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What Is Stemming In Climbing?

LAST UPDATED: 23rd August 2023

Stemming is a very focused climbing technique that is typically used in chimneys and dihedrals; where two walls provide a venue for oppositional pressure between the hands and/or feet. It can be a scary place to put yourself in, but in some situations, there is no other choice. With that in mind, let’s talk about stemming and try to bring the boogieman out of the closet and into the light.

When Do I Need To Stem In Rock Climbing?

Chimneys

There are very few chimney pitches in the world that will NOT require at least a little bit of stemming. A chimney is a wide, parallel-sided crack that you can fit your whole body into. When climbing a chimney, a climber must turn themselves into a wedge to keep from falling. Take, for instance, a chimney that measures between three or four feet across. This is the perfect venue for stemming, i.e., using your arms, legs and even your back to bridge the gap between the two walls.

climber stemming in chimney rock climbing

Bombay Chimney

A Bombay chimney is wider at the bottom and becomes narrower as you climb up. In these types of chimneys, a combination of all the techniques mentioned below will probably be used.

Dihedrals

Corners, or dihedrals, are an entirely different monster. Whereas the opposing forces required to climb a parallel-sided chimney are obvious, an angled corner system is much more thoughtful. The climbing mechanics between these two features are the same: by pushing against both walls with the hands and feet, a climber wedges themselves into a constriction. However, at 90-degrees or wider, exerting opposing forces on either side of a corner is much more difficult.

Tommy Caldwell on The Dawn Wall
Tommy on the Dawn Wall with Kevin Jorgeson ©CoreyRich

90 Degrees & Above

For the sake of argument, picture a corner with a 100-degree angle where the two walls meet. If you pushed straight into both walls, you wouldn’t even be able to get off the ground. Here, perpendicular forces, like those used in chimney climbing, cannot generate enough counterpressure to keep a climber on the wall. Instead, both perpendicular and lateral forces need to be applied at the same time.

Lateral force means sideways; exerting an almost parallel force on the rock. This direction of force relies mostly on the texture of the rock and friction generated by its contact with the hands and feet. By simultaneously pushing both in (perpendicular) and alongside (lateral) the rock, friction and opposing forces combine to keep the climber on.

Stemming In Rock Climbing: A How To Guide

Okay so now we know in which situation we might need to do some stemming, but how do you stem? Similarly to going up a dihedral, stemming requires the use of different body parts, or all body parts if you are desperate. No judgments here. I’m partial to a butt shuffle every now and then. Anyway, here are all the different ways you can stem, butts and all.

Legs

Using the legs as the foundation for stemming is the most traditional example of this method. By placing one foot more or less flat against the wall, one foot against the other and pushing, you can wedge yourself into the crack by way of opposing forces. On that note, don’t skip leg day at the gym!

Climber stemming with legs on dihedral

Arms & Hands

The same principle applies to your arms and hands. Often, the counterforce generated by the legs is not quite enough to make you feel secure and the hands must be used. One hand against one wall, one hand against the other and push. This reduces the strain on your legs and distributes it across the body more evenly.

Back/Butt

What if the crack is too narrow to get good leverage with the hands and feet? Well, you have to get creative! Start by facing one of the walls. Plant your hands and feet against it and paste your back against the other side. When you push, you’ll notice that the pressure exerted against both walls will keep you from falling.

girl climber stemming on rock

There have been times when, in a narrow enough chimney, I have been forced to face one wall and put only one leg out in front. By bending the other leg and placing that foot on the wall behind me, I was able to ascend the chimney. The benefit of this method is that the back can be used provisionally too.

Knees

Some chimneys are wide enough to admit the upper body (shoulders, chest, stomach, etc.), but are too narrow to use any of the above stemming techniques. In cases like this, although it can be very painful, the knees come in handy. Plant the back against one wall, then bring your knees up until they contact the opposing wall. When they are situated, lift your feet and plant them behind you on the same wall that your back rests on. Using your arms and shoulders to push as well, you can shimmy upward.

Palming

When pushing laterally with the hands, you’ll want to use most of the hand, maximizing the amount of skin in contact with the rock. Little dishes, vertical edges and even the smallest undulations in the rock – when pressed into with the palm – can be used to balance out the pressure being applied by the other side of the body.

Smearing

As opposed to edging (standing on a horizontal edge in the rock with your toes), smearing involves pasting the sole of your climbing shoes on the rock, using friction between the two to stay upright.

Catherine Destivelle on Devil’s Tower ©Catherine Destivelle Collection

I know what you’re thinking – that sounds insecure as hell! And you’re right! Inside a corner, it is downright terrifying. Smearing in a wide-angle corner requires a dizzying combination of all the forces mentioned above: perpendicular, lateral and frictional. By pressing into and alongside the rock with your foot flat against the wall may sound like sorcery, and it will probably feel impossible at first. But the more you get used to trusting the rubber on your shoes, the more intuitive it becomes.

Here is a quick explanation of what stemming in rock climbing is!

Now You’ve Mastered Stemming In Climbing!

While stemming is only useful in a few climbing disciplines, it’s always good to have a few tricks up your sleeve when faced with a chimney or dihedral. Play around with each of these techniques; the answer to a tough stemming problem is probably in some combination of them all. And, if you are ever unsure, make sure to practice them on top rope before heading out on lead! Stemming will often challenge your head more than your body, so get that head game up!

Header image: ©Andrew Burr

 

ZaK

Born and raised in Northern Vermont, Zak's parents were hardcore adventurers, and the appearance of a child in their lives did not slow them down much. Each summer, they would toss him and an assortment of gear in the truck and gun it for the American West. After his first year at college, Zak applied for a job in Yosemite National Park, and for the next decade, he worked seasonally in Yosemite and on the Sierra Eastside, doing whatever he could to be close to those mountains. Currently, Zak lives on the north shore of Lake Tahoe, piecing together a living as a climbing guide, bartender and writer.

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