Not a twinge, exactly. More a weight. A disturbance in the flesh. I feel it as I stretch my arms above my head at the beginning of surya namaskar and again in vriksana. The sole of my foot presses against the mat and the toes are spread, firm but not clenching. I breathe and feel my muscles respond, loosen. The first class of the day brings the energy of the sun and these familiar poses balance and awaken and empower. The air is still bracing; these old heaters take some time. The class is lined up before me, concentrating. They have not noticed anything amiss. They are following my movements, my instructions for each pose, but I do not feel balanced. There is something here that is not right. ‘Draw the flesh of the right inner thigh outward,’ I say. ‘Engage the thigh muscle. Engage the knee. Pull the skin on the inside of the left leg towards the back of the room.’ Some in the class are fluid and some are not. My heart goes out to the stiff ones, the way they try week after week, struggling with something that does not come easily.