Spinal curvature and trunk muscle tone in rhythmic gymnasts and untrained girls

Abstract

The aim of this study was to compare spinal curvature and muscle tone characteristics in elite female rhythmic gymnasts (n = 32) and untrained controls (n = 48). Results showed that the angles of lumbar lordosis (LL) and thoracic kyphosis (TK) were lower (p < 0.001) in gymnasts in comparison with the control group. It was evident that the vertebral column of gymnasts had straightened in thoracic as well as in lumbar part of the spine. The trunk flexors in gymnasts were undertoned, the tone of rectus abdominis muscle was lower (p < 0.001) in gymnasts compared to that of the control group, while tone of erector spinae muscle (trunk extensor) was not differed from the control group. The tone of spinal muscles was higher (p < 0.001) than that of abdominal muscles in gymnasts, whereas the tone of these muscles did not differ significantly in controls. In the control group, the tone of trunk flexor and extensor muscles were in balance, whereas in gymnasts it was imbalanced. The indicator of tone imbalance of the trunk flexor and extensor muscles correlated negatively with the difference in body height in supine and standing positions (L) (r = −0.66, p < 0.001) for the group of gymnasts. In gymnast, TK and LL correlated negatively with Oswestry score (r = −0.68, p < 0.05 and r = −0.66, p < 0.05, respectively) and positively with L (r = 0.63, p < 0.05 and r = 0.60, p < 0.05 respectively). This indicates that the more rigid vertebral column, flattened in thoracal and lumbar part that appeared in gymnasts, associated with imbalance in muscle tone and low back pain (LBP). In 50% of measured gymnasts, LBP incidence