Surface electromyography analysis of contralateral muscle irradiation in proprioceptive neuromuscular facilitation

Abstract Introduction: Proprioceptive neuromuscular facilitation (PNF) is a concept that promotes functional movement through facilitation, inhibition, strengthening, and relaxation of muscle groups. Among its principles, irradiation is defined as the propagation of the response to the stimulus, which can be evidenced as increased contraction or relaxation in synergistic muscles and movement patterns. Objective: To evaluate PNF patterns in muscle irradiation to the contralateral lower limb through surface electromyography in physical therapy students. Methods: This is a cross-sectional study with a quantitative and analytical approach. Thirty healthy volunteers participated in the study and were evaluated with surface electromyography as they performed PNF and rectilinear movement patterns. Results: It was found that PNF patterns radiate to the contralateral limb, with the flexion-abduction-internal rotation pattern with knee flexion being statistically significant (p < 0.05). It was observed that the upper patterns do not significantly irradiate to the contralateral limb when compared with lower limb movements (LL). In the correlation between strength and electromyographic activation, the medial gastrocnemius obtained the greatest strength and the lowest muscle activation in movements involving hip or shoulder flexion. Conclusion: PNF diagonals irradiate to the LL contralateral to that tested in the electromyography. New studies with a larger sample size are needed to investigate contralateral muscle irradiation in healthy individuals through surface electromyography in order to obtain a more robust correlation.