I put this video up on my facebook page the other day as a stunning display of skills. Watching it over and over again it is also a stunning display of alignment. As a walking and yoga teacher I basically spend my time looking at the wrinkles people make in their clothing as they walk and stand. You can tell so much by the wrinkles or lack of wrinkles that posture and movement create in what we wear. The video shows a Cara Black volley practice drill, against a wall. Cara Black is a professional tennis player from Zimbabwe, currently ranked #1 in the world in doubles.
In yoga there is an important concept known as shoulders on the back which illustrates how the shoulder blades are designed to move and work. In an ideal world a series of muscle all engage to keep the shoulder blade in a fairly neutral position shimmying this way and that with each action. Unfortunately in most people, you will find muscular imbalances that allow the shoulder blade to move too much one way or the other.
When you watch the video you can see a shallow groove between the two shoulder blades that never goes away. With hit after hit her arms stay in their sockets, the shoulders stay on the back each stroke comes from the deep core. In yoga I hope to see that small groove in all variations of poses, especially planks.
Another set of wrinkles to watch is in the lower spine. Her lower back is slightly curved and the rotation of the spine is clearly seen in the twisting wrinkles at the lower back. And the wrinkles at the lower and upper back are beautifully coordinated. I look for this wrinkle pattern in the lower back as people walk. Every step is supposed to be a spinal twist that you can witness in the movement of a shirt.