Forums: Climbing Information: Injury Treatment and Prevention:
Crimping evidence
RSS FeedRSS Feeds for Injury Treatment and Prevention

Premier Sponsor:

 


mitchellclimb


Oct 30, 2013, 5:52 AM
Post #1 of 23 (4225 views)
Shortcut

Registered: Jan 7, 2006
Posts: 9

Crimping evidence
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

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?


onceahardman


Oct 30, 2013, 2:42 PM
Post #2 of 23 (4116 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [mitchellclimb] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

mitchellclimb wrote:
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 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


(This post was edited by onceahardman on Oct 30, 2013, 2:46 PM)


kenr


Oct 31, 2013, 7:22 PM
Post #3 of 23 (4020 views)
Shortcut

Registered: Sep 28, 2010
Posts: 58

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

onceahardman wrote:
I think these are lecture/recent research notes from Purdue University engineering school.
https://engineering.purdue.edu/...ies_and_problems.pdf
Yes lecture notes, not an actual article. Looks like maybe it's reporting the results of Vigoroux et al, which was an actual article. I did spend some time wading thru the Vigoroux article ... felt that it was a clever approach to solve the problem ... but finally that I was basically flawed. I wrote about it on MountainProject in the last couple of years, but I'm not sure how motivated I am to chase it down now.

I think fundamentally it's a trickier problem (to deduce the forces/torques on the different muscles/tendons in a climber's finger) than those lecture notes make it appear.

Since that paper there was at least one other paper which pointed out why it's even trickier than I had felt.

But maybe those lecture notes are reporting some other approach: If so someone should find a pointer to some paper which carefully document the methodology. Just don't count on me being the one to dig through it to find the flaws.

Ken


kenr


Oct 31, 2013, 7:48 PM
Post #4 of 23 (4017 views)
Shortcut

Registered: Sep 28, 2010
Posts: 58

Re: [mitchellclimb] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

mitchellclimb wrote:
It is "common" knowledge that you should use the crimping technique moderately as it it said to be over-strenous for the pulleys.
By that argument, we should only be climbing moderately.

I bet climbing lots of 5.12 puts way more stress on A2 and A4 pulleys than most "normal" person's could be expected to stand up to.

But the human body can be very adaptive, so some humans have found is that if they carefully incrementally stress the A2 and A4 pulleys, they can slowly build stronger to stand up to remarkable forces of 5.12+ climbing.

Not sure I get the point of using crimping only "moderately", since if you're going to refuse to crimp on the hardest moves, and insist on doing them with "open" grip ... then why would you not use open grip for all the moderate moves too?

Also bear in mind that different person's finger geometry is different, so the answer of whether and when to crimp might be different.

What I do think is a bad idea is trying to latch big deadpoints or dynos with a crimp grip. Because if the crimp fails, it tends to try to "collapse" to an open grip. But the intermediate configuration the fingers then goes through is pretty wierd.
Whereas if the open grip fails, you just fall off (perhaps with some abrasion of finger skin).
So I think it's worth practicing with open grip lots.

Ken


mitchellclimb


Nov 1, 2013, 5:24 AM
Post #5 of 23 (3983 views)
Shortcut

Registered: Jan 7, 2006
Posts: 9

Re: [mitchellclimb] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

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!


(This post was edited by mitchellclimb on Nov 1, 2013, 5:25 AM)


curt


Nov 1, 2013, 11:51 AM
Post #6 of 23 (3940 views)
Shortcut

Registered: Aug 26, 2002
Posts: 18228

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (2 ratings)  
Can't Post

onceahardman wrote:
mitchellclimb wrote:
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 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

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


onceahardman


Nov 1, 2013, 2:16 PM
Post #7 of 23 (3911 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [mitchellclimb] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

mitchellclimb wrote:
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!

Frankly, when you ask for "realtime data", you are basically asking to have a bunch of climbers offer to sacrifice their pulleys by testing them to failure by loading them to failure in situ. So I think you are unlikely to accomplish that. There are some studies which have given evidence that pulley injuries happen almost entirely during crimps, and that A2 pulley injuries are very rare outside of the climbing community. I'll try to dig around.

In the meantime, we have theory. The A2 pulley is subjected to a large outward vector during crimping, and not while using the open grip. The mechanics of this are not overly complicated. I will respond a little more directly to Curt.


(This post was edited by onceahardman on Nov 1, 2013, 2:17 PM)


onceahardman


Nov 1, 2013, 2:22 PM
Post #8 of 23 (3907 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [curt] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

curt wrote:
onceahardman wrote:
mitchellclimb wrote:
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 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

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.


curt


Nov 1, 2013, 4:42 PM
Post #9 of 23 (3879 views)
Shortcut

Registered: Aug 26, 2002
Posts: 18228

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (2 ratings)  
Can't Post

onceahardman wrote:
curt wrote:
onceahardman wrote:
mitchellclimb wrote:
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 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

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


onceahardman


Nov 1, 2013, 5:50 PM
Post #10 of 23 (3858 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [curt] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

In reply to:
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

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.


kenr


Nov 2, 2013, 5:49 PM
Post #11 of 23 (3770 views)
Shortcut

Registered: Sep 28, 2010
Posts: 58

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (2 ratings)  
Can't Post

onceahardman wrote:
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.

When I carefully went through several papers about climbing grip forces, to follow up on that paper referenced in the Purdue lecture notes, I don't think I noticed any mention of or references for such a study -- and I think I then would have been very interested to follow up on anything like that (but perhaps I somehow missed it) -- and I'm still interested now.

I believe I own and have read thoroughly pretty near all the English-language books on climbing technique and training published in the last ten years, and I don't remember mention of any such studies. And while most of those books do recommend training the open grip as an alternative to the habit of crimping anything, I don't recall any suggestion that climbers could prevent almost all pulley injuries simply by avoiding crimping.


(This post was edited by kenr on Nov 2, 2013, 5:50 PM)


onceahardman


Nov 3, 2013, 4:53 AM
Post #12 of 23 (3710 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [kenr] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

In reply to:
Please post links quickly to those multiple published studies.

Until I am employed by you, I'd appreciate a respectful tone, and not being told to "quickly" post links, or anything else.

Google scholar using search terms like: 'crimp pully injury' yields some that I have read before at the med school library here. I will not purchase them for you.

http://www.sciencedirect.com/...ii/S0363502306002474

http://www.sciencedirect.com/...ii/S0021929000001846

http://www.sciencedirect.com/...ii/S0021929005004033


There are about 2100 articles available using those keywords. Other combinations may yield more.

If, however, you are looking for a study in which 100+ live human pulleys are loaded to pulley failure in the crimp vs open position, well, there is obviously no such study. Perhaps you should fund such a study through your local medical school. Do the work if you want answers, and stop being so demanding that others produce the information you seek.


(This post was edited by onceahardman on Nov 3, 2013, 6:33 AM)


mitchellclimb


Nov 4, 2013, 5:06 AM
Post #13 of 23 (3616 views)
Shortcut

Registered: Jan 7, 2006
Posts: 9

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

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.


curt


Nov 4, 2013, 12:58 PM
Post #14 of 23 (3563 views)
Shortcut

Registered: Aug 26, 2002
Posts: 18228

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

onceahardman wrote:
In reply to:
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

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


lena_chita
Moderator

Nov 4, 2013, 1:32 PM
Post #15 of 23 (3551 views)
Shortcut

Registered: Jun 27, 2006
Posts: 5653

Re: [curt] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

curt wrote:
onceahardman wrote:
In reply to:
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

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 have no credentials to contribute to the discussion, but my experience is the same as yours. The only time I had a pulley injury was from an open-grip 3 finger pocket, not from crimping. I don't think your experience, or mine, is unique. There is a reason why people talk about 'tweaky pockets"...

But, maybe it has something to do not just with the grip itself, but with how you get to it, in real-life climbing? I have never seen anyone dyno to a full thumb-locked crimp. it is usually a delicate slow process to get your fingers on the little crimp just so, massage it, to find the marginally-better spot, and lock in. Whereas for the pockets you often go dynamically, and "stab" them, for lack of a better term.

Also I would imagine it very likely that an open-hand grip on a 2-3 finger pocket, with the other two fingers being held away from the holding fingers, due to the geometric configuration of a pocket puts a lot more strain on those fingers than a crimp where, even if only 2-3 of your fingertips are actually fitting on the crimp, you have the fingers on either side of the gripping fingers press in and support the fingers that are bearing the load.

With this in mind, I can see that both statements can be true:

--in artificial hangboard-type situation, where there is no momentum involved in getting your fingers to the hold and positioning them on the hold carefully, open-handed grip puts less strain on the fingers than a crimp does.

--in real-life climbing scenario, you are more likely to tweak your tendon on an open-hand grip, because of how you go for the hold.


onceahardman


Nov 4, 2013, 1:57 PM
Post #16 of 23 (3539 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [mitchellclimb] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

mitchellclimb wrote:
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.

Sometimes you can root around a little, and find free access by registering as a "guest".

What you say about the thumb is not really as relevant as you think. Of course using the thumb takes a lot of the weight off the fingers, and should reduce injury risk. I have never hear of a thumb pulley tear. Of course, thumb has only two phalanges...

Anyway, using the thumb does not change the relevant geometry of the fingers. Flexing the PIP maximally while extending the DIP maximally and passively puts huge loads on the A2. These loads will be less if you use the thumb, yes, but they will still be much higher than an open grip.


onceahardman


Nov 4, 2013, 2:12 PM
Post #17 of 23 (3536 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [curt] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

curt wrote:
onceahardman wrote:
In reply to:
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

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

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.)


(This post was edited by onceahardman on Nov 4, 2013, 2:22 PM)


hyhuu


Nov 5, 2013, 5:10 AM
Post #18 of 23 (3457 views)
Shortcut

Registered: Jul 25, 2001
Posts: 491

Re: [mitchellclimb] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

It would be interesting to hear directly from those who actually experienced injuries from crimping. My injuries and fromn those who I know were not due to crimping. I don't doubt that crimping put a great stress on the fingers. However, what I found is that as I get tired, I mostly just fall off the hold when I try to crank on it. For pockets and other open hand holds (except for slopper), I can still really pull on them even when I'm tired and that's where all of my injuries have come from.


amarius


Nov 5, 2013, 7:44 AM
Post #19 of 23 (3429 views)
Shortcut

Registered: Feb 23, 2012
Posts: 107

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Thanks for posting links to those articles.

One observation - fingers have different lengths. It sort of leads to different angles between phalanges for different fingers in a particular grip. Since those angles, according to quoted studies, determine loads on both pulleys and tendons, perhaps looking at distribution of which finger got injured would help to understand which angles are statistically more dangerous.


curt


Nov 5, 2013, 9:18 AM
Post #20 of 23 (3407 views)
Shortcut

Registered: Aug 26, 2002
Posts: 18228

Re: [onceahardman] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

onceahardman wrote:
curt wrote:
onceahardman wrote:
In reply to:
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

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

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.)

Thanks, I certainly don't know. However, having now read the posts of both lena_chita and hyhuu, who have similarly also only injured pulleys/fingers from employing open-hand holds, I'm going to continue to question the wisdom of using open hand holds as opposed to crimps.

Somehow, the literature and real world experience don't seem to be aligned very well here.

Curt


mitchellclimb


Nov 5, 2013, 11:17 PM
Post #21 of 23 (3331 views)
Shortcut

Registered: Jan 7, 2006
Posts: 9

Re: [curt] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

There is much more stress on the fingers whilst crimping, true, but not necessarily on the finger tendons or pulleys. You feel the crimping pressure as it is on tissue with nerve cells, you will not feel any force on tendons/pulleys before it is too late (not many nerve cells).

Do the math with the thumb, and I will guarantee you that you will find the load to be substantially lower than open hand - and the little empircal evindence there is backs it up!

All I need to find out now is why so many persons claim this myth, and stick to bad therotical calculations. My guess is hear-say and obstinacy :-)


5.samadhi


Nov 9, 2013, 3:46 PM
Post #22 of 23 (3088 views)
Shortcut

Registered: Jul 31, 2011
Posts: 98

Re: [curt] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

curt wrote:
onceahardman wrote:
mitchellclimb wrote:
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 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

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.


onceahardman


Nov 10, 2013, 2:08 PM
Post #23 of 23 (3001 views)
Shortcut

Registered: Aug 3, 2007
Posts: 2469

Re: [5.samadhi] Crimping evidence [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (1 rating)  
Can't Post

5.samadhi wrote:
curt wrote:
onceahardman wrote:
mitchellclimb wrote:
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 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

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.


Lookie here:

I don't deny that people injure their fingers climbing pockets. My point is narrower. I think, based on the physics, and the peer-reviewed literature and my personal experience, that pulley injuries usually occur in climbers as a result of crimping.

What happens in pockets is a red herring in this narrow discussion.

My personal opinion is that pocket injuries are generally tendon and/or ligament, not pulley injuries.

If no proper diagnosis is made, no real conclusion can be drawn..


(This post was edited by onceahardman on Nov 10, 2013, 2:15 PM)


Forums : Climbing Information : Injury Treatment and Prevention

 


Search for (options)

Log In:

Username:
Password: Remember me:

Go Register
Go Lost Password?



Follow us on Twiter Become a Fan on Facebook