80 Ana C. Panhan, MSc, and Fausto Bérzin, PT, PhD, Department of Morphology (Anatomy), Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil. Mauro Gonçalves, PT, PhD, Giovana D. Eltz, PhD, Marina M. Villalba, and Adalgiso C. Cardozo, PT, PhD, Department of Physical Education, São Paulo State University, Rio Claro, São Paulo, Brazil. Correspondence: Ana C. Panhan, MSc, Morphology (Anatomy), Piracicaba Dental School, University of Campinas, São Paulo, Brazil; carol_panhan@ hotmail.com. Copyright © 2019 J. Michael Ryan Publishing, Inc. htps://doi.org/10.12678/1089-313X.23.2.80 Abstract Physical training has frequently been indicated for ballet dancers to strengthen their trunk muscles, improve their per- formance, and avoid injuries. Te current authors hypothesized that these dancers could beneft from Pilates exercises to stabilize their trunk muscles and improve joint stability and neuromuscular ef- ciency (NME). Our study aimed at evalu- ating the NME and isometric strength of the internal oblique (IO) and multifdus (MU) muscles in a healthy 24-year-old classical ballerina before and after an 8-week Pilates exercise intervention. Te muscles were tested with electromyogra- phy (EMG) and a dynamometer, and the resulting torque and EMG values were used to calculate the NME. Based on the results, the Pilates exercises could improve the NME of the muscles tested, since the torque increased and the EMG activity decreased after the intervention. B allet dancers have been shown to require physical training to strengthen their trunk muscles, improve performance, and avoid injuries, especially those in the lower back. 1-5 Such injuries are estimated to afect 95% of professional ballet dancers, 6-9 who therefore could beneft from exercises developed by Joseph Pilates that are aimed at increasing fexibility and endurance of the “core muscles.” 10-12 Te core is composed of 29 pairs of muscles that support the hip-pelvis-lumbar spine complex. 13 Core stability has been defned as the ability to control the positioning and movement of the trunk over the pelvis and to transfer strength to the upper and lower limbs. 14-20 Pilates exercises have been shown to increase torque 21 and decrease lumbar pain in adult women. 22-28 Tis occurs because those exercises recruit the deep abdominal muscles that stabilize the vertebral segments. 29 To decrease impact on the body’s joints, most Pi- lates exercises are done in the supine position on a mat or on specialized apparatus, such as the reformer, the cadillac, the ladder barrel, and the high chair. 21 Pilates exercise may improve neu- romuscular efciency (NME), 30 which is commonly measured clinically or during sports activities, and defned as the relationship between the electrical activity and force of the muscles. 31 NME may vary according to gender, pathology, and training, conditions that can afect an individual’s neuro- muscular adaptation. 32-37 Te multifdus (MU) and internal oblique (IO) muscles, acting in co- contraction, stabilize the trunk and control the segmental movement of the spine, keeping it in a neutral posi- tion. 38-39 No studies have been found that investigate NME of the MU and IO in Pilates practitioners who are ballet dancers. Terefore, the aim of this study was to evaluate the NME of these core muscles through electromy- ography (EMG) analysis and a torque test, both of which were applied to a classical ballerina before and after a Pilates exercise intervention. Methods Our study involved one healthy 24-year-old amateur classical ballerina (50 kg, 1.66 meters, and 12 years of practice). Te dancer had no previous experience with Pilates. During the study (8 weeks) she was engaged in no physical activities other than ballet, to which she dedicated 12 hours a week. Te Pilates training sessions and tests were carried out before she em- barked on a dance tour, on alternate hours with her regular ballet classes. All experimental procedures were conducted at the biomechanics labo- ratory in the department of physical education at São Paulo State Univer- Efect of Pilates Mat Exercises on Neuromuscular Efciency of the Multifdus and Internal Oblique Muscles in a Healthy Ballerina Ana C. Panhan, MSc, Mauro Gonçalves, PT, PhD, Giovana D. Eltz, PhD, Marina M. Villalba, Adalgiso C. Cardozo, PT, PhD, and Fausto Bérzin, PT, PhD