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1.
Based upon our interpretation of the JAP 2000 findings, an interpretation which
has met with the approval of the researchers, we believe that applying
mass-specific ground force is the mechanism athletes use to take longer strides.
Charlie Francis noted the following in his latest manual: “Too many coaches are
coaching the speed right out of their athletes. Some believe that it is stride
frequency and others believe that it is stride length that causes speed. The
answer is neither. They are both measurements of speed but not the cause of
speed. Speed is the result of net forces acting on the ground.”
2. Sprinting comes
down to large mass-specific forces applied during brief foot-ground contact
times. Charlie Francis has said basically the same thing: “One of the main
effects of sprint training is to allow sprinter to achieve the maximum force on
the ground in the shortest time possible.”
3. Body and limb movement during
constant-speed level running is performed largely passively by tendons and
energy transfers. Isolated drills to improve form are more likely to worsen than
improve the economy of running. Dr. Mike Young has noted the following in this
regard: “Sprint drills do not in and of themselves develop proper sprint
mechanics and may in fact be detrimental. Sprint drills can however provide an
opportunity to teach cues that can be used in full speed sprinting, or create
desired sensations which may carry over to full speed sprinting. These benefits
however are contingent on the manner in which the sprint drills are performed.
Sprint drills may also be used to develop certain physical capacities or warmup
the athlete.”
4.
Delicate proportionality between the runners mass and ground force demands a
method of training that produces superior strength with minimal increase in mass
Biomechanist Dan Andrews recently said the following: The role of mass and
particularly that caused by hypertrophy has changed or needs to be reviewed in
the context of the structure of the individual as a result of training and not
to be training for added mass. Frans Bosch said the following at an ’07
symposium here in Illinois: “stop doing hypertrophical training and you’ll be a
much better athlete.”
5. Volitional attempts to alter force on
the ground or improve swing mechanics via such techniques as dorsiflexion or
pawback are not means supported by locomotion research or the physics of a
falling body. Vern Gambetta has gone on record offering his comments on
dorsiflexion and the pawback: “Personally this was a vindication because I feel
like I have been a voice crying out in the dark on this one. Take home point on
this one: forget cueing all the stuff on dorsiflexion. The other one was in
regard this idea of pawing. It does not occur; you can’t do it, so forget it.”
6.
Once a runner is up to speed there is little to no mechanical work or forward
propulsion required. Runners bounce along the ground like rubber balls
maintaining their forward momentum as they bounce up off the surface during each
contact period. Corroboration for the spring mass model goes back over forty
years: all running animals, from small insects to large mammals, exhibit a
center-of-mass motion that resembles a bouncing ball or a pogo stick
7. Push off in the classical sense of active
plantar flexion (force at toe-off) occurs in the latter third of stance phase
when forces are minimal. Considering this, active push-off (muscle shortening)
is not a means by which athletes apply greater force to the ground. Research by
Giovanni Cavagna and Dick Taylor, published in the 1960s, 70s, and 80s,
suggested that there is little to no requirements for mechanical work and
forward propulsion once a runner gets up to speed
8. Arm swing is often unique to the
attachment points, lengths, and hard-wiring of each athlete, and arms in general
perform like passive pendulums, providing balance and minimizing center of mass
energy losses. Arm swing does not control leg movement, and the amplitude or
direction of arm swing is not a contributor of force on the ground. Dr. Ralph
Mann drew these conclusions in the 1980’s. "I will emphasize once more," noted
Dr. Mann, "that the hands and arms are not significant contributors to
improvement in sprint performance."
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