Many of the stances in taiji seem awkward at first. The body needs to be reprogrammed to stand, to walk, to be still, to move. Didn't we all learn to walk when we were toddlers? Yes, we did, but we picked up all kinds of bad habits. Taiji helps us consciously learn better habits.
Master Jesse Tsao spekas of an "energy channel" to be kept between the feet when walking forward or backward. This means that moving from wuji stance (feet shoulder width apart) to bow stance (one foot ahead of the other, weighted toward the front foot) feet should still be about a shoulder width apart. Effectively this means as you step forward you also step to the side. It is counter-intuitive as we are used to walking forward with a very narrow stance. If you begin with your feet more or less together, you tend to walk forward with a short sideways distance between your feet. In taiji the stance is more open. This distance between your feet is the energy channel. With practice it becomes more "natural" and is a much more balanced stance. I have noticed with students that it takes quite a time to retrain the body and open the stance. The temptation is always to narrow the stance (side to side). It helps to spend dedicated time simply walking forward and backward, focussing on the sideways distance between the feet.
Here is a great article on the bow stance from Neigong.net