H-reflex in healthy individuals aged 20 years and older
Materials and Methods: In this cross-sectional study 110 asymptomatic volunteers were controlled. All of them were placed in prone position with flexed knee by 20 degree tibia H-reflex latency was recorded by Medelec machine from midcalf on each side. Stimuli were applied at the midpopliteal crease. Data were analyzed by EpiInfo software and by using ANOVA tests to compare means of different groups. The results were reported as mean [CI 95% of mean]
Results: 55.5% were male and 44.5% were female. Mean age of subjects was 41.6 years and mean height was 165.26 cm. The mean H-reflex latency for 220-tibia nerve [110 of right and 110 of left] was 26.46 m/sec [CI 95%=26.62-26.28 m/sec]. The maximum mean H-reflex latency was 28.23 m/sec in over 60 years old age group and the least mean H-reflex latency was 25.93 m/sec in 40-60 years old age group [P<0.0001]. Mean of H-reflex latency were 25.92 m/sec in less than 150 cm height group and was 29.78 m/sec in more than 180 cm height group [P<0.0001]
Conclusion: Since from references, age and height have major effect on normal value of H-reflex latency and this is also evident in this study, and on the side, there is a significant difference in H-reflex values measured in different studies so we recommend the use of normal values according to standardized measurement in each region or clinic