UKC

My morning wondering is this:

Climbers often conceptualise our movement as being somewhat dualistic, of either dynamic or static style. Yet surely there can be no such differentiation by inference of movement being…movement.

i.e. all movement is dynamic, no movement is static.

So a thought really but what other ways of describing movements are there?

I guess static movements in climbing are where you're not really moving your body to make a move just one of your limbs, whereas dynamic movements are where you're moving your whole body (including your limbs). So, in a way you're right but I think it's a useful bit of climbing terminology.

What climbers actually mean is that a movement is either quasi-static or non-quasi-static.  If a movement is quasi-static you could stop the movement at any point and hold the position; you are moving through a series of equilibrium positions, whereas during a dynamic movement you are not.

You are correct of course.

However the way I think of it is that dynamic movement uses momentum to complete the move, the centre of gravity is moved to outside the body, and were it not for the added momentum the body would be off balance and fall.

Static movement doesn't use momentum.

Solid or squishy

Good explanation, thx. I was pondering the OP's question too, recently.

Just for fun, I'd like to edit your response:

"In a static move, you can stop at any point and hold your position. In a dynamic move, you can't." 

Cheers

Al

Made me burst out laughing when I got it... Thanks for the morning chuckle!

Have a good day!

Thank you. I think my disliker has the squits ... ?

I don't think this is a good way of thinking about it. Firstly it is possible to be in a position with your centre of gravity outside your body and yet be perfectly stable - for example on an overhang with high feet and low hips. Equally it is surely possible to complete a dynamic move without your centre of gravity ever being outside your body.

I agree though that the characteristic of dynamic moves is that the intermediate positions would not be stable (or that you would not have the strength to maintain them).

Your centre of gravity is rarely outside your body, even in your overhang scenario. Unless you manage to contort yourself almost into a ring it will generally be somewhere within your torso!

The key question is whether the vector of your weight (a force!) runs through the supporting body part (what that is again depends on your posture).

IMO the best practical distinction between dynamic and static moves is that dynamic moves make use of momentum in some way.

Maybe I have misunderstood you, but there are plenty of equilibrium positions where that will not be the case. Just standing with your feet apart for example.

I think that is consistent with my definition - if you are moving through non-equilibrium positions, then you must be moving so you must have momentum.

OK, you have successfully out-pedanted me!

...where the vector of your weight runs through the area defined by the parts of your body supporting you.

CB

Dynamic moves are accompanied by grunts, power-screams and shouts of "Allez" and "Send it".

Static moves are silent.

Even that doesn't work; on a vertical wall your weight vector cannot pass through the plane defined by any set of points on the wall.

What matters for equilibrium is that all forces and moments balance. For example you can be stable on a vertical wall with only your left hand and left foot in contact, but you will need to apply small moments through your grip to stop yourself swinging.

Still, my original point stands: The centre of gravity of your body will be well within your body.

I agree with your equilibrium argument, even though it is not sufficient: You will e.g. be transiently in equilibrium when deadpointing (actually, that is the whole point of that technique).

CB

If I were writing video analysis software to identify a climber's movement as dynamic or static, I would probably classify it based on the magnitude of the climber's acceleration vector.

I disagree. That is like saying a ball thrown vertically upwards is in equilibrium at its high point; it is not.

But even climbing entirely quasi-statically you must be accelerating at times.

Which is why the whole static/dynamic question is grey. Climbing fast you absolutely are using momentum, even for moves that would be classified as "static".

One thought I have is maybe the static<->dynamic spectrum in the context we want would be that all that is that on the fully static end your muscles are performing the movement while on the fully dynamic end your movement is entirely due to momentum on at least some axis (i.e. you could still be pulling to alter the trajectory).

Moves are rarely fully static.

I think you'd find it difficult to translate that into anything rigorous (in the sense of physics). The right answer (IMHO) has already been given above: If you can stop the move at any point and hold that position, then you're climbing statically. If not, dynamically.

I tend to climb outdoor onsight trad completely statically (cowardly punter). On chossy rock, it's the only way (that isn't suicidal).

Sure but as soon as you start adding speed to the equation things get iffy. You can stop a lot of things with enough strength, doesn't mean momentum isn't at play in the movement.

Sure, so do I on bad rock, but I do that by moving intentionally slowly.

I like Nikolai Bernstein's phrase, 'posture is a preparation for action'

That's why couching the difference between static and dynamic (climbing terms) in term of 'momentum' (a physics term) is at best futile and at probably misleading/confusing. It make more sense to define climbing terms by referencing terminology that is meaningful in climbing (actions, motivations...)

It's a spectrum.

Also, not sure why you have all the dislikes. I suppose some people object to talking about climbing on the climbing forum these days... 

perhaps...

Stable Static: using muscles to maintain posture only  (Standing; sitting)

Unstable Static: Muscle activity required to maintain contact (holding a hold to maintain position; feet not flat on surface) (thinking about this, standing might be seen as belonging to next category)

Stable Movement: Changing position, but can stop at any time and reverse

Active Dynamic Movement: A dyno, jumping (including down),

Passive Dynamic movement: Falling (planned, unplanned), abseiling, dropping/sliding

I turned that like/dislike option off some time back, not sure why it's even a thing

I quite like your idea of stable and dynamic movement