The most common medical complaint from groomers and kennel operators
is an aching back.
  The fact of the matter is that men and women have been experiencing back
problems in one form or another ever since our ancestors first assumed an
upright position. The reason is simple. Our lower back bears the brunt of our
body's weight.
  The majority of lower back discomforts are described as "simple" back
pains, which means that the damage is minor and repairable. The usual
causes include overexertion, tension and stress, excess weight, emotional
problems and/or normal aging.
  However, if you ignore persisting pain without seeking professional medical
care, minor back problems can (and probably will) become chronic.
 
                                               A NORMAL BACK

  Your lower back (lumbar area) is composed of a series of vertebrae,
associated discs, nerve roots, muscles and ligaments.  The largest discs
are found in the lower back, and these bear the heaviest load.
 
Figure 1  "The Vertebra"

  A normal, healthy back in straight, strong, flexible and virtually pain free.
Its chief functions are to support your upper body and protect your spinal
cord, while allowing maximum flexibility.
  That complex computer, the brain, sorts out the nerve impulses that are
sent up the spinal cord from the nerve endings in the spine. Signals of pain
translate into muscle spasms, intended to keep you immobile while the
damage heals.