In order for the chakras to work smoothly, they need to be aligned with each other. The most direct alignment is with the spine relatively straight. If the spine is too straight, it becomes rigid and tense which blocks the opening of the chakras.
Standing with feet shoulder-width apart, stretch your hands up high over your head, reaching with your whole body, stretching out each of your chakras. Feel how this elongated position encourages the chakras to align.
When you return to a normal standing position, try to maintain that sense of height, aligning your body so that the central core of each major section (pelvis, solar plexus, chest, throat, head) feels in direct alignment with the central axis of your body. Allow your feet to connect solidly below you and feel the central core (sushumna) that connects all the chakras.
Source: Wheels of Life