Head Velocity and Larry Sturdivan

Here I talk about Larry Sturdivan and his testimony about JFK’s head velocity.  In order to downplay a front shot scenario, the “geniuses” on the HSCA trotted out Larry Sturdivan to tell us that a bullet could not have moved JFK’s head dramatically backward. 

Well, something made his head go back and his right arm up.

It wasn’t the wind.

JFK was already listing to the left. He had been shot in the throat. His postural tone was rapidly diminishing. His blood pressure was dropping. He was dying. How much effort would it take to push him over? Not much. You probably could have pushed him over with one finger.

Let’s look at the velocity the bullet imparted to the head.

Larry Sturdivan is a Warrenatti. He has a degree in physics. He testified before the HSCA.

He initially stated that the velocity imparted to JFK’s head was 1.2 feet per second.

Mr. Sturdivan: As we can see from the chart, this velocity of 1.2 feet per second is not the kind of velocity that would throw the President bodily around backwards, forwards, or in any direction no matter which direction the bullet came from. The deposit of momentum from the bullet is not sufficient to cause any dramatic movement in any direction. It would have a very slight movement, assuming that the bullet hit him in the side of the head.

HSCA Report March 1979

His calculations to arrive at 1.2 feet per second seem unclear.

This diagram that was presented to the HSCA really makes me angry. I have watched many physics teachers write momentum equations. This is the worst. So, I had to listen to his testimony at https://www.youtube.com/watch?v=a89vRfFnGRM. It is at about 1:34 minutes in.

What bothers me is that he has attributed 800 feet per second as the speed of the bullet that will be counted towards momentum. I’m not sure how he arrived at this with precision. The bullet is capable of being fired between 1800 and 2100 feet per second. I understand that much of the bullet’s velocity will go toward’s kinetic energy, so it’s reasonable to dial down on the speed when calculating momentum.

Furthermore, he “guesses” at the weight of the head as 15 pounds, a gross overestimate. The average head weighs about 10 to 11 pounds. During that same testimony he was asked specifically about his qualifications regarding anatomy and physiology (because he has degrees in statistics and physics), and he assured the committee that he had taken courses in biology and that he had to be familiar with medical issues in the line of his work.

If we adjust the speed of the bullet to 1000 feet per second and the head weight to 10 pounds and use his equation above, we would arrive at a head velocity of

2.314 feet per second. This is significant.

I seriously doubt that one person on that HSCA had one nano-clue as to what he was talking about.

This is important because if people can’t understand your calculations in an understandable way, how can they challenge them?

I could never be a Congressman. If I had been presented with that formula, I would have had to quietly resign.

But let us accept it for now so that I can continue.

This velocity of 1.2 feet/second does not sound significant, but when you inch through the Zapruder frames, you see that the head movement is not as dramatic as when viewed in real time.

Contributing to the illusion of the dramatic kickback of the head is Zapruder’s handling of the camera, the changing angulation of the limousine, and the flipping up of JFK’s chin toward his left and front.

It seems possible that 1.2 feet per second may be significant. And even more so if the calculations are off.

Let’s compare JFK’s head in frames 314 and 323.

They are 0.5 seconds apart.

Zapruder’s camera moved at 18.3 frames per second.

Don’t go berserk here. I’m not trying to make a case for absolute precision. It’s almost impossible to get these two frames to match up perfectly.

The vertex of the head (white lines) appears to move about one foot. Much of this may be due to the torque produced to the head as evidenced by the chin flipping up. Note that the rear shoulder line (red lines) has moved much less distance.

Don’t go berserk here. I’m not trying to make a case for absolute precision. It’s almost impossible to get these two frames to match up perfectly.

If we accept Mr. Sturdivan’s calculations, the head would have moved 7.2 inches (0.5 seconds x 1.2 feet per second) which is slightly more than half of what we see here. This is enough, is it not, to suspect a front shot, even more so if he was off in his calculations?

But wait a minute. Let’s look at his revised calculations.

These are from his book, The JFK Myths A Scientific Investigation of the Kennedy Assassination.

Yes, it’s true. He has updated his figures.

I guess he didn’t think his BS was good enough.

I think he discovered that the 1.2 foot per second head velocity was too much for comfort.

Bullet weight: 10.45 grams x
Bullet speed: x 1837 feet/second = Head weight: 4000 grams x
Head Velocity

Head Velocity = 4.79 feet per second

He now states that the head could have been moving as fast as 1.463 meters per second or 4.79 feet per second. But, he adds, because the head is attached to the body, the head would only move at 3 inches per second.

Here is how I believe he revised his calculations to come up with 3 inches per second.

Bullet weight: 10.45 grams x
Bullet speed: x 1837 feet/second = Head/Body weight: 74,000 grams x Head Velocity

Head Velocity = 0.259 feet per second

I wasn’t aware that the head was attached to the body via a rigid steel rod.

Indeed, evolution has provided you with a flexible neck that can move in many directions even if your body is still. Haven’t you noticed?

Adding in the body weight of the President to the momentum equation seems less reasonable.


If the head moved at even half the 4.79 feet per second in Mr. Sturdivan’s revised calculations, it would result in what we see in the Zapruder frames I demonstrated earlier. And it would be in accordance with that revised head velocity of 2.3 feet per second I pointed out earlier.

Mr. Sturdivan believes that a bullet fired into a human head will not cause it to move much. He likens it to a vaudevillian pulling a tablecloth out from beneath the plates and silverware.


Do they hire comedians to make this stuff up?

Incidentally, a rear shot by Mr. Sturdivan’s own calculations would be expected to produce a sustained forward motion, which we do not see.

The vectors from the rear should push the head forward, left and down.

This is why they had to develop the opisthotonic reflex theory.

Thank you.

Copyright 2018 Archer Crosley All Rights Reserved

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: