Yes of course. The practice of Yoga does confer a certain flexibility with time but it is not a goal in itself. The objective of yoga postures is really about bringing balance to the various systems in our organism. This is done by putting the body in a certain position that will stimulate and harmonize specific groups of muscles and organs. Everyone is working at his own level, with eyes closed, and there is no spirit of competition or performance. To obtain the benefits of a posture, all is required is to place the body properly, to focus on the breath and relax. That’s all. So everybody is receiving the same benefits out of a posture, regardless of the level of flexibility or strength. Someone more flexible will simply have to go further in the posture to get the benefits.