Is Full Crimping Really More Dangerous for Climbers?
Hooper's Beta Ep. 1
Description:
In this video, we are going to discuss if crimping is safe, we are going to break down the crimp position, and we will discuss proper training and management of crimping.
First, we must understand that there are 3 different crimping positions: 1) the open crimp 2) closed hand crimp and 3) full crimp.
Open crimp: involves flexion of the proximal interphalangeal (PIP) joint to 90 degrees with extension of the distal interphalangeal (DIP) joint. The 5th digit (pinky) may be in this position as well, or may be in the open drag position.
Closed crimp: the PIP is in flexion (90 degrees) while the DIP is in hyperextension. The thumb is locked over the 2nd digit (index finger) near the DIP.
Full crimp: the PIP is in >90 degrees of flexion while the DIP is in Max extension. The thumb is locked over the index finger.
The error that is commonly made is the distinction between the closed hand crimp and full crimp. People often assume that a full crimp is when you place your thumb over your index finger, when that is the closed hand crimp. The full crimp, as indicated above, does involve the placement of the thumb over the index finger, but it also involves a change in the angle of your hand which creates max distal interphalangeal (DIP) extension and greater than 90 degrees of proximal interphalangeal (PIP) flexion. This positional change allows you to potentially hold onto smaller ledges but also places more pressure on the joints and the annular pulleys.
Now, it’s important to know that without the change in the angle (full crimp) but with the thumb over index finger (closed hand crimp) there is a 17% increase in grip strength while not significantly increasing the risk of injury (Quaine). This is exactly why people perform the closed/full crimp position, increased strength.
Why does this distinction matter? Simple. one of the easiest training mistakes that is made, is not understanding this distinction. Someone will tell their friend that “yeah, a full crimp increases your strength and doesn’t increase injury risk”. They are referring to the closed hand crimp, but their friend may not know that. They proceed to practice the full hand crimp, and then get an injury. So you have one person practicing the full hand crimp too often and getting injured, and another person who is mistakenly identifying their closed hand crimp as full and doing fine. This breeds a misunderstanding on what is safe and what is unsafe and is part of why crimping get’s a bad rap.
Now, in general, crimping does indeed significantly increase the load on your A2 pulleys. Do too much, and you may get injured. Not do enough, and you never signal to the body that it needs to get stronger. This precarious balance is where appropriate training comes into play. It is, essentially, load management. Remember, training, whether it be for muscles or connective tissue, is a process of degeneration (break down) and re-synthesis. If you are training hard (break down) and don’t allow for adequate rest after training (re-synthesis) you are training on tissue that is 1) not ready to handle the same levels of intensity and 2) are more prone to injury as they cannot handle the stress. This is a common method of how injuries happen.
On the flip side, if you decide you are only going to crimp on your hard projects and never train them, you have not loaded the tissue up at all, so the body is not prepared to do this position. Imagine having a power tool in your toolbox that you never use, then expect to have massive success at the hardest part of your project? Does that make sense? Absolutely not. So, why do we think that works for climbing?
With all this talk, how do we even know that crimping is safe? This is the most important question. Crimping, as mentioned earlier, places increased forces on the annular pulleys of the finger. So, let’s get scientific to help answer this question. Research by King & Lien showed “that forces acting on pulleys in the crimp position are 287 N [newton] at the A2 pulley and 226 N at the A4 pulley”. They go on to mention that the failure force of the A2 pulley is 400 newton. So, clearly, with a controlled manner of training you are placing 71.75% load on the A2 pulley. The danger is when we begin overloading the tissue or not allowing for proper re-synthesis. (King)
King & Lien also note that “a 70-kg climber shock loading a single finger would apply a force of 450N”. Clearly, this is exceeding the failure point and so yes, if you have a foot blow or you add far too much weight to your hangs, you are at risk. But, be smart, and you can increase the ability of the pulley to hold higher forces (pushing that failure point of 400N to higher values). (King)
Training is a balance. You need to know your body and know its work capacities. You need to pay attention to how much load you can take and how much rest time you need. Also, keep in mind, if you are newer to climbing, crimping is not something you want to do right away! You will quickly overload your joints and tissue and set yourself up for an injury. Be smart, be safe, and train with patients.
Thank you for reading this! Don’t forget: Train. Climb. Send. Repeat.
References
King, Elizabeth A., and John R. Lien. “Flexor Tendon Pulley Injuries in Rock Climbers.” Hand Clinics, vol. 33, no. 1, 2017, pp. 141–148., doi:10.1016/j.hcl.2016.08.006.
Quaine, F., et al. “The Thumb During the Crimp Grip.” International Journal of Sports Medicine, vol. 32, no. 01, 2010, pp. 49–53., doi:10.1055/s-0030-1267230.
Additional Resources
How to avoid crimp injuries: https://youtu.be/8dvfuGfsQ9I
How to get better at crimping: https://youtu.be/hkrat77RUm0
Disclaimer:
As always, exercises are to be performed assuming your own risk and should not be done if you feel you are at risk for injury. See a medical professional if you have concerns before starting new exercises.
Written and Presented by Jason Hooper, PT, DPT, OCS, CAFS
IG: @hoopersbetaofficial
Filming and Editing by Emile Modesitt
www.emilemodesitt.com
IG: @emile166
Special thanks to The Wall for letting us film!
IG: @thewallclimbinggym
