The symmetrical indentations that sometimes appear on the lower back are commonly referred to as “back dimples” or, formally, fossae lumbales laterales. These aesthetic features are also informally known as the “Dimples of Venus.” Understanding the physical mechanism that creates these indentations is key to determining whether they can be acquired or simply made more visible.
The Anatomical Origin
These indentations are always situated on the lower back, directly over the pair of sacroiliac joints, which is where the sacrum connects to the ilium of the pelvis. The physical mechanism that creates the dimples involves a short, specialized band of tissue. This tissue acts as a tether, connecting the skin directly to the underlying pelvic bone.
Specifically, this short ligament stretches from the skin to the posterior superior iliac spine (PSIS), a bony prominence on the pelvis. This firm connection pulls the skin inward at that location, creating the characteristic depression. The dimples are formed by this ligamentous attachment to bone, not by muscle tissue or a lack of fat, meaning they cannot be “toned” into existence.
Why Genetics Determine Their Presence
The presence of the unique, short ligament required to form a back dimple is a congenital feature. This anatomical structure is determined by an individual’s genetic inheritance. If the genetic blueprint for this specific ligamentous connection between the skin and the posterior superior iliac spine is not present, the dimples will not form.
Since the anatomical structure is genetically predetermined, exercise, stretching, or weight loss cannot physically create the dimples if the underlying structure is missing. The trait is widely believed to follow an inherited pattern, often described as an autosomal dominant trait. This suggests that inheriting even one copy of the responsible gene may be sufficient for the structure to be present. For those who lack the inherited anatomical anchor, acquisition is impossible.
Strategies for Visibility
For individuals who have inherited the necessary anatomy, the visibility of their back dimples is largely dependent on the amount of subcutaneous fat in the lower back region. A layer of fat over the area can obscure the indentation, making the dimples difficult or impossible to see. Therefore, the most effective strategy for enhancement is to reduce overall body fat.
Achieving a lower, healthy body fat percentage allows the skin to sit closer to the pelvic bone, thereby revealing the indentation created by the short ligament. For women, an athletic body fat range of approximately 14% to 20% is often cited as a range where existing dimples may become prominent, while for men, this range is typically 6% to 13%.
Targeted strength training focused on the lower back and surrounding gluteal muscles can also improve the appearance of existing dimples. Building muscle tone and definition in the region can tighten the area and further accentuate the depression. Movements such as deadlifts, the Superman exercise, and glute-focused bridges or hip thrusters are often recommended for this aesthetic enhancement.