Place a stick over your spine and press it to it using both arms. Now start moving the stick using your spine and see in how many directions and ways you can do this. Note how this affects your limbs and head and work so your breath leads the movement.
To relax sit on your shins and place the stick on the back of the shins. Press it through the tension using your arms and breathe to let the tension clean out and move the pressure around so you make your legs more free rather than soft. Remember it is not relaxation but awareness and control of tension. No tension at all means death.
The Martial Art of Walking 