J Back Musculoskelet Rehabil. 2021;34(3):371-380. doi: 10.3233/BMR-200090.
Chest size is a known factor in the development of back pain for women. However, the neuromuscular mechanisms associated with chest size and back pain are poorly understood.
The purpose of this study was to investigate chest size and its association with back pain development and muscle activity patterns during prolonged standing.
Twenty university-aged women were divided into two groups: small chest size (n= 10, ∼A/C cup) and large chest size (n= 10, ∼D/E cup). Participants completed a 2-hr standing protocol, where eight channels of bilateral trunk electromyography were collected. Muscle activity, specifically co-contraction, was compared between chest size groups, pain developers, and time.
The large chest size group reported higher amounts of pain at the upper, middle, and low back. Women in the large chest group sustained higher levels of co-contraction for muscles involving the thoracic and lumbar erector spinae compared to those in the small chest size group during prolonged standing.
Thoracolumbar co-contraction determined in this study may be a potential mechanism contributing to increased back pain development for women with large chest sizes during prolonged standing. This pain mechanism could be targeted and addressed in future non-invasive musculoskeletal rehabilitation to improve back pain for women.
胸部大小是女性背痛发展的已知因素。然而，与胸部大小和背痛相关的神经肌肉机制还知之甚少。
本研究旨在探讨胸部大小及其与腰痛发展以及长时间站立时肌肉活动模式的关系。
20 名大学年龄的女性被分为两组：小胸组（n=10，A/C 罩杯）和大胸组（n=10，D/E 罩杯）。参与者完成了 2 小时的站立协议，其中采集了双侧躯干 8 通道肌电图。在胸部大小组、疼痛发展者和时间之间比较了肌肉活动，特别是协同收缩。
大胸组报告上背部、中背部和下背部疼痛程度更高。与小胸组相比，大胸组在长时间站立时，参与胸腰椎竖脊肌的肌肉协同收缩水平更高。
本研究中确定的胸腰椎协同收缩可能是大胸女性在长时间站立时背痛发展的潜在机制。未来非侵入性肌肉骨骼康复可以针对这种疼痛机制，以改善女性的背痛。
