Are All Yoga Sutras Spiritual in Nature?

The Yoga Sutras of Patanjali include many sutras that are not directly related to enlightenment or self-realization but can accelerate the process and eliminate a large number of obstacles.  These sutras help us understand our mind and thought processes; how the worlds inside and outside us relate to each other; and how to avoid obstacles and troubles both known and unknown to us.  Some sutras describe special powers, but the Yoga Sutras cautions us that these powers themselves tend to be obstacles to enlightenment.