Quantitative motor unit potentials analysis in healty horses

Electromyographic examination (EMG) is a diagnostic technique, useful to discriminate between myogenic and neurogenic problems. In our study we used a multi-MUP EMG analysis, an online method that, permitting to know the results in real time, may be advantageous especially in uncooperative and not sedated animals. The EMG examination was performed in ten healthy horses on splenius, trapezius and triceps muscles, using concentric needle electrodes. The signals were acquired and analyzed online with a dedicated software that proposed son)e grouping of the motor unit potentials (MUPs). For each subset of MUPs the program analysed duration, amplitude, area/amplitude ratio and firing rate. The results indicate that no significant differences have been evidenced among the three muscles studied. The MUPs had a duration of 8.04 ms ± 2.32 (S.D.) in splenius, 7.85 ms ± 2.61 (S.D.) in trapezius and 7.35 ms ± 2.32 (S.D.) in triceps, while amplitude values were 2.52 μV ± 0.22 (S.D.) in splenius, 2.56 μV ± 0.21 (S.D.) in trapezius and 2.59 μV ± 0.29 (S.D.) in triceps. The plotting of amplitude versus duration, for all three muscles studied, showed a homogeneous range of normality. We believe that the present method may be adopted to create a normative data base for evaluation of muscular function in clinical studies.