Sinusoidal problems

[Guest guest]

Dear Mel and All:

In my research, I have continually come upon issues relating to the

specifics of what is meant by sinusoidal loading or perturbations.

Search as I may I cannot find any specific documents that clarify this

issue to my satisfaction. It does appear that harmonic motion and

oscillators are relevant here but, I still can't seem to put it all

together in real world terms and examples.

Any help with " real world " examples would be greatly appreciated.

[All sinusoidal actions in all situations are ones which are described by

the mathematical sine function Y = sin X, which describes smooth, non-jagged

up and down, or to and fro, oscillations of exactly the same amplitude and

frequency. Since I

cannot draw any pictures here, go to any book or website on basic mathematics

and

see what a sine wave looks like (by the way it has exactly the same shape as a

cos or cosine

wave, though the latter begins from peak not zero amplitude) Mel Siff]

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Mel: in your P & Ps relative to isometrics, you state that:

ISOMETRIC TRAINING

Ref: Siff & Verkhoshansky " Supertraining " 1999, Ch 4.2

Some Web information on the text:

http://www.geocities.com/Colosseum/8682/siff.htm

" This is corroborated by research which showed the maximum tension

that can be produced voluntarily during sinusoidally pulsed brief

isometric jerks at 5 Hz is the same as the maximum sustained tension.

Basmajian (1978) commented that this emphasizes the importance of

muscle fibre recruitment in the gradation of tension and

synchronisation of motor unit activity during the short bursts of loading. "

****The other issue here is how do you measure or know 5Hz, what would

be an example?

[This 5Hz (cycles or waves per second) oscillation was imposed by a vibrating

motor, not by hand. Mel Siff]

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Additionally the following, have appeared in the reaserach relative to

sinusoidal:

sinusoidal perturbations

sinusoidal force

oscillated sinusoidally

sinusoidal trajectories

sinusoidal inputs

sinusoidally oscillating

sinusoidal displacements

sinusoidal and random oscillations

sinusoidal oscillations during isometric contractions and isokinetic

movements

Hill's equation to sinusoidal oscillations

sinusoidal mechanical vibration

sinusoidal signal

volitional sinusoidal tracking

sinusoidal electrical fields

sinusoidal torque

sinusoidal length changes

sinusoidal movement

sinusoidal, displacement-controlled perturbations

sinusoidal force pulse perturbations

sinusoidal muscle stretches

sinusoidal joint movements

Regards

Dr. Zenker DC

Santa Cruz, CA