Announcement

Collapse
No announcement yet.

POPULARISED BIOMECHANICS

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • POPULARISED BIOMECHANICS

    Recently an article "Toward an Understanding of Power" was written in the
    NSCA's Strength & Conditioning Journal (Oct 1999: 34-35), which contained
    some curious biomechanical definitions and calculations. Here are a few of
    them for your interest:

    1. "For instance, in cleaning a weight, the velocity of the bar is equal to
    its speed and the upward direction in which it moves."

    2. "Strength times speed equals power"

    3. Work = force x distance, where Force = Mass lifted,
    Distance = gravity x height of pull
    Gravity = 9.8 m per sec squared

    The article then used the above definitions to calculate power and hence
    compare the power generated in the Weightlifting clean and the Powerlifting
    deadlift, thus:

    Power = Work/Time to execute lift

    ...but did not distinguish at all between mean power, power at any instant
    and peak power during the lifts concerned (deadlifts and cleans).

    Would anyone else care to comment on the material which I have quoted above?

    In a letter to the editor of the journal, I stressed that one cannot casually
    equate the vector, velocity, and the scalar, speed, especially in non-linear
    dynamic lifts and that work is not simply force x distance in a system in
    which force and direction of application of the force is changing throughout
    the movement. I also pointed out the obvious errors in equating force with
    mass and in defining Distance = gravity x height of pull.

    The author of the article simply replied in the Aug 2000 issue of the same
    Journal that:

    " I had Dr L, chairman of the math/physics department at ........ University,
    review the formula along with the comments. Dr L said that my calculations
    are correct...... In trying to make the formula more understandable to
    people with no background in math and physics, I had added a few extra words
    for clarification purposes, which to a purist was not acceptable."

    Would anyone care to comment on this response, as well?

    What concerns me is that this NSCA (National Strength & Conditioning
    Association) publication reaches tens of thousands of its members all around
    the world, many of whom do have at least 4 year degrees in physical
    education, kinesiology, science, physical therapy and related fields. The
    NSCA administrates and awards the CSCS (Certified Strength and Conditioning
    Specialist) qualification and Personal Trainer certification. It is widely
    regarded as the definitive source of strength training information for
    strength coaches and includes many highly qualified scientists in its ranks,
    yet it seems quite contented to allow seriously misinterpreted scientific
    information to reach its members.

    The NSCA is not unique in this regard. Many other certifying bodies and
    training organisations in the strength and fitness realm reveal a similar
    attitude that their members "are not scientists" and need not be given a
    rigorous background to the simplified concepts that are taught to them.
    While popularisation of difficult concepts is vital for the general public
    and some folk such as the late Carl Sagan were masters at this, are these
    organisations not doing their members and the strength/fitness professions a
    grave disservice? Is there any solution to this problem?

    Dr Mel C Siff
    Denver, USA
    http://www.egroups.com/group/supertraining

    ---------------------------------------------------------------
    To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
    For information and archives: http://isb.ri.ccf.org/biomch-l
    ---------------------------------------------------------------
Working...
X