It is "common" knowledge that you should use the crimping technique moderately as it it said to be over-strenous for the pulleys. But does the have any scientific data to be backed up? Everything I can read on the internet seems to refer back to one article from 2000 - which I cannot seem to locate.

Doea any one know of any research done into this? Or should we in fact be teaching beginners to crimp from day 1?

I think these are lecture/recent research notes from Purdue University engineering school.
https://engineering.purdue.edu/...ies_and_problems.pdf

It is "common" knowledge that you should use the crimping technique moderately as it it said to be over-strenous for the pulleys.

I found this quite convincing, but it's a bit of a grind to get through. You have to start at around page 23, as the first set of slides is irrelevant to the subject, but from page 23 on, it's all meat.

I think these are lecture/recent research notes from Purdue University engineering school.

https://engineering.purdue.edu/...ies_and_problems.pdf

EDIT: that page doesn't want to load right. Let me try again:

https://engineering.purdue.edu/...ies_and_problems.pdf

I have not gone into detail with the mechanical calculations in the referred presentation. BUT is it not a huge flaw that the thumb is not in the calculation at all!! It takes a huge load from the other fingers, compared to an open hold.

And I have still to see any realtime data that shows crimping results in finger damage.

So I'm still interested if anyone can empirycally backup the claim that crimping is bad.

For the sack of argument, it could perhaps save alot of injuries - I see pro-climbers using the technique for nearly all their moves!

The main problem I have with the Purdue article cited here is that the crimp that is modeled on p.28, called:

"Free Body Diagram: Crimp Grip Position"

doesn't show the hand in a position I would consider to be a "real" crimp. The cross sectional drawing shows the hand in what is still basically an open hand position. In a real crimp, the second knuckle is elevated to almost directly above the fingertip and thus much of the downward force is supported by the finger bones themselves--and not the connective tissues.

I personally find crimping to be far less damaging to my fingers than using open hand grips and the only times I have sustained pulley injuries they have resulted from open hand grips, usually when isolating one or two fingers in pockets.

Curt

Curt, and with all due respect, I remember you saying your pulley injuries occurred while open gripping.

Anyway, I think your mechanics are flawed. in a crimp, the angle between the proximal phalanx and the distal phalanx is not zero (or 180*). If the entire superincumbent weight of the body is being held up by these two bones at an acute angle, there will be a relatively large outward vector on the A2 pulley. Soft tissue maintains the angle, not bony compression.

I'm pretty sure there's nothing wrong with my view of the relevant mechanics. Soft tissue does maintain the angle between the distal phalanx and proximal phalanx, but as the angle becomes increasingly acute (and I never said it could or would become zero) less force is required to maintain that angle.

Curt

There are some studies which have given evidence that pulley injuries happen almost entirely during crimps

Please post links quickly to those multiple published studies.

I'm not sure who is giving you one star, its not me. I know, you don't care, but I wanted you to know, out of my respect for you.

The tensile force on say, flexor digitorum profundus decreases with decreasing angle between the proximal and distal phalanx. Agreed.

The outward force on the A2 pulley increases, though, as this angle decreases, for the same load. These forces are nearly perpendicular. That is what tears pulleys.

Hey--no problem. I wear my one-star ratings proudly. If what you're saying is correct (and what I've read in the literature agree with you) I'm still puzzled how I have injured both middle finger and both ring finger A2 pulleys with open hand grips--but none with crimping grips.

Some of these articles claim that the forces are 30 times higher when using the crimp grip--but never injuring a pulley in 35 years of climbing when routinely using a technique that supposedly applies 30 times the force to the pulleys makes no sense. I'm only speaking for myself, so I realize this is an anecdotal observation--but on the other hand, the sample size of grip usage is huge, over many thousands of climbs and boulder problems over 35 years.

Any thoughts on that?

Curt

I will buy one of the articles and see if it has any scientific substance :-)

But I willl completely fail to reckonize any theoretical article which does not include the load which the thumb releaves the other fingers of!!

Of course a study as you describe it is impossible, but I would think, that some data collected from climbers with pulley injuries would hint at this. But I have no such evidence :-( All I have is some really bad (in my opinion) theories, and many persons apparently clinging to these, and merely repeating what others have said.

Hey--no problem. I wear my one-star ratings proudly. If what you're saying is correct (and what I've read in the literature agree with you) I'm still puzzled how I have injured both middle finger and both ring finger A2 pulleys with open hand grips--but none with crimping grips.

Some of these articles claim that the forces are 30 times higher when using the crimp grip--but never injuring a pulley in 35 years of climbing when routinely using a technique that supposedly applies 30 times the force to the pulleys makes no sense. I'm only speaking for myself, so I realize this is an anecdotal observation--but on the other hand, the sample size of grip usage is huge, over many thousands of climbs and boulder problems over 35 years.

Any thoughts on that?

Curt

Yeah, your case is indeed puzzling. There are at least a couple possibilities:

1) Your diagnosis was wrong. Ultrasound (US) and MRI are pretty good, but still have pretty high false-positive and false-negative numbers. Perhaps 20%. Sometimes people (especially men) assume they have a certain diagnosis based on symptoms, but never get any imaging done to confirm. Really, exploratory surgery would be the "gold standard" for proper diagnosis. I don't know how you were diagnosed.

2) Faulty memory ( please don't be offended). Many times I think we grab for a handhold, and quickly pull up, flexing the PIPs quickly, while only the distal phalanx is on the hold. If the PIP angle gets to 90 deg, and the DIP is extended, you are biomechanically crimping, even if you don't fully lock down in a full-ring crimp. I think this is similar to what you described above, with you having a disagreement with the free-body diagram.

In a true open grip, the MCPs, PIPs, and DIPs all need to be obtuse angles.

(The obtuser, the better.)

The main problem I have with the Purdue article cited here is that the crimp that is modeled on p.28, called:

"Free Body Diagram: Crimp Grip Position"

doesn't show the hand in a position I would consider to be a "real" crimp. The cross sectional drawing shows the hand in what is still basically an open hand position. In a real crimp, the second knuckle is elevated to almost directly above the fingertip and thus much of the downward force is supported by the finger bones themselves--and not the connective tissues.

I personally find crimping to be far less damaging to my fingers than using open hand grips and the only times I have sustained pulley injuries they have resulted from open hand grips, usually when isolating one or two fingers in pockets.

Curt

Bingo. /thread

this man knows. Pockets tweak people. Crimping is not so bad comparatively.