Undulations Painted/Draped on Sidebent Spinal Curves: Transverse, Longitudinal and Torsional Waves

Lalu Simcik


    Transverse waves are those we see in a jump rope
    lying on the ground right after the rope end is
    abruptly flicked.  The wave packet travels like a
    train on its tracks down the length of the rope.  
    When shaking sheets out onto a bed, we also create
    transverse waves that move the sheet away from our
    hands and spread it out more evenly.
    Longitudinal waves can be listened to whenever a
    train leaves the station.  The engine car pulls
    away first, and then each loose car gets pulled in
    sequence, creating an audible pulse that travels
    down the entire length of the train.
    Torsional waves are sequential twists that travel
    down the length of our spine or a long flexible
    object.  When we are standing and rapidly turn our
    head around its vertical axis to one side, we
    create a torsional wave that descends down the
    body.  The head twists the neck and connecting
    muscles while sending a wave of torsion (twist)
    that can be soon felt by the torso as it follows
    the head.  Immediately after this, the same wave
    can be felt as the pelvis follows the torso in the
    original direction of twist.

    A stiff body does not allow this sequential wave
    action to occur, rather, the twist will be replaced
    by a solid rotation of the entire body as it moves
    as one piece.  Although this motion may be desired as an end
    result of the torso, pelvis, and legs during a
    pirouette, most ballet dancers spot their
    eyes by having the head lead the torso and then the
    torso lead the head.  Using torsional waves in
    between the head and torso, rotational undulations
    rotate the cranium ahead of the torso's rotation,
    then stop it at the spot point.  After the torso
    passes, it's energy rotates the cranium once again
    to pass ahead of the torso onward to the next spot.  
    The viewer is mesmerized by seeing a body in full
    dynamic motion, yet the dancers face appears
    held in stillness.  Even though the torso and
    pelvis rotate together, an efficient entry,
    maintenance, and exit from a pirouette requires a
    spine that is available for undulation.
    Transverse, longitudinal and torsional waves of
    kinetic energy travel the length of our spine,
    leading and guiding our extremities.  
    Alternatively, motions of the extremities can
    distally motor the neck, torso, or pelvis, to
    create transverse, longitudinal and torsional waves
    of energy that travel back through the spine.
     Flattening or reversing any of the three spinal
    curves reduces, impedes, or inhibits the ability of
    the spine to transmit these waves.  Vertebrae get
    stuck at their natural stops and cannot rotate.  

    Flattening or reversing spinal curves is metaphoric
    to adding starch to a section of our jump rope, and
    then trying to pass a wave through a rope that
    won't take on the shape of the wave.
     Sidebending maintains spinal curves which are
    necessary for healthy wave propagation.
    In slow movement, undulations are most visible in
    the lead and lag of body parts or in the sequence
    of moving vertebrae.  In higher dynamic movement,
    increased necessary tensions reduce the size
    (amplitude) of the undulation.  The increased
    tension causes the wave to travel much faster
    through the body making the wave less visible to an
    observer. Since the waves travel the same distance
    up or down the spine as low dynamic undulations,
    the fast moving high dynamic undulations are
    visible to the eye for a much shorter period of
    time.  Our common sense of "seeing is believing"
    leads us to falsely conclude that undulations
    disappear entirely during high dynamic movement.   
    Can a guitar string be heard long after our eyes
    say it is still?  This phenomenon is most notable
    on the thinnest strings held with the highest

    A body that allows undulation can move with high
    dynamic efficiently, conserving energy by recycling
    waves in 'body echos'  or reflections.  
    Alternatively, undulations can be directed to raise
    any motor-ic mass or the body in its entirety.  
    This transforms the kinetic energy of motion in the
    wave into the potential energy stored in a risen
    body.  Increased tension levels in muscle groups
    surrounding spine create the
    metaphoric guitar string which can be tuned for fast
    moving high energy waves with small amplitudes and
    brief transit times.  The paradox is that energy
    waves become almost invisible to the human eye as the
    energy of the wave packet increases, while have no waves
    at all transmits zero energy along the spine.  

    The perceivable difference is that a no-wave-dancer generates
    new movement without recycling or being informed by 'old
    kinetic energy,'  while the wave-dancer recycles and directs
    the previously generated 'old kinetic energy.'
    Any part of the body that has risen from harnessing
    a wave can then fall again.  This falling can be
    used to create new motion in that can be
    transmitted further to other parts of the body.   
    And so the never ending story of movement
    continues, until we choose stillness or our
    energies randomly scatter.

    Let us briefly consider the less ideal situation
    when a body moves dynamically with excess tension
    in the neck, torso, and abdomen.  The body will
    move more like one giant block, without any
    springiness.  This type of movement will require
    the legs and arms to push every time the body
    rises, and push every time the body falls, as
    momentum and energy are inefficiently conserved.  

    This is a body whose undulations have disappeared.  
    This is a dancer who is working too hard.  
    The highly energetic transverse waves that travel
    on the ocean, known as a tsunamis, can contain
    energy far exceeding any wave caused by even the
    greatest of hurricanes.  Tsunamis travel the ocean
    at approximately 600 miles per hour  (970 km per
    hour) which is the same speed as airliners.   When
    they pass large ships or small craft on the open
    ocean, there is typically a six inch (15 cm) rise
    in the water level that is spread out over many
    kilometers.  People on board often don't know that
    a powerful wave has just passed.  Only when the
    wave reaches shallow water does the land direct all
    the kinetic energy into a tall rising of the water
    just offshore.  When the water can no longer
    support itself, it falls forward and spills out
    onto the land as a river of ocean water.  All the
    movement and aftermath of a tsunami comes from a
    barely visible high speed wave.  A similar
    phenomenon occurs in and around our spine.  


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