Turn On Your Turn Out
As most dancers and dance students wish for a greater turnout, I may have captured your attention with this headline. You may have hoped to find the Secret of Turnout revealed here. That depends on how you look at it. Often a secret is a deep understanding of something rather than being given a magic formula. Therefore, lets look at two anatomical factors that determine the degree of the outward rotation of the leg. One can be altered and the other cannot. The factor you cannot change is the structure of your bones. A deep-shaped and forward facing hip-socket (acetabulum), allows for lesser overall mobility and outward rotation of the thighbone (femur) than a shallow-shaped and sideways facing one.
Visualise this by making a fist with your right hand and cup it tightly with your left. Your right forearm and fist represent your thighbone with its femoral head (top of thighbone) and your left hand represents your hip socket (see fig. 1). You can probably move your right arm forward and backward quite easily but that is about it. Now gradually loosen the grip. The more you open your left fingers ("shallowing" the hip-socket) the more space for multi-dimensional movement you get, including rotational one. But be careful what you wish for. Greater mobility reduces stability and requires diligent strengthening exercises to counteract the imbalance.
Years 5 and 6, State Ballet School Berlin 1989
This brings us to the second factor, the muscular structure and function. You have many muscles of varying sizes attached to your pelvis and thighbone. A very important one for dancers to know is the piriformis. The piriformis is a V-shaped muscle that attaches with its thin end to the side of your thighbone and with its broad end to your sacrum at the base of your spine. By improving its functionality, that is creating well-balanced strength and flexibility; you can increase the degree of your turnout to the healthy optimum for your body. A "worked" turnout supports you during many complex movements; unlike a turnout that relies solely on genetically given flexibility, or worse laxity.
The idea of a perfect 180 degree rotation is such a big deal in classical ballet that once, when we were 15/16 years old in ballet school, the girl next to me at the barre asked whether I would do her a favour and turn out a bit less during the exam we were about to take so her limited en dehors would be less obvious. I replied I may consider it if she would lift her legs less high, something I struggled with. Needless to say neither of us gave up any of our precious "gifts".