Summary:
Introduction: Breast augmentation, regardless of whether is inherent or is acquired following a surgical procedure for aesthetic purposes, may affect the functional ability of the trunk and neck musculature which in turn may result in a number of functional limitations in performance of both daily and sporting activities (Cerrato et al, 2012; Chadbourne et al, 2001; Findikcioglu et al, 2007; Spector et al, 2008) . The aim of this study was to estimate the effct of experimentally-induced breast augmentation on the functional ability of the trunk muscles.
Methods: The electromyographical (EMG) activity of sternocleidomastoid (SCM), upper trapezius (AT) and erector spinae muscles at thoracic and lumbar levels (EST, ESL) was measured during trunk flexion at 45ᵒ from the standing and sitting position (TF45ᵒST, TF45ᵒSI), standing to sitting (STSI) and shoulder flexion 180ᵒ from the standing position (SF180ᵒST), as well as in the upright position of the trunk before the beggining of these movements, in 24 young healthy women with natural breasts as well as with breast size which was increased by three and six times.
Results: Breast size was increased by usining external silicone inserts with volume/mass ratio equal to one. The findings of this study showed significantly greater EMG activity for LES and TES just before TF45ᵒST and TF45ᵒSI, as well as during execution of the aforementioned movements, and for UT during execution of STSI and SF180ᵒST but only when breast size was increased six times.
Discussion-Conclusion: The increased EMG activity that was obtained was probably attributed to a greater amount of activity that was necessitated for compensating the resulting increased flexion moment. The increased flexion moment was produced by the greater load and the longer moment arm that was generated by the bulkier silicon-gel implants that were added in the front aspect of the chest.
Keywords:
EMG activity, trunk muscles, breast augmentation, erector spinae, sternocleidomastoid, upper trapezius
