Skull crusher
Also known as: Lying triceps extension
A lying triceps extension that loads the long head of the triceps at length.
What it is
A lying extension in which you lower a barbell, EZ bar or dumbbells towards your forehead or behind your head, then extend the elbows. Taking the bar behind the head stretches the long head of the triceps, which is the portion least worked by pressing.
Muscles worked
Primary: Triceps. Secondary: Front deltoids.
How to perform it
- Lie on a bench holding an EZ bar with a shoulder-width grip, arms extended over your chest.
- Tilt the arms slightly back towards your head so there is tension on the triceps at the start.
- Bend only at the elbows, lowering the bar towards your forehead or just past it behind your head.
- Extend the elbows to return, stopping just short of a hard lockout to keep tension on the muscle.
Common form faults
- Elbows flaring outwards as you lower. Keep the elbows pointing forward and roughly the same width throughout; flaring turns it into an inefficient press.
- Moving the upper arms so it becomes a pullover. Only the forearms should travel. Reduce the load until you can hold the upper arms still.
- Elbow pain from a straight bar. Use an EZ bar or dumbbells with a neutral grip — the wrist and elbow position is far more comfortable for most people.
Programming
A triceps accessory in moderate to higher reps. Lowering behind the head rather than to the forehead increases the stretch on the long head, which appears to be the more productive version for growth.
Plan your training
Variations & substitutions
Frequently asked questions
- Why does my elbow hurt doing these?
- Usually a straight bar forcing the wrists into pronation, or too much load. Switch to an EZ bar or dumbbells, reduce the weight, and control the lowering.
- To the forehead or behind the head?
- Behind the head gives a longer stretch on the long head of the triceps, and research on training at long muscle lengths suggests that is the better option for growth.
Written and reviewed by Mathew Beale, MSc Biotechnology, University of Reading.
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