Effects Of High Heels On Gastrocnemius Stiffness In Women

BACKGROUND: The effects of an acute bout of high heel wear on the mechanical properties of lower leg musculature has not been shown. Therefore, the purpose of this study is to use ultrasound elastography (SWE) to examine changes in shear modulus of the gastrocnemius (GS) muscles following a simulated workday in high heels. Because the plantar flexors are held in a shortened position it was hypothesized that stiffness of the GS would increase after a day of high-heel wear. We hope to further inform the public on the effects of high-heel wear. METHODS: 22 women aged 25.5 ± 6.6 yrs. in good health, were split between experimental (n = 11) and control groups. SWE images were taken of the medial and lateral GS in anatomical neutral with the participants lying prone on a plinth. Participants in the experimental group wore 3-inch heels provided by the experimenter, the control group wore their own athletic sneakers without a raised heel. To simulate eight-hour workday participants were given a desk and asked to sit with feet planted. Seat height was adjusted to place the hip and knee at 90° of flexion. Every two hours participants completed a short walking task either retrieving multiple objects at the end of a hallway or descending and ascending six flights of stairs. SWE images were taken at the same imaging positions at the end of the day. A mixed model ANOVA was performed to evaluate the effects of group and time on shear modulus of the GS muscles. RESULTS: The ANOVA revealed significant effects for group*time for each muscle. Post hoc t-tests were conducted to illuminate the factors of group and time. Stiffness of the GS increased with high heel wear in the experimental group. GS stiffness increased from 12.6 to 17.5 kPa (t(43) = 9.93,p = 3.3E-12). No significant differences were found between groups before the intervention (t(43) = 0.71,p = 0.24). No significant changes in GS stiffness were seen in the control group. CONCLUSION: An eight-hour workday of wearing high heels correlates to significant increases in GS stiffness. There were conversely no significant increases in stiffness in the control who completed the same intervention while wearing sneakers.