Key takeaways
- A finger lock wedges and torques the fingers in a thin crack for a secure hold.
- It's used in finger-width cracks too narrow for a hand jam.
- Twisting the hand cams the fingers against the crack walls for a solid 'lock'.
- It can feel surprisingly bomber but is hard on finger joints and skin; tape can help.
What a finger lock is
A finger lock is a crack-climbing technique in which you slot your fingers into a thin crack and torque or cam them — often by twisting the hand so the fingers wedge against the crack walls — to create a secure hold. It’s used in finger-width cracks too narrow for a hand jam.
How to do one
Slot your fingers into the thin crack (typically thumb-down), then twist or cam your hand so the fingers wedge and lock against the walls — the torque is what makes it secure. Find a spot where the crack constricts or your fingers can cam, trust the lock, and use your feet to take weight off your fingers.
On a thin crack too narrow for a hand jam, a climber slots two fingers in thumb-down, torques their hand to cam the fingers solidly against the walls, weights the surprisingly bomber lock, and steps up on a foot jam to reach the next finger lock above.
Technique and the hands
Finger locks concentrate force on the finger joints and tendons and the rough rock scrapes skin, so thin crack climbing is demanding on the hands. Climbers often tape up, use footwork to offload the fingers, and build the specific strength gradually. It’s a form of jamming for the thinnest cracks, distinct from face-climbing grips like the crimp.
The bottom line
A finger lock is how you climb thin cracks: slot your fingers in and torque your hand so they cam against the walls into a secure lock, where a crack is too narrow for a hand jam. Set well, it's surprisingly bomber — but it's hard on the finger joints and skin, so tape up, use your feet, and build finger strength gradually for thin crack climbing.
Frequently asked questions
What is a finger lock?
A finger lock is a crack-climbing technique where you slot your fingers into a thin crack and torque or cam them to wedge against the crack walls, creating a secure hold. It's used in finger-width cracks that are too narrow to fit a whole hand for a hand jam. A well-set finger lock can feel surprisingly solid.
How do you do a finger lock?
Slot your fingers into the thin crack, typically thumb-down, then twist or cam your hand so the fingers wedge and lock against the walls of the crack. The torque is what makes it secure. Finding the right spot in the crack (where it's slightly constricted or your fingers can cam) and trusting the lock are key, as is using your feet to take weight off your fingers.
Are finger locks hard on your hands?
They can be — finger locks concentrate force and torque on the finger joints and tendons, and the rough rock can scrape the skin, so thin crack climbing is demanding on the hands. Climbers often tape their fingers for protection and build the specific strength gradually. Setting locks well and using footwork to offload the fingers reduce strain and injury risk.
Sources
- Crack technique — American Alpine Club
- Climbing skills — The Mountaineers