Postural influence of high heels among healthy adult women.

This research is a cross-sectional study comparing the trunk muscles electromiographic (EMG) activation pattern between females who often used high heels and who only used high heels sporadically. Subjects will be reported to the Laboratory for a single testing session. After cleaning the skin with isopropyl alcohol, active surface EMG recording electrodes (Ag/Ag Cl) will placed on trunk and abdominals muscle, at standardized sites on the dominant leg, determined as the one with which they would kick a ball. A ground electrode will attached to distal tibial region . All electrodes will taped to the skin to reduce movement artifacts and remained in place throughout the study. EMG signals will sampled by a 12-bit A/D converter board with a 4 kHz frequency, and band-pass filtered at 0.01–1.5 kHz. Raw EMG data were digitally filtered at frequency bandwidth of 20–500 Hz and the root mean square (RMS) was calculated. The subjects were photographed in the sagittal plane. First, they wore a two-piece swimsuit and no shoes, tennis and high-heeled shoes for the subsequent postural evaluation. A few anatomical points were marked out, including the occipital protuberance, C4, C7, T7, T12, L3 and L5 spinous processes, greater trochanter, anterosuperior iliac spine (ASIS), posteroinferior iliac spine (PIIS), tibial tuberosity (TT), head of the fibula, lateral malleolus, and head of the 5th toe. These markings were made with white 0.9mm-diameter PIMACO labels and orange-colored plastic rods held in place with double-sided tape. The images were analyzed with the application SAPO (postural analysis software) version through measures of the angles formed by lines drawn between the previously marked anatomical points. This analysis identified and quantified possible asymmetries and vertebral curvature angles. The duration of study will be of 6 months. The approximate duration of the single testing session was 60-90 minutes (20 minutes with no shoes, 20 minutes with tennis shoes and 20 minutes with high-heeled shoes).The first 20 minutes involved performing a physical evaluation.