03/17/2021
This brief video shares my understanding and experience of this commonly cued yoga instruction, "ground the femurs" or "taking the top thighbones back". You may have also heard the following terms: inner spiral your thighs, expanding spiral, moving your sitting bones back and apart, roll your inner thighs back, deepen your groins. From my experience, each of these cues is in a similar family albeit some may be more subtle and 3-dimensionally integrate structures distally and proximally, i.e. Inner Spiral of the Anusara style of yoga. However intricate and subtle the aforementioned instructions may be, it is to my understanding "grounding the femurs" is positioning the spherical head of the femur into the deeper aspect of the acetabulum. We want the femurs to be deeply sheltered in the cave of the hip socket. Let's pause for a moment to explore the basic landscape of joint geography. Bones and joints are classified by their shape and structure. Structure and function are inextricably woven throughout the tapestry of the body. Is it the function that determines structure? Or, the structure that determines function? It's a bit of the "chicken before the egg" koan. Before I continue upon this philosophical exploration, let me revert the bones of this description. The iliofemoral joint is classified as a "ball-and-socket" joint. The structure and shape of a joint determine its range of motion. We can also argue that unseen patterns of function ranging from movement, genetics, etc, determine the structure within a gravitational field and for biological and evolutionary purposes. The head of the femur is a sphere and the acetabulum is a socket. Joints are comprised of two bones coming together. To a greater or lesser degree, one end of the bone is more concave, the other is more convex. In the example of the iliofemoral joint, the femur is the convexity, and the acetabulum is the concavity. We want the femur (convexity) to be deeply sheltered in the concavity of the acetabulum, especially in a weight bearing position like Mountain Pose.
