At a postural level, many doctors, physiotherapists and chiropractors are convinced that lower back pain induced by heels is due to an increase in lumbar lordosis associated with an anterior pelvic tilt; this thought is even shared by the American Chiropractic Association and the American Physical Therapy Association. Furthermore, in most of the websites consulted, even by non-experts, the reason for the onset of spinal pain is attributed to hyperlordosis and pelvic anteversion. However, this thought is not entirely in agreement with other scientific publications. Therefore it is necessary to pay attention to online searches which often answer these questions without taking EBM into account. None of the studies reported above take into consideration the time factor. In fact, all the studies have evaluated the immediate changes brought about by heel raising. Women who complain of lower back pain when wearing high-heeled shoes rarely experience pain as soon as they start wearing them. The objective of the research arises from these considerations. The aim of this study (primary outcome) is to investigate whether wearing high-heeled shoes for at least 2 hours modifies the spinopelvic parameters compared to the barefoot condition and as soon as the shoes are worn. The secondary outcome will be to verify in the sample analyzed whether there are different behaviors between the subgroups of those who have complained in their anamnesis and those who have never complained of lower back pain when using high-heeled shoes for a few hours.