Kateina Christina, Mandalidis Dimitris
Sports Physical Therapy Laboratory, Department of Physical Education and Sports Science, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece.
J Funct Morphol Kinesiol. 2022 Oct 3;7(4):80. doi: 10.3390/jfmk7040080.
A female breast can be a potential source of musculoskeletal problems, especially if it is disproportionately large. The purpose of the present study was to examine the effect of artificially induced breast volume on the EMG activity of neck and trunk musculature during common everyday movements. The EMG activity of the sternocleidomastoid (SCM), the upper trapezius (UT), and the thoracic and lumbar erector spinae (TES, LES) were recorded during 45° trunk inclination from the upright standing and sitting postures (TIST45°, TISI45°) as well as during stand-to-sit and sit-to-stand (STSI, SIST) in 24 healthy females with minimal and ideal breast volume (M-NBV, I-NBV). All movements were performed before and after increasing M-NBV and I-NBV by 1.5-, 3.0-, 4.5-, and 6-times using silicone-gel implants. Significantly higher EMG activity for TES and LES were found at 6.0- and ≥4.5-times increase the I-NBV, respectively, compared to smaller breast volumes during TIST45°. EMG activity of UT was higher, and TES was lower in M-NBV females compared to I-NBV females in all movements but were significantly different only during SIST. The female breast can affect the activity of neck and trunk muscles only when its volume increases above a certain limit, potentially contributing to muscle dysfunction.
女性乳房可能是肌肉骨骼问题的一个潜在源头，尤其是当它过大时。本研究的目的是探究在日常常见动作中，人工诱导的乳房体积变化对颈部和躯干肌肉组织肌电图（EMG）活动的影响。在24名乳房体积最小和理想（最小正常乳房体积、理想正常乳房体积）的健康女性中，记录了胸锁乳突肌（SCM）、上斜方肌（UT）以及胸段和腰段竖脊肌（TES、LES）在从直立站姿和坐姿开始45°躯干倾斜（TIST45°、TISI45°）以及站坐转换和坐站转换（STSI、SIST）过程中的肌电图活动。所有动作均在使用硅胶植入物将最小正常乳房体积和理想正常乳房体积分别增大1.5倍、3.0倍、4.5倍和6倍之前和之后进行。与TIST45°期间较小乳房体积相比，分别在理想正常乳房体积增大6.0倍和≥4.5倍时，发现胸段和腰段竖脊肌的肌电图活动显著更高。在所有动作中，最小正常乳房体积女性的上斜方肌肌电图活动更高，胸段竖脊肌肌电图活动更低，但仅在坐站转换期间差异显著。只有当女性乳房体积增加到一定限度以上时，才会影响颈部和躯干肌肉的活动，这可能会导致肌肉功能障碍。
