T) Análise da relação entre dor lombar e desequilíbrio de força muscular em bailarinas (I) Analysis of the relationship between low back pain and muscle strength imbalance in ballet dancers

Abstract Objective: To investigate the relationship between low back pain and muscle strength imbalance in the lumbopel-vic region of classical ballet dancers. Methods: This cross-sectional exploratory study was developed in the ballet academies of Divinopolis and Oliveira, Minas Gerais State. Forty-two ballet dancers were selected and then divided into two groups (Pain and Painless Groups), according to the presence or absence of pain complaints in the low back. Firstly, the ballet dancers were submitted, by one examiner, to four tests of muscle strength imbalance in the lumbopelvic region: gluteus maximus × hamstrings muscles and gluteus maximus × paraspinal muscles in the hip extension movement; gluteus maximus and medius × tensor fascia latae muscles in the hip abduction movement; abdominal × hip flexors in the hip flexion movement. After that, a second examiner applied the muscular strength tests for the abdominal and paraspinal muscles. Chi-square tests were used to verify the association between low back pain and muscle imbalances. The level of significance was set at α = 0.05. Results: Most of the ballet dancers, independently of the group, showed muscle strength imbalances in the lumbopelvic region. The abdominal × hip flexors test demonstrated a significant association with low back pain (p = 0.043). Conclusions: Muscle imbal-ances in the lumbopelvic region are common in classical ballet dancers. However, it is not possible to assure that these muscle imbalances are specific adaptations to the classical ballet or dysfunctions associated to algic symptoms resulted from training faults.[K]Keywords: Classical ballet. Muscle imbalance. Low back pain. Physical therapy.