Many experts have used an indirect method for enhancing strength and performance of muscles in clinical practice. The indirect method, which called an irradiation is a basic procedure of proprioceptive neuromuscular facilitation, there is little research related the effects of irradiation. This study investigated abdominal muscle activity during abdominal drawing-in maneuver (ADIM) combined with irradiation variations. The study recruited 42 healthy, young adults who were divided randomly into three groups according to which intervention they received. The first group performed the ADIM combined with coactivation of the pelvic floor muscle. The second group performed the ADIM combined with the irradiation resulting from dorsiflexion of the ankle. The third group performed the ADIM combined with the irradiation resulting from bilateral arm extension. Electromyography data were collected from the rectus abdominis, external oblique abdominis, and transversus abdominis/internal oblique abdominis (TrA/IO) muscles during ADIM combined with irradiation variations. There were significant differences in the abdominal muscle activity and the preferential contraction ratio of the TrA/IO among the three groups (P<0.05). ADIM combined with irradiation resulting from bilateral arm extension may be effective for enhancing the deep and superficial abdominal muscles of healthy people and athletes. The ADIM without the irradiation is advantageous for recovering motor control of the TrA/IO.
Keywords: Ab-dominal drawing-in maneuver; Irradiation; Proprioceptive neuromuscular facilitation.