Your body is designed to move. It is not designed to be slumped at a computer, stuck in traffic or in your reecliner.  Proper spinal movement is defined by flexibility and strength.

Having adequate flexibility around the spine and pelvis allows full spinal movement. This prevents abnormal forces on your joints and decreases the possibility of injury.
    
Stretching  prepares muscles for activity. Stretching before and after a workout can prevent muscles strain, soreness and help to avoid injuries.