Happy Hips for Horse & Rider

Today we venture back in horses and down in humans, into territory that many believe to be the foundation of the skeletal system and the body itself: the pelvis. It is an area of much more complexity than many realize, an area that impacts, quite literally, every other part of the body. It contains and protects some rather important things, namely the urogenital system, and provides stability to many others. And in horses and riders, pelvic happiness is critical for success in the saddle. 

First, put your geek hat on. We need to understand the mechanism of the pelvis to get a sense of what we need to do to support its mobility. The innominate bone is actually three separate bones at birth – the pubis, ischium, and ilium – which eventually fuse together, completing at as old as 17 years in humans. (In horses, the pelvis is still growing and fusing at age four, just one more reason to let our babies grow up before we start asking more of their bodies.) The meeting point of these three bones is the acetabulum, a concave surface which doubles as the articulating surface for the femoral head. This is the ball-in-socket coxofemoral joint, most commonly known as the hip joint. The meeting of the two pubic bones is called the pubic symphysis and for riders, the mobility of this region is paramount to your comfort, especially at the seated trot. And on the other end of things, the ilium of the pelvis and the sacrum (the flat bone at the base of your spine) meet to form the two sacro-iliac joints, attaching the vertebral column to the pelvis and the rest of the body (see Figure 1). Many riders are quite familiar with one or both of these joints in ourselves, because they are common areas of discomfort. Not surprisingly, the same is true for our horses

Given our verticality, our pelvis is shaped rather differently than that of our horse, but the principles are very similar. In health, the sacrum dissociates from and moves freely between the ilia, the three bones of the pelvis have fused well and have rebound, and the femoral head moves easily (but not too easily) in the acetabulum. As one can imagine, this is not commonly the case, especially when you add ligaments, muscles, fascia and dura to the mix, as well as take into