A Little Chiropractic Physics: be wary when you F with the ma

A Little Chiropractic Physics: be wary when you F with the ma

A Newton, big N, is the measure of force.

It is named after a famous fig cookie… not, sorry, a bit of misunderstanding. It is named after Issac Newton from the second law of motion. F = m*a. Force equal mass time acceleration.

How much force does chiropractic generate with high-velocity-low-amplitude manipulations?

They aim for about 400 to 600 Newtons when teaching chiropractic students, although this force only lasts for about 135 milliseconds.

But just how many cookies does 400–500 Newtons represent?

A kilogram of cookies has 9.8 Newtons.

A 70 kg human? 686 Newtons. That is the force measured on the bottom of the feet as you stand on the ground.

Move the force measurement to the neck. If you were to suspend a body by the neck with a noose, the force measured at spine and surrounding soft tissues would also be 686 Newtons.

For a brief period of time, chiropractic applies 58% to 87% of the force of a suspended hanging.

A judicial hanging has drop, and this leads to a force of around 1200 N, "sufficient to produce a subluxation of C2 and C3 vertebra."

I suspect that would be a subluxation refractory to chiropractic.

Is there any other similar injury to chiropractic? Perhaps Whiplash, where a sudden force is applied to a relaxed neck.

Postmortem studies have shown that vertebral artery lesions are found in about one third of fatally injured road traffic accident victims with vertebral atlas injury. In previous reports, neurological deficits or death have followed posterior neck injuries by up to 8 days after the accident.

Although the measured forces I have found in whiplash a much higher.

Chiropractic manipulation, hanging and whiplash are on a continuum of forces, with a continuum of injuries.  Like stroke, for no matter how much the chiropractors might say otherwise, when you F with the ma, injuries can occur.

Points of Interest 04/13/2016
Points of Interest 04/12/2016

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